Medical Microbiology and immunology Chapter Ch. 3
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I normally do a quick A&P 1 and A&P 2 review for the first several lectures.
We are going to review Ch. 3 - Cells.
We are going to run through all these organelles.
1. Microvilli (pl.) or microvillus (s.) - fingerlike extensions that increase surface area for
absorption
An increase in surface allows for more space to absorb materials such as nutrients.
Note: The small intestine has microvilli in order to absorb nutrients better.
2. Centrosomes (entire unit) or centrioles (cylindrical structures)
- needed for cell division (reproduction)
e.g. Gonads (animals)
Females --> ovaries
Males --> testes
Note: Not all cells have centrosomes/centrioles.
e.g. Red blood cell (RBC) - missing centrioles --> cell division is not possible
e.g. Neurons (make up nervous system) - missing centrioles --> no cell division
3. Cillia (pl.) or cillium (s.) - long extensions (longer than microvilli) and they MOVE
materials across the surface of the cell
Note: The microvilli does not move at all!
Is that clear on the difference between microvilli and cillia?
4. Proteasomes - hollow cylinders to breakdown and recycle materials
5. Ribosomes - make proteins
a. Fixed ribosomes - attached to the ER
b. Free ribosomes - floating around in the cytoplasm (or cytosol)
Do you remember what ER stands for?
transport?
Meng, that is 1 of the possible functions of the ER = endoplasmic reticulum.
6. Endoplasmic reticulum (ER) - synthesis, storage, and transport of materials
a. Rough endoplasmic reticulum (RER) - makes proteins (fixed ribosomes make proteins)
b. Smooth endoplasmic reticulum (SER) - makes lipids and carbohydrates
What is a lipid?
Lipids - made of fats and oils
What is a carbohydrate?
What else?
Carbohydrates - sugars and starches
7. Nucleus - contains DNA and controls the functions of the organelles and the cell
"Brain" of the cell.
What does DNA stand for?
DNA = deoxyribonucleic acid (original genetic material and is usually double stranded)
RNA = ribonucleic acid (copy of DNA)
The DNA always stays inside the nucleus and never leaves the nucleus.
However, there is a "nucleolus" inside the nucleus.
What does the nucleolus do here?
Nucleus - makes and stores DNA
Nucleolus - make RNA (copy of DNA)
The RNA is allowed to leave the nucleus through the nuclear pores and enter the
cytoplasm.
Reason: The cell may need the DNA information (comes from RNA) to make proteins.
Do you remember the names of these processes?
A. Replication
B. Transcription
C. Translation
A. Replication: DNA  DNA (cell division where both daughter cells must receive the
original DNA)
Both in mitosis (somatic cell division) and meiosis (gamete cell division)
somatic - body cells
gamete - sex cells (egg or sperm)
B. Transcription: DNA  RNA (occurs frequently in the lifespan of the cell)
C. Translation: RNA  Proteins
RNA (nucleotides of A, U, G, C) being translated in Proteins (20 possible amino acids)
nuclear envelope/nuclear membrane - cell membrane of the nucleus
nucleoplasm - cytoplasm of nucleus
Do you know the difference between "chromatin" and "chromosome"?
More in what way?
chromatin - loose DNA (readily available and accessible by the cell)
e.g. You have your toothbrush in the bathroom and the comforter in the bedroom.
vs.
chromosome - compact DNA (not readily accessible but easy to move around such as in
cell division)
e.g. You have all your stuff packed in boxes (moving to a new home) so it is easy to
move everything
Question: Can you find your toothbrush among those many packed boxes?
chromatid - copy of DNA found within the chromosome
You have 2 chromatids to be split between 2 daughter cells.
Is that clear so far?
8. Golgi apparatus/Golgi complex - stacks of flattened membranes --> packaging of
products (storage also)
e.g. Doritos --> packaged product
e.g. Corn - raw product (from the farm fields)
ER makes the raw products of proteins, lipids, and carbohydrates.
Golgi apparatus - packages these raw products in many different forms...
e.g. Lipoprotein = Lipid + Protein
e.g. Glycolipid = Carbohydrate + Lipid
e.g. Phospholipid = Phosphate + Lipid (major component of cell membranes)
Do you understand what the Golgi apparatus does in terms of packaging raw products
into a finalized product?
The Golgi apparatus has the ability to make enzymes (proteins that function in a specific
way).
In fact, most WBCs have Golgi apparatus produce toxic enzymes that will pathogens.
Pathogens - something that is contagious and causes disease or illness
e.g. bacteria, virus, protozoa, molds/fungus, etc.
What does COVID-19 stand for?
CO = coronavirus
Typo: COVI = coronavirus
D = disease
19 = 2019 (when it was first discovered)
9. Mitochondria - powerhouse of the cell that makes ATP energy
What does ATP stand for?
ATP = A-P-P-P
ATP = adenosine triphosphate
10. Peroxisomes - neutralizes or removes toxic compounds (e.g. poisons)
This is like the "liver" of the cell.
What is a vesicle?
A vesicle is basically a "bubble" found in the cytoplasm.
1. Empty vescicle
2. Vesicle that contains nutrients
3. Vesicle that contains enzymes (proteins that speed up a chemical reaction)
a. Peroxisomes - neutralizing enzymes to remove toxins
b. Lysosomes - digestive enzymes to digest nutrients, breakdown damaged organelles, or
destroy pathogens
11. Lysosomes - vesicle that contains digestive enzymes
This is like the "stomach" of cell.
Is this clear so far?
12. Cytoskeleton - made of fibers that gives the cells shape, structure, and support
This is like the "bones" of the cell.
a. Microfilaments
b. Microtubules (also found in the centrioles)
c. Actin - thin filaments (found in muscles)
d. Myosin - thick filaments (found in muscles)
e. Desmin - intermediate filaments
13. Cell membrane/Plasma membrane - covering of the cell that is selectively
permeable to substances
This is like the "skin" of the cell.
The cell membrane is made of a "phospholipid bilayer membrane".
red balls --> phosphates
black lines --> lipids (fatty acid tails)
blue structure --> membrane proteins that acts as "gates" to control entry or exit of
materials in the cell
Let's put all this together.
1. Nucleus - make DNA
a. Replication: DNA --> DNA
b. Transcription (nucleolus): DNA --> RNA
2. RNA leaves the nucleus and attaches to a "free ribosome" or "fixed ribosome".
3. Transcription: RNA (with the help of ribosomes) --> Proteins
4. Protein is folded into the correct shape inside the RER.
5. RER sends the protein via a vesicle to the Golgi appartus
6. The ER vesicle reaches the cis side of the Gogli apparatus/complex.
7. Golgi apparatus packages the raw products into a final product.
e.g. RER sends proteins and the SER sends carbohydrates so that the Golgi apparatus
combines it as a "glycoprotein".
Victoria Ying
1:07 PM
8. The vesicle leaves the Golgi apparatus on the trans side
Note: The Golgi complex has the ability to make new organelles such as: 1. lysosomes
and 2. peroxisomes.
9. Outcomes of these vesicles:
a. Empty vesicle - membrane fusion with the cell membrane to create a larger cell
b. Exocytosis - fusion of the vesicle with the cell membrane to empty the contents
c. Creation of new organelles - stays inside the cell
i. Lysosome - vesicle with digestive enzymes
ii. Peroxisome - vesicle with neutralizing enzymes
Do you now have a better understanding of the Golgi apparatus/complex?
Let's focus on what happens if the Golgi apparatus creates a "lysosome".
1. Fusion of damaged organelle with a lysosome --> breakdown or possible recycling
of materials to generate new organelles in the future
a. Reabsorption - recycle the materials
b. Exocytosis - eject or get rid of the products (no longer useful)
2. Fusion of solid materials (nutrients or pathogens) - breakdown or destroy before
exocytosing the contents out
a. Reabsorption - use the digested nutrients
b. Exocytosis - eject or get rid of the destroyed pathogen
Note: This exocytosis of destroyed pathogens occurs in most WBCs (white blood cells).
3. Autolysis - self-cell destruction (committing suicide)
a. Physical trauma, damage, or crushing injury --> autolysis where the cells automatically
release digestive enzymes and the cell dies
Note: A better way for the cell to die is by "apoptosis" - programmed cell death.
Analogy:
Autolysis - freak accident that leads to death (very sudden and unplanned for) --> Leads
to lots of issues and problems
That is dying by aging.
vs.
Apoptosis - programmed cell (planning a will when you know you will die within a few
months)
e.g. The doctor says you have brain cancer and have about 1 more month to live...
Apoptosis - the cell cleans up and destroys everything inside before it dies...
vs.
Necrosis (autolysis) - all the contents spill out and the cell dies and leaves a huge mess
behind
Is that clear so far?
Nowadays we all have cell phones.
Do you remember the bases found in DNA and RNA and how they pair with each other?
DNA: A, G, C, and T (only in DNA)
Note: DNA and RNA must be all capital letters.
Bases:
A - adenine
G - guanine
C - cytosine
T - thymine
vs.
RNA: A, G, C, and U (only in RNA)
If you see a T, it must be DNA (original information)
If you see a U, it must be RNA (copy of DNA).
This allows the cell to know which is the original or which is the copy.
Base pairing rules:
DNA: A-T or T-A
RNA: A-U or U-A
Pneumonic: AT&T phone
and
DNA and RNA: G-C or C-G
Pneumonic: GNC vitamin store
N sounds like "and".
Does that help?
Table 3-1 (slide 37) shows DNA triplets.
tri = 3
triplet - consists of 3 bases
DNA: choices are A, G, C, or T
RNA: choices are A, G, C, or U
1. Template strand (original DNA) - AAA
2. Coding strand (original DNA - complementary to the template strand) - TTT
Reminder: DNA comes as double stranded
3. mRNA or messenger RNA - triplet is called "codon" - codes for information
m - lower case
RNA - all upper case letters
Let's review the 3 types of RNA before we continue with the rest of Table 3-1.
1. mRNA or messenger RNA - linear (line) and is like a "recipe"
2. tRNA or transfer RNA - clover leaf shape and is like the "ingredients" (amino acids to
build the protein)
Going back to mRNA, the start codon is always AUG.
Pneumonic: AUG reminds me that school starts in August.
Let's go back to tRNA that needs to pair with mRNA.
If mRNA codon is AUG.
What is the complementary base pairing or tRNA anticodon?
1. mRNA or messenger RNA - linear (line) and is like a "recipe"
2. tRNA or transfer RNA - clover leaf shape and is like the "ingredients" (amino acids to
build the protein)
3. rRNA or ribosomal RNA - small and large subunit that stabilizes all the RNA and
amino acids to build the protein
rRNA is like the "kitchen".
These are the steps of Translation (RNA --> Proteins)
1. Initiation - bring the mRNA, tRNA, rRNA, and amino acids together
2. Elongation - form the peptide bond between the 2 amino acids (lengthening the protein
chain)
3. Translocation - move one codon over to allow another tRNA to bring in another amino
acid
Note: Steps 2 and 3 repeat over and over again until the protein is completed.
4. Termination - release the completed protein (polypeptide) and the mRNA, tRNA, and
rRNA all disassemble
I just stopped the video. Did you see RNA move in the background?
Does the video help give you an idea how translation works?
rRNA = small and large subunits (position switches all the time)
Reason: Sometimes proteins are made upside down or right side up.
What is diffusion?
diffusion - movement from high to low concentration
This is a natural process that does not require ATP energy.
e.g. Let the ball down roll the hill.
What is osmosis?
Yue is correct is the particles are too large to move through a semipermeable membrane.
However, if the particles are small enough to move, then the definition Yue provided is
not entirely correct.
Osmosis - diffusion through a semi-permeable membrane
A - left side is less concentrated (mostly water and less solute)
More blue (H2O) than purple present.
Is the H2O able to pass through the selectively permeable membrane?
Is the purple solute able to pass through?
That means only water is able to travel in this situation.
So Yue's definition about H2O movement only is correct.
However, if the solute was small enough to travel through the selectively permeable
membrane, then you have to look at the diffusion of both H2O and the solute.
A - dilute (less concentrated)
B - concentration (more solute)
So the H2O travels from low concentration of solute (high H2O concentration) --> high
concentration of solute (low H2O concentration)
This is reverse thinking of diffusion all because the solute cannot move or pass through.
Do you understand so far?
osmotic pressure - force applied to oppose or stop osmosis in order to keep the solution
levels the same in A and B (both sides)
Conclusion: More concentrated substances or solutions will draw in more H2O and so
more pressure needs to be applied to stop the H2O from coming in...
Summarize:
High osmotic pressure = High concentration (solute)
Do you remember the RBC experiment in 3 types of solutions based on concentrations
from A&P 1 class?
1. Isotonic
2. Hypotonic
3. Hypertonic
1. Isotonic solution - same concentration as the RBC inside
Result: Biconcave disc (no change shape)
2. Hypotonic solution - less solute (more dilute) than the RBC
Result: Hemolysis (RBC swells due to influx of H2O, bursts opens, and dies)
3. Hypertonic solution - more solute (more concentrated) than the RBC
Result: Crenation (shrinking or shriveling due to loss of H2O)
ECF - extracellular fluid (outside the cell)
ICF - intracellular fluid (cytoplasm in the cell)
Facilitated diffusion - membrane protein helps diffusion take place more easily
Na+-K+ pump - requires ATP to go against diffusion
Reason: Low to high concentration
What is the difference between phagocytosis and pinocytosis?
They are both forms of endocytosis.
1. Endocytosis - vesicles fuses and enters the cell
a. Phagocytosis - solid enters the cell (e.g. eating)
b. Pinocytosis - liquid enters the cell (e.g. drinking)
Note: Many WBCs destroy pathogens by phagocytosis.
2. Exocytosis - vesicle fuses and empty the contents out of the cell
Make sure to read Table 3-2 between lectures.
Cell cycle is the life cycle of a cell.
1. Interphase - cell spends most of its time there (living your life)
2. Growth 1 or G1 phase - duplicating organelles and proteins (so both daughter cells
will have a copy of each organelle(s) and protein(s))
3. Synthesis or S phase - duplicating DNA (replication) for both daughter cells to have
the original DNA
histones - proteins that help DNA coil
4. Growth 2 or G2 phase - last minute protein synthesis and duplication of
centrioles/centrosomes for future daughter cells
5. Mitosis or M phase - actual mitosis or cell division that takes place
a. Prophase
b. Metaphase
c. Anaphase
d. Telophase
e. Cytokinesis
Do you remember the details of each of the steps in mitosis?
Note: Not all cells are able to divide (usually missing centrioles/centrosomes).
e.g. RBC or neuron will enter Growth 0 or G0 phase (no growth to prepare for mitosis).
I recommend you watch mitosis or cell division on YouTube.
1.Prophase
a. Nuclear membrane disappears
b. Chromatin coils and condenses into chromosomes
c. Centrioles move to the opposite sides (organize spindle fibers to separate the
chromosomes)
Is that clear in this picture for before and after in "prophase"?
2. Metaphase - chromosomes line in the middle
3. Anaphase - chromosomes are pulled to opposite sides (both daughter cells will receive
identical DNA information)
4. Telophase (reverse of prophase) –
a. Nuclear membrane reappears
b. Chromosomes uncoil and decondense to become chromatin (loose DNa strands)
c. Cytokinesis starts
5. Cytokinesis - "splitting of the cytoplasm" and the cell splits into 2 identical daughter
cells
That is mitosis or cell division!
Does this review help?
I really need you to master the organelles and mitosis in order to proceed forward.
Next week, we will review Ch. 4 - Tissues.
Did the review help?
Ch. 4 – Tissues
Even the cell has a sense of polarity (direction orientation) in space.
apical surface - top (sometimes you will see microvilli or cilia present)
basolateral surface - grounds the cell to the tissue or organ
Cell junctions tie the cells together so they work as a tissue.
If you want to make quilt, is having a bunch of square fabrics a quilt?
No, because you need to sew the squares together?
Same concept - You need to "sew" the cells together
The "stiches" are called "cell junctions".
Two Types of Junctions:
1. Tight junction - cells are tightly glued together (little or no space between cells)
Note: Desmosome = Tight junction
1. Tight junction = Desmosome
a. Spot desmosome - between cells
b. Hemidesmosome - between cell and basement membrane
2. Gap junctions - large gaps (spaces) between cells for molecules or ions to move for
communication
1/2 of the snap button is a circle
2. Gap junction - large spaces that allow molecules to move between cells for communication
Note: The cardiac muscle has "intercalated discs" with many gap junctions for cell communication
(coordinate the heart beat).
Other 1/2 of the snap button is a circle
Hemidesmosome = 1/2 desmosome (from 1 cell)
Spot desmosome = 2 1/2 desmosomes (from 2 cells) snapped together
simple = 1 cell layer
stratified = 2 or more cell layers
Shapes:
1. Squamous - flattened cells
2. Cuboidal - cube or square shaped cells
3. Columnar - tall cells (like a column)
Note: When it comes to stratified layers, look at the apical surface.
Challenge: You need to remember where you find these types of epithelial cells in the
body.
1. Simple squamous
2. Simple cuboidal
3. Simple columnar
4. Stratified squamous
5. Stratified columnar
6. Stratified cuboidal
7. Transitional
8. Pseudostratified
1. Simple squamous - thin, smooth, and materials move easily
e.g. Mesothelia - lining of serous membranes
e.g. Endothelia - lining of blood vessels
e.g. Alveoli - air sacs in the lungs for air exchange
2. Stratified squamous - provides protection (against sharp bones, against sour foods,
etc.)
e.g. Skin surface
e.g. Entry and exit points of the digestive system (do not use these actual words on a
quiz)
This summary is to help you remember that list of mouth, throat, esophagus, etc.
e.g. Vagina
3. Simple cuboidal - limited protection and allows for movement of materials (secretion
or absorption)
e.g. Glands
e.g. Kidney tubules
e.g. Thyroid gland (metabolism)
4. Stratified Cuboidal - protection and movement of materials (secretion and absorption)
e.g. Sweat gland duct
5. Transitional - cells transition in shape or appearance
What does "transition" mean here?
e.g. Urinary bladder or Bladder
What does the bladder do?
Bladder - stores urine
Full bladder - filled with urine and bladder is completely stretched out
Full bladder - looks stratified squamous
Empty bladder (no longer so stretched out) - looks stratified cuboidal/columnar
6. Simple Columnar - protection and movement of materials (secretions and absorption)
e.g. Digestive organs (stomach, intestine, gall bladder)
7. Pseudostratified - looks stratified, but is really simple (1 cell layer)
pseudo - fake
Do you understand that these cells are really 1 cell layer (all touch the basolateral
surface)?
e.g. Respiratory tract (nasal cavity, trachea, bronchi)
e.g. Male reproductive tract
8. Stratified columnar - protection (thickest possible epithelial lining)
e.g. Pharynx (throat)
e.g. Epiglottis - covering of the windpipe
e.g. Mammary glands
e.g. Salivary glands
3 types of glandular secretions:
1. Merocrine - Golgi vesicles contain enzymes, water, or other materials
e.g. Salivary glands - watery saliva
e.g. Merocrine sweat - watery sweat (not really smelly)
2. Apocrine - loss of apical cytoplasm (thicker secretion)
e.g. Mammary gland - milk secretion is thicker
-> First few days is colostrum (mostly antibodies)
--> Afterwards, it is milk, which is thicker than saliva (watery).
So it is apocrine regardless of the quality or state of milk
e.g. Apocrine - thick odorous stinky sweat (Think of underarm or armpit)
3. Holocrine - cell bursts open and releases its entire contents (thickest possible
secretion)
e.g. Sebaceous gland - releases sebum
What is sebum?
oil
This sebum lubricates the skin.
When we talk about the WBCs, specifically "natural killer cells", you will they perform
merocrine secretions.
What is connective tissue proper?
matrix
fibers
The proteins make up the ground substance (matrix).
Collagen makes up 1 of the 3 fibers?
It must have cells!
Tissues are made of cells.
Connective tissue proper is made up of :
1. Cells
2. Fibers
3. Ground substance
Let's through possible types of cells you may see in connective tissue proper.
1. Cells
a. Melanocytes - cells that produce melanin
b. Fixed/free macrophages - type of immune cell that phagocytosis pathogens
c. Plasma cell - activated B cell or B lymphocytes
d. Red blood cell - carries gases
e. Adipocytes - contain lipids or fats
f. Mast cells - release histamine (cause allergies)
g. Fibroblast - cell makes new skin tissue to repair the injury
h. Mesenchymal cell - stem cell
i. Lymphocyte - 1 of the 5 possible WBCs
Do you remember those 5 types of WBCs from A&P 2?
What is that pneumonic?
Never Let Monkeys Eat Bananas
Most common --> Least common
Monkeys = M - Monocytes
Eat = E = Eosinophils
Bananas = B = Basophils
(least common)
Most people have slower metabolism as they grow older.
Connective Tissue Proper
1. Cells
2. Fibers
a. Reticular fibers - network that protects the shape of the organ
b. Elastic fibers - stretchy and can change length or shape easily
c. Collagen - provide strength
(sometimes flexible and stretches)
3. Ground substance - composition is variable
e.g. Fluid connective tissue such as blood
--> Ground substance is mostly water and proteins
vs.
e.g. Solid connective tissue such as bone
--> Ground substance is mostly calcium minerals and some collagen
Dense connective tissue
1. Regular - predictable pattern
e.g. Muscles
e.g. Tendons
e.g. Aponeurosis
What is an aponeurosis?
tendon - shaped like a rope
aponeurosis - flat sheet of tendon
e.g. epicranial aponeurosis
Do you need a picture of it?
Dense Connective Tissue:
1. Regular - muscle, tendon, and aponeurosis
2. Irregular - no determined pattern of fibers or structures inside (dermis and periosteum).
e.g. Deep dermis.
3. Elastic - stretches and made mostly of elastic fibers
e.g. Blood vessel walls
e.g. Ligaments of the spinal column
Blood is made up of:
1. Plasma >50%
a. H2O (> 90%)
b. Proteins.
c. Solutes.
2. Formed elements <50% (mostly RBCs)
What makes up the formed elements?
wbc and platelets
Formed Elements:
1. Red blood cells, RBCs, or erythrocytes99.9% (reason why blood is so red)
erythro - red
cytes - cells
Purpose: Carry O2 and CO2 or just cases
2. White blood cells, WBCs, or leukocytes
leuko - white
cytes - cells
There are 5 types. Never Let Monkeys Eat Bananas.
Purpose: Immunity (fight pathogens and prevent illness)
3. Platelets - cell fragments for blood clotting
Blood clotting = Coagulation = Hemostasis
hemo - blood
stasis - stop
What is the difference between osteocyte and chondrocyte?
Both Yue and Andre are correct!
osteo - bone
chondro - cartilage
Cartilage growth:
1. Interstitial growth - grow wider
2. Appositional growth - grow longer or thicker
I will e-mail you Quiz 1 on Mon 9/20, which will be due next Fri 9/24 at 12 p.m. noon
(day time).
Types of Cartilage:
hyaline cartilage - joints
elastic- ears
fibrocartilage - intervertebral disc
1. Hyaline - most common and found between bones
e.g. Cartilage in the rib cage
e.g. Synovial joints
It is usually found in articulations (joints) of the bone.
Diathrotic = Synovial joints
Are you alright with these 2 words?
e.g. Respiratory system (larynx, trachea, bronchi, and nasal septum)
2. Elastic cartilage - made mostly of elastic fibers
e.g. Epiglottis
e.g. Ear lobe
3. Fibrocartilage - strong cartilage that can support a lot of weight
e.g. Knee pads
e.g. Intervertebral discs
e.g. Pubic symphysis
Bone Anatomy
2. Lacuna - space where the osteocyte lives
3. Canaliculi - smaller passageways wthin the osteon
4. Osteon - smallest unit of bone
Yes, you can find chondroitin sulfate or proteoglycan pills.
vascularity - presence of blood and blood vessels
Types of Membranes:
1.Mucous membrane - secretes mucous
mucous = mucins (proteins) + H2O (water)
e.g. Many organs systems (digestive, respiratory, urinary, and reproductive tracts)
2. Serous membrane - secretes serous fluid or transudate
--> protect the organ and reduce friction within the body cavity
Serous membrane - found in the organ/body cavities and around organs
a. Visceral membrane - surrounds the organ
e.g. Visceral pericardium - membrane around the heart
b. Serous fluid = Transudate
Purpose: Lubricate the membranes and reduce friction of the organ.
c. Parietal membrane - surrounds the organ/body cavity.
e.g. Parietal pericardium (Eastern: heart envelope) - covering around the heart
cavity.
3. Cutaneous membrane – skin
e.g. Sudoriferous (sweat) glands
e.g. Sebaceous glands
4. Synovial membranes - produce synovial fluid
e.g. Knee injury or "water on the knee" is the excess of synovial fluid coming out
***What is fascia?
fascia connects all types of tissues together.
Skin
Fascia
Bones
Fascia
Blood vessels
Fascia
Organs
Let's review the 3 types of muscles:
1. Skeletal - attached to the skeleton (bones)
a. Voluntary - controlled by the brain
(Exception is a reflex)
b. Multinucleated - many nuclei in each cell
c. Striated - striped in appearance due to actin (thin filament) and myosin (thick filament)
Note: muscle cell = muscle fiber
2. Cardiac - heart muscle
a. Involuntary - not controlled by cerebrum (brain)
b. Usually uninucleated - usually has 1 nucleus, but it may have more than 1 nucleus
c. Striated - due to actin and myosin
d. Intercalated discs - made up of gap junctions
What do you think is the purpose of intercalated discs?
cardiac muscle
Yue is correct that the cardiac muscle is most sensitive to time, when it does not work
properly.
This is why the cardiac muscle must communicate all the time to coordinate the
heartbeat.
So intercalated discs are unique to cardiac muscle.
Purpose: Communication
Is that clear?
1. Skeletal - attached to the skeleton (bones) a. Voluntary - controlled by the brain
b. Multinucleated - many nuclei in each cell c. Striated - striped in appearance due to
actin (thin filament) and myosin (thick filament)
2. Cardiac - heart muscle a. Involuntary - not controlled by cerebrum (brain)
b. Usually uninucleated - usually has 1 nucleus, but it may have more than 1 nucleus c.
Striated - due to actin and myosin d. Intercalated discs - made up of gap junctions
3. Smooth - found in respiratory, digestion, urinary, reproductive tracts, and blood vessels
a. Involuntary - not controlled by cerebrum (brain)
b. Uninucleated - 1 nucleus per cell
c. Not striated - looks smooth in appearance!
d. Desmin - intermediate filament (criss-cross and help the muscle to contract)
Do you need a picture of desmin?
Do you have a better understanding of the 3 types of muscles?
Two types of nervous tissue:
1. Neuron - communicates and send signals (action potential) to other cells
2. Neuroglia = Neuroglial cells = Glial cells = Glia - protect and nurture the neurons
The neuroglia does not communciate with other cells!
Why do neurons have long axons?
Reason: These axons allow for longer distance communication between less cells.
Tissue repair after injury:
1. Mast cells release:
a. Histamine - itchy skin at the wound site
b. Heparin - thins out the blood to allow more blood to flow to the surface so more WBCs
can show up
c. Prostaglandins - pain, inflammation, and swelling
2. Phagocytes - engulf pathogens and destory them
Quiz 1 is postponed 1 week later.
I still want to go over quiz format.
Quizzes are on Google forms and have 20 questions (mix of multiple choice and fill ins).
Which of the following cells make scar tissue? D
A. Mast cells
B. Lymphocytes
C. Melanocytes
D. Fibroblasts
You just select the correct answer to get full credit.
Multiple choice is either full credit or no credit.
vs.
Fill in questions have zero credit, partial credit, and full credit options.
The ___________ cells make scar tissue.
1/2 credit = correct answer
1/2 credit = correct spelling and grammar
Student 1: fibroblast --> full credit
(correct answer and correct spelling)
Student 2: fabroblast --> 1/2 credit
(correct answer, but wrong spelling)
Student 3: collagen --> zero credit
(wrong answer)
Is that clear with grading fill in questions?
The computer grades the Google Forms. It grades as full credit or zero credit.
I manually go wrong to check if partial credit may be awarded.
Is that clear or do you have any questions about the quiz format?
Next week, we will start Ch. 5 - Integumentary System
1. Skin
2. Hair
3. Nails
My original plan was to e-mail Quiz 1 today and have you spend 3-4 days to get it in this
Friday, but we will postpone it 1 week.
Cheating policy:
1. Take home QUIZ!
2. Not a take home GROUP ASSIGNMENT!
If 2 students are caught cheating by working together, they both fail the quiz.
The second time it happens, they fail the course.
2021/09/20 Ch 5 Integumentary System
Integumentary System (skin, hair, and nails)
The focus is mostly on skin.
Hair  1 or 2 lecture slides
Nails  1 lecture slide
The rest of the chapter is on skin.
For immunology purposes, the skin block pathogens from entering the body.
** The skin has 3 layers:
1. Epidermis - outer skin.
a. Pores - holes for secretions to come out.
e.g. Sweat or oil.
b. Hair shaft - hair seen on the outside.
2. Dermis - middle layer of skin.
can be divided into 2 layers:
i. Papillary layer - superficial and
ii. Reticular layer - deeper
a. Tactile corpuscle - touch receptor.
b. Sebaceous gland - secretes sebum.
This sebum is a natural lubricant for skin.
c. Arrector pili muscle - contracts to creates goosebumps
What are the 2 main reasons, humans have goosebumps?
(1) Cold - goose bumps appear
(2) Fright or fear - goose bumps will also appear
e.g. Frightened cat looks bigger.
Goose bumps cannot be seen in the cat because of all the fur/hair at the surface.
d. Sweat gland duct Sweat glands or "Sudoriferous glands" - produce sweat.
Purpose: 1. Secrete toxins or wastes and 2. Cool down
e. Hair follicle - body of the hair (not seen unless you pluck the hair out).
f. Lamellated corpuscle - pressure receptor.
g. Nerve fibers - detect pain.
3. Hypodermis or Subcutaneous layer- deeper layer of skin.
e.g. Subcutaneous injection - inject deep into the skin.
a. Fat or adipose tissue - cushioning and insulation.
b. Arteries - red and carry oxygenated blood.
c. Veins - blue and carry deoxygenated blood.
d. Cutaneous plexus - network of arteries and veins, usually you see branched capillaries.
The epidermal ridge and dermal papilla look like 2 sides of the bed foam.
When you see them together, what do they form on the skin?
 Fingerprint - made up of the epidermal ridge and dermal papilla.
Forensics - scientists and lawyers use fingerprints to crack down on criminal cases.
1. Do identical twins have the same fingerprints? NO
2. Does your right thumb and left thumb have the same fingerprint? NO
That is why fingerprints can accurately pin down the person by name.
When you are born in the U.S., all babies have their fingerprint, handprint, footprint, and
toeprints taken and saved into a database.
Question: Why is it when you have a blister, there is no more fingerprint?
Blister - physical abrasion between epidermal ridge and dermal papilla
Result: Disrupt the fingerprint and fluid builds up due to inflammation.
When the blister recovers or goes away, the fingerprint comes back.
** Let's take a look at the epidermis layers.
stratum = 1 layer
strata = more than 1 layer
Two types of skin:
1. Thick skin - contains all 5 strata
and
2. Thin skin - contains 4 strata (missing stratum lucidum).
** Did you learn the pneumonic to remember the sequence of strata in the epidermis?
Textbook pneumonic (deep to superficial):
Buy Some Good Looking Clothes
Buy = B = Basale
Some = S = spinosum (spiny in appearance)
Good = G = granulosum (grainy in appearance)
Looking = L = lucidum (light in color)
Clothes = C = corneum (corny in appearance)
A student suggested one (superficial to deep): Chocolate Loving Girl Seeks Boy.
** What are the 3 factors that affect skin color?
1. Melanin - dark skin pigment (white, black, or brown).
2. Carotene - comes from carrots (orange, peach, beige, etc.)
Carotene comes from carrots, squashes, pumpkins, etc.
3. Dermal circulation - how much blood flow present in the skin.
"American flag"
red, white, and blue in color
a. Red - lots of blood flow
b. White - lack of blood flow (pale)
c. Blue - lack of O2 in the blood (also relates to lack for blow flood)
** Factors that affect skin color:
1. Melanin - light or dark skin color.
2. Carotene - beige, peach, tan, olive color, etc.
3. Dermal circulation - red, white, and blue colors.
#1 and #2 are fairly constant during the day
#1 changes due to sun exposure.
#2 changes due to diet (consumption of lots of carrots).
#3 changes all the time during the day.
Does this all make sense so far?
melanocyte - cells that produce melanin pigment
1. Normal skin color - normal production and expression of melanin.
Or
2. Albino (recessive trait) - not often seen in people, but if they have it, there is no melanin
expression.
People with patches of white skin and half albino and half normal skin color.
**Cleavage lines of the skin - fiber (usually collagen) pattern arrangements in the skin.
Surgeons - cut parallel to the cleavage lines to minimize scarring of tissue.
**No need to study every detail about hair unless you want to become a barber or cosmetology.
What is cosmetology (美容)? The professional skill or practice of beautifying the face, hair, and skin.
Our purposes, we will not study these types of details.
Hair:
1. Root - bottom or base of hair.
2. Follicle - body of the hair.
3. Shaft - head or top of the hair (exposed hair).
Let's about glassy membrane.
When you pluck the hair, sometimes you see something clear and shiny at the root of the hair.
Ever see that?
That is the glassy membrane.
** What is the difference between "sebaceous follicle" and "sebaceous gland"?
1. sebaceous follicle - releases sebum but has No Hair.
vs.
2. sebaceous gland - releases sebum, but hair is present.
** Two types of sweat glands:
1. Apocrine sweat (loss of apical cytoplasm) - thick odorous (bacteria) sweat.
e.g. Arm pit.
e.g. Genitals.
e.g. Areola dark circle region around the nipple.
Bacterial growth on apocrine sweat causes the odor.
2. Merocrine sweat - watery sweat (Golgi vesicle secretions) and is not really smelly.
** The anatomy of the nail :
1. free edge - part of the nail that is clipped off.
2. lateral nail fold - skin region surrounding the lateral edges of the nail.
3. nail body - bulk of the nail structure.
4. lunula - white crescent moon structure at the base of the nail.
Near the root, these vessels may be obscured, leaving a pale crescent. The base of nail is compressed
there (lack of blood flow).
5. proximal nail fold - skin near the base of the nail.
6. eponychium - really the cuticle (can be trimmed or pushed back).
If the nail body is too close to the skin, the nail can dig into the "lateral nail groove". That leads to
"ingrown nails". People with ingrown nails feel a lot of pain.
7. nail bed - skin region (usually pink with blood flow) underneath the nail body
What is the phalanx?
phalanx - bone of the finger.
Question: What is the purpose of having nails?
The nail protects the phalanges.
phalanx - 1 finger bone.
phalanges - 2 more or finger bones.
8. hyponychium - sensitive skin underneath the nail.
9. nail root - base of the nail.
Nail root cannot be seen. The nail bed is under the nail body.
You touch the nail and most likely it is the nail body.
** Receptive field - region of the skin innervated by a nerve or neuron.
Receptive fields are closer together  sensitivity of the skin.
Receptive fields are further apart  less sensitivity in the skin.
Being in the same receptive field will feel like sensory information in the same region.
If you tap receptive field 1 and then tap receptive field 2, the person feels like 2 different areas were
touched.
----------------------------------Experiment #1 - You tap the person on receptive field 1 (left side).
You tap the person on receptive field 1 (right side).
The person will feel it is the same location (same neuron that receives the signal).
Experiment #2 - You tap the person on receptive 1.
You tap the person on receptive field 2.
The person will feel you tapped him in 2 different locations.
The closer the receptive fields, the greater the sensitivity.
The further the receptive fields, the lesser the sensitivity.
High sensitivity regions: Lips, eyelids, tongue, areola, nipples, genital area, fingertips, etc.
Less sensitive (not as sensitive) area for most people: back.
** General senses found in the skin:
(1) tonic - persistent, casual, or annoying.
e.g. Free nerve endings - tonic pain.
e.g. Merkel cells or tactile discs - tonic touch.
Note: Avoid stimulating Merkel cells and tactile discs in a massage.
(2) phasic - on/off, therapeutic, or pleasurable.
e.g. Root hair plexus - phasic hair movement and skin distortion.
Experiment - Move the hair, but do not touch the skin.
You will feel a tingling sensation.
**Notice this on/off sensation.
tonic - persistent, casual, or annoying
e.g. Free nerve endings - tonic pain
phasic - on/off, therapeutic, or pleasurable
e.g. Root hair plexus - phasic hair movement and skin distortion.
1. Free nerve endings - tonic pain.
2. Root hair plexus - phasic hair movement and skin distortions.
3. Merkel cells or Tactile discs - tonic touch.
4. Meissner's corpuscle or Tactile corpuscle - phasic touch.
Notice that #3 and #4 are both touches, but the touch sensation is very different.
5. Ruffini corpuscle - tonic pressure.
e.g. Someone poking you (annoying)
6. Lamellated or Pacinian corpuscle - phasic pressure.
e.g. Massage with the right pressure.
2021/09/27 CH 19 - Blood
** The composition of Whole Blood:
1. Plasma (>50% or >1/2) - mostly water.
a. Water = 92% (>90%).
b. Proteins - structural and functional purposes.
c. Solutes - substances dissolved in the plasma.
solute = smaller amount.
solvent = larger amount.
Solute + Solvent = Solution
e.g. Salt + Water = Salty solution
2. Formed Element (<50% or <1/2).
a. Red blood cells = RBCs = erythrocytes (red cells) - carry gases such as O2 and
CO2.
b. White blood cells = WBCs = leukocytes (white cells) - immunity or to fight
pathogens to prevent disease or illness.
c. Platelets - cell fragments (not whole or complete cells)  blood clotting.
Blood clotting = Coagulation = Hemostasis.
hemo - blood
stasis - stop
Reason for the name of "formed elements" is because platelets are not cells.
**What is the disease called that affects blood clotting?
1. Platelets - blood clotting.
Disease: Hemophilia (sex linked or more common in men).
e.g. Paper cut or a bruise is a very serious issue and if not treated, could lead to
"bleeding to death".
2. White Blood cells - immunity
a. Leukemia- it is an excess of WBCs.
Too many cells  Tumors  Cancer
So, leukemia is a form of "white blood cell cancer".
b. Leukopenia- too few WBCs.
e.g. Radiotherapy - radiation to treat cancer (also kills some healthy WBCs).
e.g. HIV infection - WBC count is low due to HIV attacking these cells.
3. Red blood cells - carry gases.
a. Anemia- too few RBCs (Symptoms - pale white in color).
b. Polycythemia - too many RBCs (not life threatening). That has to do with air
pressure and concentration of O2, but not really with the RBCs.
Polycythemia is usually caused by "blood doping".
Blood doping - inject only RBCs into your body to boost up the levels of RBCs.
Reason: Competitive advantage to carry more O2 in the blood to give you speed or
power.
We can pick up steroids from blood and urine test to check for athletes who are
cheating.
Nowadays, we can check for EPO = erythropoietin (hormone that makes RBCs).
** Whole Blood:
1. Plasma - mostly H2O.
a. H2O = 92%
b. Proteins
i. Albumins - feel like "raw egg whites" that make the plasma thick
ii. Globulins
- Immunoglobulins (Igs) = Antibodies (Abs) - plasma proteins that help with immunity
- Transport globulins - carry substances in the plasma.
Hb = hemoglobin - protein in RBCs that carry gases (We are not doing formed
elements right now. We are focusing on plasma.)
iii. Fibrinogen - plasma protein that eventually becomes fibrin (threads that trap
RBCs to form a blood clot).
c. Solutes - substances dissolved in plasma.
i. Organic Nutrients - carbohydrates, lipids, proteins (amino acids), etc. to make ATP
energy.
Note: Organic means made of C atoms (not being free of hormones or pesticides).
ii. Electrolytes - ions that conduct electricity.
- Cations (+),
e.g. Na+, K+, Ca 2+, Mg 2+
- Anions (-),
e.g. Cl-, HCO3 -, HPO4 2-, and SO4 2HCO3 - = bicarbonate,
HPO4 2- = biphosphate,
SO4 2- = sulfate.
iii. Organic Wastes e.g. Urea or uric acid  Urine
e.g. Creatinine  Waste products of muscle.
e.g. Bilirubin  Breakdown products of blood
e.g. Ammonium ions  Breakdown products of proteins.
2. Formed elements:
a. Platelets - cell fragments from a "megakaryocyte".
b. White blood cells - 5 types from most common to least common
Pneumonic: Never Let Monkeys Eat Bananas
Monkeys = M - Monocytes
Eat = E = Eosinophils
Bananas = B = Basophils
Note: Many WBCs contain multilobed nuclei (or have at least 1 nucleus).
c. Red blood cells - carry gases.
- Biconcave disc shape (to stack up closely together to squeeze through capillaries).
- No nucleus present and most organelles are missing too (Reason: This makes space
to carry more O2 or CO2).
biconcave disc shape bialy
As a result of not having a nucleus and missing many organelles, the RBC life span
is limited.
Average life span of RBC = 120 days
** Anemia- lack of RBCs.
e.g. Sickle-cell anemia - some or all RBCs that are not are biconcave disc (normal
shape).
-Sickle-cell anemia is resistant to malaria.
50% normal RBCs - able to carry gases (but can be attacked by malaria).
50% sickle cell - carry some gases (cannot be attacked by malaria).
*What are the possible reasons for anemia?
1. Too few RBCs, e.g. Sickle-cell anemia.
2. Too few or defective hemoglobin.
Hemoglobin = Hb - contains 4 protein chains (come in pairs).
3. Too few or defective hemes (complicated structure)
4. Lack of Fe 2+ in the diet
You need the Fe 2+ to carry the O2 in the blood.
Typically, iron supplements will help treat anemia.
** -blast  suffix for stem cell
stem cell - mostly found in embryos that can grow into any type of cell, tissue, or organ.
**Red bone marrow  All the formed elements (RBCs, WBCs, and platelets).
**WBCs - 2 classes
1. Granulocytes - look grain in appearance
a. Basophil
b. Eosinophil
c. Neutrophil- (All the -phil WBC cells).
2. Agranulocytes - looks smoother in appearance
a. Monocyte
b. Lymphocyte- (All the -cyte WBC cells).
** Overview on Production of RBCs:
Stem cell (proerythroblast):
5-7 days  Reticulocyte (immature RBC that is missing a nucleus but does not have
biconcave disc shape yet.
Eventually when the biconcave disc shape appears, it will be a mature RBC.
When a RBC nears 120 days in age, it will eventually be filtered out or removed by the
spleen.
Usually, the body will recycle the contents of the old or dying RBC to make a new RBC.
Heme - very complicated chemical structure with Fe 2+ in the middle
Heme - red with Fe 2+
Heme - green when Fe 2+ is missing
Heme with Fe 2+ (red) --> Heme without Fe 2+ (green) --> Biliverdin (green) --> Billirubin
(green) -->
1. Stercobilins (brown) --> feces
2. Urobilins (yellow) --> urine
Think about your bruise...
(1) Bright red/pink - flow of blood.
(2) Purple - mix of red blood (oxygenated) and blue blood (deoxygenated).
(3) Blue - mostly deoxygenated blood (dying blood).
(4) Green - why is it green?! Billirubin – green.
(5) Tan/Brown – stercobilins.
(6) Yellow – urobilins.
Eventually, the bruise disappears.
Do you know the difference between?
1. Antigen (Ag)
and
2. Antibody (Ab) = Immunoglobulin (Ig)
1. Antigen (Ag)
a. Cell surface marker or name tag
e.g. Type A blood - surface antigen is A (name tag is A)
"My name is A."
e.g. Type B blood - surface antigen is B (name tag is B)
"My name is B."
b. Trigger an immune response (activate the antibodies to start fighting)
vs.
2. Antibody (Ab) - plasma proteins (immunoglobulins) that are Y-shaped in structure.
They are light "protein soldiers".
** If you take a Medical Microbiology & Immunology course, you should be able to
explain the difference between:
1. White blood cell
and
2. Antibody
Both help with immunity, but how are they different?
Analogy - Star Wars
Aliens and human fighting --> WBCs (living cells)
Robots or machines that fight --> Antibodies (proteins that fight)
Note: Proteins are molecules, not cells.
** Blood Type:
1. Type A a. A Ag
b. B Ab (also be written as anti-B Ab).
2. Type B -
a. B Ag
b. A Ab (to fight foreign A blood)
3. Type AB a. Both A and B Ags
b. No Abs here (Otherwise, they would fight your own blood)
"Universal acceptor" - accepts any type of blood
Reason: AB can accept A, B, AB (its own), and O blood.
There are no Abs to fight any type of blood.
4. Type O a. No Ags (nothing on the cell surface)
b. Both A and B Abs (Any blood that has A or B Ag is foreign).
"Universal dOnOr" - your blood can be donated to anyone
Type A, B, AB, and O can accept your O blood (nothing on the surface to fight).
However, O blood can only accept O blood (its own type).
Comment: Red Cross goes crazy wanting more O blood donors.
AB is the worst blood for donation.
O blood is the best blood for donation.
 There is also another antigen on the blood surface.
Rh factor
+ = Rh factor
- = No Rh factor
e.g. A+ blood - have A Ag and Rh factor
e.g. A- blood - have A ag, but no Rh factor
These Ags do not affect the quality or function of blood.
Just like having black, brown, or blond hair, does not affect the quality of hair.
Also, Rh factor can be represented by the letter "D".
e.g. AD = A Ag and Rh factor
If you write blood type A, is it...
1. Just A Ag
or
2. A Ag and no Rh factor?
So to avoid confusion, we use the + and - sign to indicated the presence or
absence of Rh factor.
Does that make sense?
Even though O blood is universal dOnOr.
1. O+ = not so universal (some Rh - blood types will reject the Rh factor in O+)
Vs.
2. O- = more of a universal donor (no A or B Ags and no Rh factor).
Bottom picture shows B Abs. That means the person is supposed to be blood
type A.
Question: Why are there B blood cells?!
Blood transfusion gone wrong  Agglutination (blood clumping)  Hemolysis
hemo = blood
lysis - cut open
The B blood will die and be wasted.
Native South American (indigenous tribes living in isolated villages) - 100% O
blood.
If there is a native south American child who is A, B, or AB, that means possible
extramarital affair or unplanned pregnancy.
Nowadays with interracial dating and marriage, the blood types will be more
eventually mixed and distributed.
Blood typing diagnostics: look at clumping or no clumping to determine if there is
agglutination.
** Hemolytic Disease of Newborn
hemo - blood
lytic = lysis - cut open (burst opens and dies)
Most people have Rh factor (good news).
It happens that the mother is Rh -.
1. 1st child is Rh+ (by chance)
The blood exchange does not occur until the "water breaks" and the child is born.
Comments:
a. Childbirth - can be as short as minutes as long as 1-2 days, do you agree?
b. Antibodies - take about 2-3 weeks to form
e.g. Minor cold - maybe the antibodies take 1 week to form.
e.g. Bad flu - maybe the antibodies take 5 weeks to form.
2. Mother is Rh - (by chance)
3. After birth, the mother is exposed to child's Rh+ blood and eventually forms Rh
antibodies.
4. Issue is when the 2nd child is Rh+ because the mother now has Rh antibodies
to fight the fetus' Rh+ blood.
This is a life-threatening situation for the child.
Reason: Stillborn death of a child yet the mother is eating super healthy,
exercising regularly, and no major health issues.
--> Hemolytic disease of newborn.
5. Solution - Inject RhoGAM (anti anti-Rh factor antibody).
In other words, big bully (RhoGAM) is not attacking the small bully (Rh factor Ab)
to protect the fetal blood.
** 5 types of WBCs:
1. Neutrophils - phagocytes (eating cells) or macrophage (big eater) that engulf and
destroy pathogens
e.g.. Pacman - eating stuff.
2. Eosinophils - fights against parasites
Parasite - something that grows in the body, but causes harm, e.g. Worms
Possible sources of infection:
a. Drink contaminated water (with animal feces).
b. Eating raw pork (trichinosis).
3. Basophils - release histamine and cause allergies.
Solution: Take antihistamines (allergy pills).
4. Monocytes - (same function as neutrophils)
- phagocytes and macrophages.
5. Lymphocyte - large nucleus that squeezes cytoplasm to the edges.
Nucleus  brain of cell (lymphocyte is the most intelligent WBC).
We have Ch. 22 - Lymphatics (an entire chapter on it because it is so complicated).
"SPECIFIC" immunity
e.g. Your car key opens the car door, but no others.
So, a chicken pox lymphocyte knows how to fight chicken pox, but no other
diseases.
**Please do not confuse lymphocyte (1 of the 5 WBCs) with leukocyte (all 5 types).
**The phases of hemostasis (blood clotting):
1. Vascular phase - blood vessel constricts (vasoconstriction or vascular spasm) to
reduce the lumen size (area which blood flows) to minimize blood loss
vascular - means blood vessel or blood flow.
2. Platelet phase - platelets pile up to form a "platelet plug" to close open the opening
or wound and temporarily stop the blood loss.
Note: This is not the official blood clot.
Extra chemicals (no need to worry about).
ADP = adenosine diphosphate
PDGF = platelet derived growth factor
3. Coagulation phase - actual blood clotting process.
a. Extrinsic (external) pathway - repair the outside skin or tissues.
b. Intrinsic (internal) pathway - repair the damaged tissue or organs inside the body.
Whether you form the blood clot externally and/or internally, both converge and do the
"common pathway" - actual blood clotting process
Extrinsic & Intrinsic pathways --> Common pathway --> Fibrinogen (plasma protein) -->
Fibrin (sticky threads)
Actual blood clot = Fibrin + Trapped RBCs
?? Do you remember that fibrinogen is 1 of the 3 types of plasma proteins?
**Plasma - mostly H2O
a. H2O = 92%
b. Proteins
i. Albumins - feel like "raw egg whites" that make the plasma thick.
ii. Globulins
- Immunoglobulins (Igs) = Antibodies (Abs) - plasma proteins that help with
immunity.
- Transport globulins - carry substances in the plasma.
iii. Fibrinogens - form the sticky (insoluble) threads that trap RBCs to create the
actual blood clot.
4. Clot retraction - blood clot shrinks and eventually falls off.
Note: During that process, fibroblasts make scar tissue to replace the damaged or
missing skin tissue underneath.
Summary the phases in Hemostasis:
1. Vascular phase
2. Platelet phase
3. Coagulation phase - also know the details
4. Clot retratction.
We know that anemia is more than lack of RBCs (could be Hb, heme, or Fe 2+ issues).
Likewise, hemophilia is not always due to platelet issues.
It turns out many substances (factors) are involved with blood clotting.
1. Platelets.
2. Fibrinogen (plasma protein).
3. 13 different blood clotting factors.
e.g. A person is missing or has a defective blood clotting factor VII (proconvertin).
Then the person will suffer from hemophilia, even if the platelets are normal.
Is that clear that hemophilia is not always a "platelet" issue?
I will e-mail you Quiz 2 on Ch. 5 - Integumentary System and Ch. 19 - Blood after class,
which is due on Sun, Oct 3, at 11:59 p.m. (before midnight).
You have 6.5 days to complete 20 questions.
2021/10/04
Let's review Ch. 3 - Cells & Organelles and Ch. 4 - Tissues (Quiz 1 material).
After the review, I will e-mail you the Medical Microbiology & Immunology Midterm
Exam, which is due on Sun, Oct 10 at 10 p.m. (2 hours before midnight).
Let's review what happens from the nucleus all the way to the Golgi apparatus.
Nucleus - "brain" of the cell where DNA is made
Nucleolus - makes RNA (copy of DNA)
Do you understand the difference between DNA and RNA?
DNA = deoxyribonucleic acid (original genetic information) that never leaves the nucleus
RNA = ribonucleic acid (copy of DNA) and may leave the nucleus through the nuclear
pores
Reason: The information from RNA can be used to make proteins.
***Let's review the types of reactions in the cell:
A. Replication (nucleus): DNA --> DNA That takes place during cell division (mitosis).
B. Transcription (nucleolus): DNA --> RNA The RNA may leave the nucleus through the
nuclear pores and enter the cytoplasm.
C. Translation (protein synthesis in the cytoplasm): RNA --> Proteins
***Ribosomes (fixed and free)
a. Free ribosomes - floating around in the cytoplasm (look like tiny dark circles)
b. Fixed ribosomes - attached to the ER and become RER (rough endoplasmic reticulum)
*** The proteins made by free and fixed ribosomes enter the RER and leave and enter the
cis face of Golgi complex.
What does the Golgi apparatus do here? stores and packs products
1. Lipoprotein = lipid + protein
2. Glycolipid = carbohydrate + lipid
3. Phospholipid = phosphate + lipid
4. Enzymes - digestive to form lysosomes or neutralizing (toxins) to form peroxisomes.
The Golgi apparatus has the ability to form a few of these organelles.
Outcomes of the Golgi apparatus:
1. Create new organelles, e.g. Lysosome or peroxisome.
2. Exocytosis - release vesicles out of the cell.
3. Membrane renewal - nothing inside the vesicle and the vesicle fuses with the cell
membrane to make the cell larger.
Let's focus on #1 outcome - Lysosome formation
Note: Primary lysosome - mean newly formed lysosome or a lysosome with nothing inside
other than digestive enzymes
1. Lysosome - breakdown damaged organelles.
2. Lysosome - digesting nutrients or destroying pathogens.
3. Lysosome - Autolysis (self destruction) of cell by releasing digestive enzymes.
*** What is the difference between chromatin and chromosome?
1. Chromatin - loose DNA (readily available like during interphase)
vs.
2. Chromosome - compact DNA (easily separated as 2 copies to be given to 2 daughter
cells after mitosis).
*** Let's review the steps of Translation (protein synthesis).
1. Initiation - bring mRNA, tRNA with its AA, and rRNA together
AA = amino acid
2. Elongation - form peptide bond between 2 amino acids (make the protein chain longer).
3. Translocation - move 1 codon (3 bases or a triplet on mRNA) over to bring in another
tRNA with an AA
Note: Steps 2 and 3 repeat until the cell is done adding amino acids to the protein
(polypeptide) chain.
Review: codon = triplet on mRNA vs. anticodon = triplet on tRNA
4. Termination - protein synthesis stops and the mRNA, tRNA, and rRNA disassemble, and
release protein chain.
*** Let's review the cell cycle.
1. Interphase - cell living its life and spends most of its time there
2. Growth 1 or G1 phase - cell duplicates organelles and proteins (to prepare for cell division)
3. Synthesis or S phase - cell duplicates DNA (replication) and histones (DNA proteins)
Reason: Both daughter cells need the original DNA.
4. Growth 2 or G2 phase - cell does last minute protein synthesis and duplicates the centrioles
5. Mitosis or M phase - cell actually divides here through a series of steps
a. Prophase
b. Metaphse
c. Anaphase
d. Telophase
6. Cytokinesis - splitting of the cytoplasm to form into 2 identical daughter cells
Note: Some cells remain indefinitely (could be temporary or permanent) where they never divide and
stay in Growth 0 or G0 stage.
Reason: Possible reason is the cell does not have centrioles (needed for cell division).
e.g. RBCs - missing centrioles and cannot divide
Do you have any particular questions about the different stages of mitosis?
I feel that videos really help to see the chromosome movement.
*** What are the 2 types of cell junctions?
1. Tight junction = Desmosome
a. Spot desmosome - between cells
b. Hemidesmosome - between cell and basement membrane.
2. Gap junction - large spaces that allow molecules to move between cells for
communication
Note: The cardiac muscle has "intercalated discs" with many gap junctions for cell
communication (coordinate the heart beat).
*** Different types of tissues:
1. Connective tissue - connect different layers and structures together
e.g. Fascia - connects the skin to the muscles to the bones to the organs
2. Endothelial tissue - inner lining of organs or blood vessels.
3. Mesothelia tissue - lining or serous membranes (visceral and parietal membranes)
a. Visceral membrane - around the organ
b. Parietal membrane - around the organ/body cavity.
4. Epithelial tissue - covering of the surfaces of the organs.
Classifying epithelia tissue:
simple (1 cell layer) vs. stratified (2 or more cell layers OR more than 1 cell layer)
You may classify based on shape or appearance.
1. squamous - flattened cells
2. cuboidal - cube or square shaped cells
3. columnar - tall cells.
**Let's do some trivia questions on the 3 types of muscles.
1. Intercalated discs - What is the muscle? cardiac muscle
2. Desmin - What muscle here? desmin - intermediate filaments that criss cross like a
mesh bag to squeeze smooth muscle (Remember that analogy about ham in a mesh bag?)
 smooth muscle
3. Multinucleated - What muscle here? Skeletal muscle (Reason: myoblast fusions)
4. Usually uninucleated - What muscle is it? cardiac muscle
5. No striations - What muscle is it? no stripes so it is smooth in appearance  smooth
muscle
6. Voluntary - What muscle here? only 1 is voluntary  skeletal muscle.
** Let's review nervous tissue.
1. Neuron - cell body and dendrites that send sensory information to other cells
2. Neuroglia or Glia - protects, nurtures, and provides for the neurons.
Only the neurons are involved with cell communication (through the axon - long extended
part of the cell).
** Let's just review wound healing:
1. Inflammation - redness, swelling, and pain.
Redness - increased blood flow
Swelling - extra fluids leaking out or WBCs and other cells present
Pain - cause prostaglandins
Note: heparin - allows for smooth blood flow
histamine - allergic response --> itchy skin surface near or at the wound site
2. Regeneration - fibroblasts grow skin tissue back to replace damaged or lost skin
tissue.
Note: If the injury is serious (e.g. Bullet wound), then extra scar tissue forms to create a
"scar".
2021/10/11 Ch 23 Respiratory System

The anatomy of the respiratory system:
1. Dorsum nasi - body of the nose
This is usually in reference to the entire nose or maybe just the "bridge of the nose".
2. Apex - tip of the nose.
3. External nares - external nostrils (2 of them) for breathing
4. Nasal cartilages - made up mostly of hyaline cartilage

There are 2 possible ways to breathe in air:
1. Nose
2. Mouth
Which is the preferred way to breathe and why?
Nose - nose hairs may filter out the dirt, debris, and bugs.
The second reason is the mucous inside helps filter and clean the air too.
The third reason is that breathing through the mouth causes dryness and sometimes
greater chance of throat infection.

What is the purpose of the nasal conchae?
 Nasal conchae - increase surface area for mucous to filter, moisten, and warm up
the air before reaching the lungs.
1. Filtering of air - mucous is stick and will trap dirt, debris, bugs, and sometimes
pathogens.
2. Moistening the air - mucous is wet compared to the dry air.
3. Warming up the air - mucous is at body temperature (37o C or 98.6 oF) vs. air
is usually at room temperature (25o C or 77o F).

The 3 paired nasal conchae have different purposes:
1. Superior nasal conchae -olfaction.
2. Middle nasal conchae – breathing.
3. Inferior nasal conchae – breathing.
**sniff - shoot air upwards to reach the superior nasal conchae.
The bottom 2 (inferior and middle nasal conchae) are just for breathing.

Structures of the Upper respiratory system:
1.Sinus - empty space or chamber within the bone
e.g. Facial sinuses - lighten the bonds
If too much mucous accumulates in the sinuses, we say our sinuses are "clogged".
Solution: Blow your nose to get rid of excess mucous.
(1) Best to spit out phlegm - fastest way to get rid of dirty mucous.
(2) The other alternative is to swallow it and let the HCl acids in the stomach kill
the pathogens or dirty phlegm.
2. Pharynx - throat (shared by the respiratory and digestive systems).
a. Breathing - air passes through the pharynx.
b. Eating - food passes through the pharynx.

Air flow direction:
Nose/mouth  Pharynx (throat)  Larynx (windpipe)  Trachea  Primary (1o)
Bronchi –branchesSecondary (2o) Bronchi --branches again Tertiary (3o) Bronchi 
Bronchioles (no cartilage here)  Alveoli (air sacs in the lungs).
3. Larynx - vocal cords are present that produce sound.
e.g. Laryngitis - inflammation of the larynx
(**Notice the person can barely speak and their voice is hoarse or barely audible.)
Vocal fold = True vocal cord - structure that vibrates to produce sound.
4. Epiglottis - elastic cartilage that covers the larynx (windpipe) to prevent water and
food from entering
Choking - when food or water enters the windpipe.
Coughing - natural reflex to dislodge or move water or solids out of the windpipe.
 Difference between Epiglottis and Glottis:
Analogy (comparison):
Think of the trash can like the one you see in Sesame Street (Oscar the Grouch).
Epiglottis  trash can lid
Glottis  opening the trash bag (can also close it)
You really need to do both in the suburbs.
The racoons rummage through the trash.
When the glottis closes, it stops food from entering the larynx.
However, water can still seep through.
Think of trying to contain or hold the water between your fingers.
As a precaution, the epiglottis covers the glottis to block liquids from entering the
larynx.
5. Esophagus: "food tube" where food reaches the stomach.

The Respiratory Epithelium:
The surface of many parts of the respiratory tract looks like "shag carpet".
Each extension is really a cilium.
1. cilium (s.) or cilia (pl.) - finger like extensions that move material across the
surface.
They sweep the mucous from the lungs upwards to the pharynx.
**Acupuncture: analyze the quality, texture, or color of phlegm
(1) mucous - inside the body.
(2) phlegm - mucous in the throat to be coughed or spit out.
a. Clear or off white – normal.
b. Yellow/green - possible sign of infection bacterial or viral infection.
c. Red - bleeding - need to monitor it and if it does not stop, you need to see a
doctor.
 When does the cilia stop sweeping the mucous upwards to the pharynx?
mucous = mucin protein + water
Answer: Smoking
The nicotine (stimulant) stuns the ciliated cells, so they stop moving the mucous
upwards.
The tar in the cigarette normally would be swept upwards to be spit out.
The nicotine stops that, and the tar builds up in the lungs.
Nicotine gives the person a "high feeling" or state of "euphoria" so smoking
becomes very addictive.
The tar stops the functions of many cells in the lungs.
Smokers have a much greater chance of dying from "lung cancer" than the average
population.
 Comparison of 2 Lungs:
1. Right Lung:
(1) 3 lobes
(2) wider
(3) shorter
What organ is below the diaphragm on the right side?
LV = liver
The liver squeezes and pushes the right lung upwards.
2. Left Lung:
(1) 2 lobes
(2) Narrower
(3) Longer
 What organ is located between the 2 lungs, but is more to the left side?
HT = heart
The heart is squeezing the left lung by making it narrower and longer in shape.
This is my pneumonic for remembering the # of lobes for the lungs.
Right side:
1.Heart - 3 valves --> tricuspid valve.
2.Lung - 3 lobes
Notice the "3"s match on the right side.
Left side:
1. Heart - 2 valves --> bicuspid valve
2. Lung - 2 lobes
Notice the "2"s match on the left side.

The gross anatomy of the lungs:
The coloring of blood vessels associated with the lungs have many exceptions:
1. Pulmonary artery - blue or deoxygenated (blood is going to the lungs to pick up
oxygen).
2. Pulmonary veins - red or oxygenated (blood just picked up oxygen from the lungs).
In general (other than exceptions for the pulmonary arteries and veins).
red  artery
blue  vein
yellow  nerve
green  lymphatics (part of immune system)

What is the purpose of the mediastinum in the thorax?
Mediastinum "tissue organizer".
- wraps around different organs and structures to keep them organized and
compartmentalized.
e.g. The mediastinum can organize and separate the aorta, vena cava, esophagus,
thymus, heart, lungs, etc. from each other into compartments.

1.
2.
3.
4.
The Anatomy of the Larynx:
Epiglottis - elastic cartilage that covers the glottis (opening).
Thyroid cartilage - largest cartilage in the respiratory tract.
Laryngeal prominence (found on thyroid cartilage) - protrusion (something that
sticks out) --> "Adam's apple".
Men  larger Adam's apple.
Women  smaller (or not noticeable) Adam's apple.
Why do men on average have larger Adam's apple?
It is true that testosterone can enlarge the vocal cords, which cause the laryngeal
prominence (Adam's apple) to stick out or protrude more on the neck.
Bass - thick long strings  low pitch.
Violin - thin shorter strings high pitch.
Tracheal cartilage - C or U shaped cartilage rings
Why does the tracheal cartilage not make the full circle and entirely wrap around
the trachea?
What is located behind the trachea? Esophagus - located behind the trachea.
Ever swallow a very large piece of food before?
You feel this lump of food move down the esophagus.
So, the esophagus must expand to accommodate the size of the food particle or
piece.
The posterior side of the trachea is "trachealis muscle". There is no cartilage on
the posterior side.
Cartilage  more rigid (keeps the respiratory tract open).
Muscle - can expand and contract easily.
**To have C or U shaped tracheal cartilage rings where the posterior side is trachealis
muscle to allow for possible expansion of the esophagus should there be a large food
particle moving down towards the stomach.
5. Vocal ligament = Vocal fold = True vocal cord - actual vocal cords that vibrate and
produce SOUND.
6. Vestibular ligament = Vestibular fold = False vocal cord - look like the true vocal
cord, but they Do Not produce sound!
Fig 23-5. Notice the white lines next to the glottis are the true vocal cords while the
gray lateral tissues are false vocal cords look like vocal cords, but do not produce
sound.

3 possible scenarios:
1. Completely open larynx (windpipe)  glottis is open, and epiglottis is not
covering glottis.
2. Partially closed larynx  glottis is closed, but epiglottis is not covering it.
Result: Food will not enter, but liquids may still seep into the windpipe.
3. Completed closed larynx - glottis is closed and epiglottis is covering it.

Air flow direction:
Nose/mouth  Pharynx (throat)  Larynx (windpipe)  Trachea  Primary (1o)
Bronchi –branchesSecondary (2o) Bronchi --branches again Tertiary (3o)
Bronchi  Bronchioles (no cartilage here)  Alveoli (air sacs in the lungs).
**Notice that the bronchi enter the lungs.
Any issue with the bronchi usually means a more serious respiratory infection.
e.g. Bronchitis - inflammation of the bronchi may result in painful breathing (lungs are
also affected).
Once we become 2o bronchi or 3o bronchi, notice there are no more C or U shaped
cartilage rings. They are actually "cartilage plates" that keep the bronchi open.
The bronchioles have no cartilage and can easily close the air passageways.
**Pathology:
Asthma - bronchiole constriction (no cartilage to keep the bronchioles open) and this
involves smooth muscle (not under our voluntary control).
People who have asthma tend to be scared to exercise or do aerobic activity.
Irony: The way to treat or reduce the symptoms of asthma is to keep doing aerobic
activity.
e.g. Slow walk for a few blocks.
Eventually, you start jogging, then running, and then take aerobics gym classes.
** The alveoli with no cartilage has similar problems like the bronchioles.
Pathology: Emphysema or respiratory distress syndrome  difficulty in getting air into
the alveoli (air sacs).
Notice the cross section of the alveoli looks like the cross section of a honeycomb.

Fig 23-1bc Alveolar Organization (close view of the alveoli):
1. elastic fibers - allows the alveoli to contract and expand in response to breathing.
2. capillaries - tiny blood vessels for gas (both O2 and CO2) exchange.
3. alveolar macrophages - general immunity for WBCs to engulf and destroy
pathogens.

There are 2 types of pneumocytes:
1. Pneumocyte I - allows for gas exchange in the alveoli.
2. Pneumocyte II - produces surfactant to prevent alveolar collapse.
What is a surfactant?
Surfactant - bubbly substance
e.g. Dishwashing liquid.
e.g. Laundry detergent.
e.g. Liquid hand soap.
All are naturally bubbly substances.
The alveolar membranes are so thin that they stick together like 2 pieces of Saran wrap.
"alveolar collapse" - alveolar membranes together and causes the alveoli (air sac) to
collapse or close up so air can no longer enter
Result: Gasping for air --> difficulty for breathing
Analogy:
Imagine you have 2 pieces of Saran wrap and you add 1 drop of dishwashing liquid
between the 2 layers.
The static (I believe Meng was referring to surface tension) is gone where the 2 Saran
wraps glide among each other, but do not stick to each other.
Result: The surfactant allows the air to flow in the alveoli because the alveolar
membranes will not be stuck together.
That is the purpose of the Pneumocyte II is to create that surfactant.
COVID-19 causes so much lung tissue damage that it is like having 60% working lungs.

Two types of Respiration:
1. External respiration - gas exchange between the lungs and RBCs
Note: The lungs do not move around the body to provide O2 other cells and tissues.
So, the RBCs are like the messengers that deliver the O2 and pick up the CO2 from
tissues.
External  Lungs is considered to be an "external organ".
2. Internal respiration - gas exchange between the RBCs and tissues.
Note: This is respiration internally or inside the body in terms of gas exchange.

Gas Pressure and Volume Relationships:
 Boyle's Law - pressure and volume are inversely related to each other.
1. pressure - how many particle collisions against the surface of the container.
e.g. Crowded - more collisions
e.g. Sparse - less collisions
2. volume - how much space it takes up.
Base on the Boyle’s Law:
That means P = pressure and V = volume are opposites like a see-saw.
If P goes up, V goes down.
or
If P goes down, V goes up
**Fig 23-13.
(a) Smaller volume  You end up with larger pressure. V down and P up.
(b) Larger volume  You end up with smaller pressure. V up and P down
*Later we will use the volume of the lungs (instead of the box).
We will also talk about the pressure of the lungs (instead of the box).

The movement of the ribcage is like a "bucket handle".
Inspire = Inhale - notice the rib cage moves up and outward.
Expire = Exhale - notice the rib cage moves down and inward.

State of Lungs:
1. Rest: P outside air = P inside lungs.
2. Inhalation: P outside air > P inside lungs.
Observation: It is like the outside air pushing into your lungs.
or
It is like the inside air sucking in the air into the lungs.
**Think about the volume of the lungs.
Does the lung volume get larger or smaller when inhaling air? Larger
So, if V goes up, then P in the lungs go down.
3. Exhalation: P outside air < P inside lungs
Observation: It is like the inside air pushing air out of the lungs.
or
It is the outside air sucking air out of the lungs.
You will notice in exhalation; the lung volume goes down and the pressure
increases inside the lungs.
There was actually a real license exam question on spirometer.
Question: What organ does the spirometer pertain to?
Spirometer - machine that measure air flow of the lungs either by:
1. Volume of air in and out of the lungs.
or
2. Changes of air pressure in the lungs.
You are supposed to have taken HS 300 Surface Anatomy before taking HS 401 Medical
Microbiology and Immunology. You should have basic understanding of muscles.

Two types of breathing:
1. Passive or quiet breathing - breathing in and out in daily life (not noisy or
noticeable).
2. Active breathing - tends to be rushed and noisier.
e.g. After a strenuous exercise workout.
e.g. Running as fast as you can to catch the train or bus before it leaves.
Whether you are active or passive breathing, you must use the 2 primary muscles:
A. Diaphragm:
B. External intercostals - between the ribs and located externally (pull rib cage up
and outward)
Think of the diaphragm as a trampoline.
--You jump onto it and the trampoline flattens out. (This is like diaphragm
contraction).
vs.
--You jump off the trampoline, it goes right up into a dome shape (This is like
diaphragm relaxation).
**I will show you my study guide for Quiz 3. Do you see Quiz 3 study guide for Ch. 23?
Let's look at Active Breathing. You still use the same muscles in the same way for
Passive Breathing.
Issue: You need more speed and force to do active breathing.
 The accessory muscles for active breathing inhalation all attach to the ribs (usually
high in position).
So, the movement is up and outwards of the rib cage for the inhalation accessory
muscles.
 The accessory muscles for active breathing exhalation all attach to the ribs
(usually low or behind in position).
So, the movement is down and inwards of the rib cage for the exhalation
accessory muscles.
***Accessory muscles are only used in active breathing when there is need strength and
speed in breathing.
Passive breathing can easily be handled by 2 primary muscles of: 1. diaphragm and 2.
external intercostals.

Make sure you sort out:
1. Passive inhalation.
2. Passive exhalation.
3. Active inhalation.
4. Active exhalation.

The flow of air (O2 and CO2) between the RBCs and alveoli is due to diffusion.
Diffusion - movement of materials from high to low concentration.

Fig 23-28 basically states it is never too late to quit smoking.
Notice that when you quit smoking at age of 45, you can increase your life span by
about 8 years.
Let's say you quit smoking when you are 65, you increase your life span by by 4-5 years.
A lot of people smoke to deal with stress.
The best way is to eat healthy, exercise, meditate/yoga, and also time management.
We are done with Ch. 23 - Respiration.
10/18/2021 Chapter 22
＊Blood vessels - transports mostly RBCs and also WBCs and platelets
＊Lymphatic vessels - transport WBCs, but mostly lymphocytes
＊Lymphatic system - organ system that deals with immunity (WBCs such as
lymphocytes)
 Lymphocytes  specific immunity.
1. T lymphocytes/cells  come from Thymus (as a fetus) T for thymus
2. B lymphocytes/cells  come from Bone marrowB for bone
3. NK cells = Natural killer cells.  also comes from Bone marrow.
Later, we will focus on these 3 types of lymphocytes.
 Lymphatic system:
1. Lymphocytes (3 types)
2. Lymphatic vessels - transport mostly lymphocytes and lymph
3. Lymph - fluid of the lymphatic system
4. Lymph nodes - enlarged regions of the lymphatic vessels
5. Lymphoid tissue and organs - tonsil, thymus, spleen, etc.
 Lymph nodes:
What is the purpose of the lymph nodes?
1. Produce lymphocytes (T cells, B cells, and NK cells).
2. Communication center - alerts the lymphocytes of possible pathogens or infections to
prepare and fight them.
"Rest stop" - driving long distances and you use the rest stop to get something to eat,
rest, go to the bathroom, and read the NEWSPAPERS
So going back to Kaitlyn's comment, the lymph node can become active or swollen when
there is an infection.
Enlarged lymph node - active lymph node busy producing lymphocytes to fight a
pathogen.
e.g. Swollen neck lymph nodes possible sign of throat infection.
There are many lymph nodes in the body.
1. Cervical.
2. Axillary.
3. Mammary.
4. Lumbar.
5. Pelvic.
6. Inguinal.
 The fetus makes T cells in the thymus.
Fetus - child in the mother's womb that is not born yet.
Do you understand the difference between thymus and thyroid based on function and
location?
*Thymus:
1. Located in the thorax (chest) and sits above the heart.
2. Plays a role in immunity for the fetus (making T lymphocytes).
3. Once a child is born, the thymus is no longer used to make T cells.
4. Lymph nodes in the newborn child and adult make the T cells instead.
vs.
*Thyroid - metabolism (not shown here).
1. Located inside the cervical or neck region.
2. Does not a direct role in immunity, but rather focus on metabolism (chemical
reactions of the cells).
 The major lymphatic vessels names:
Lymphatics - immune system.
lymphatic vessel = lymphatic duct.
Names of lymphatic vessels/ducts
1. Right lymphatic duct.
2. Left lymphatic duct = Thoracic duct.
Reason: Most of the lymph fluid drainage is in the left lymphatic duct (mostly on the left
side of the chest).
You will notice that more than 3/4 of the lymph drainage is into the thoracic duct = left
lymphatic duct
Possible reasons (based on my observations):
1. Heart is located on the left side - most of the extra fluids end up in the heart.
2. Brachiocephalic trunk/vessel - only on the right side (takes up space) so maybe the
allocation of lymph fluids would end up on the left side of the chest anyway.
 Review A&P 2: Ch. 21 - Blood vessels
Cisterna chyli - large lymph node found in the abdomen that drains most of the lymph
from the right and left legs up to the abdomen and into the chest.
Lymph (legs)  Cisterna chyli (abdomen)  Thoracic duct = Left lymphatic duct
Heart.
 Lymphoid tissues and organs:
1. Tonsil - lymphoid tissue located in the neck/throat region. Keep them because they
contain lymphocytes and help reduce chances of throat infections.
contains lymphocytes that fight pathogens in the food and air.
IN the past, it was a general practice to have lymph nodes removed.
Have you heard of this before?
Why remove your first life of defense against pathogens in the air or food?
Reason: Doctors and scientists did not understand what was the purpose of having
tonsils.
Leave these tonsils alone!
Nowadays, no one actively goes to have the tonsils removed.
Exception: If your tonsils are inflamed or infected and the pathogens could spread
elsewhere, then you should remove the tonsils.
2. Thymus - make T lymphocytes as a fetus.
3. Spleen - filter blood.
Remove dirt, debris, or pathogens.
Remove dead cells (dying RBCs).
4. MALT = mucosa-associated lymphoid tissue
"lazy way" to call the lymphoid tissue found in many organ systems a generic name.
e.g. Digestive, respiratory, urinary, reproductive organs system lymphoid tissue all
called MALT.
5. Appendix - lymphoid tissue that contains lymphocytes to clear waste products from
feces in the intestines.
This was a real massage license exam question:
Where is the appendix located?
A. Small intestine
B. Large intestine
C. Between small and large intestines
D. Depends on the person
The correct answer is D.
Every person has a different coiling pattern of small and large intestines.
So, the appendix is generally in the lower right abdomen of people.
Pathology: Appendicitis - inflammation of the appendix may be life threatening.
red - artery
blue - vein
green - lymphatic vessel
yellow - nerve
Both lymphatic vessels and veins contain valves to prevent backflow of fluids.
e.g. Blood vessel valve- prevents backflow of blood
e.g. Lymphatic valve - prevents backflow of lymph
Most of the emphasis on exams is on the names of arteries and veins, but not so much
on lymphatic vessels.
 Lymphatic vessels:
1. Right lymphatic duct.
2. Left lymphatic duct = Thoracic duct.
 3 types of lymphocytes:
1. T lymphocytes = T cells = CD 8 cells = CD 8+ cells
or CD 4 cells = CD 4+ cells
How do you know what to call them?
If you know it is a T cell, just call it...
"T cell" or "T lymphocyte"
If you know it is a "cytotoxic T cell", then you may call it "CD 8 or CD 8+ cell".
If you know it is a "helper T cell", then you can call it "CD 4 or CD 4+ cell".
a. Cytotoxic T cells = CD 8 cells - attack foreign cells (e.g. bacteria) or infected body cells
(e.g. infected with a virus)
- destroy pathogens (attack the bacteria)
- kill infected body cells because these infected cells will continue to spread the
infection in the body
cyto = cell
toxic = poisonous
Do you understand cytotoxic T cells?
Sometimes we think of cytotoxic T cells as "foot soldiers"
 3 Types of Lymphocytes:
1. T cells
a. Cytotoxic T cells = CD 8 cells - attack foreign cells (e.g. bacteria) and infected body
cells (e.g. infected by a virus).
b. Helper T cells = CD 4 cells - activate both T cells and B cells.
Analogy: Helper T cells are like the 'general' or 'commander' of the army.
Which virus attacks helper T cells? HIV acquired immunodeficiency syndrome
What does HIV stand for? acquired - caught the HIV usually through sex or possibly
through drug needle use
acquired - caught the HIV usually through sex or possibly through drug needle use
immunodeficiency - immune system is not working too well or has shut down
syndrome - symptoms of a disease
HIV is the virus that attacks helper T cells or CD 4 cells.
It is like losing the "general" of the army.
You end up with a bunch of WBCs floating around, not know what to do or how to fight
any pathogen or any disease.
The person does not die of HIV itself, but through the complications of the immune
system no longer working.
e.g. A person with AIDS could even die of a common cold.
e.g. Mold growing in the lungs (not normally seen in people with normal immune
system)
If you read articles about AIDS, most of them talk about CD 4 cell count being low.
I actually do not remember the exact number.
Other factors that affect the immune system (besides HIV)...
1. Radiotherapy - use of radiation to treat cancer (WBC count may be low).
2. Depression or stress - may also affect the immune system.
3 types of lymphocytes:
1. T cells
a. Cytotoxic T cells = CD 8 cells
b. Helper T cells = CD 4 cells - activate both T and B cells
c. Suppressor T cells - suppress the immune system
Why or when would you want to suppress the immune system?
Yue Rong
1:07 PM
transplant
pregnancy rh
Yue is correct in that sense that doctors administer immunosuppressant drugs for
anaphylaxis, organ transplants, and hemolytic disease of the newborn child.
However, why do the suppressor T cells suppress the immune system?
Yue Rong
1:09 PM
so you dont have bigger reaction that cause peoblem
like covid 19
Yue is on the right track.
That is also true about COVID-19.
Let's talk about COVID-19.
What does COVID-19 stand for?
CO = coronavirus
The spikes of the virus stick out like rays of the sun --> "corona"
Correction: CO = corona
VI = virus
D = disease
19 = 2019
Both HIV and COVID-19 attack the immune system.
HIV is a direct attack.
COVID-19 is an indirect attack. It causes the immune system to attack its own
tissues and organs.
Complications of COVID-19 include (but not limited to):
1. Lung damage
2. Kidney damage
3. Heart damage
4. Brain damage
5. Blood clots --> stroke and heart attack
i saw it line up to go in the hospital in 2am morning
like 2 blocks
I think right now more than 700,000 of Americans have died from COVID-19.
However, many people who died of COVID-19 at home were not counted in that
700,000 count.
Any questions or comments so far?
Last year, everyone in NYC or NYS had to stay home for about 90 days.
Some claim it will never end, mainly because Americans tend to be selfish or selfcentered.
International travel really spreads COVID-19 all over the world.
Suppressor T cells - suppress the immune system is because the WBCs have won
the war
e.g. You just recovered from a cold.
Why keep all the WBCs active and fighting when you already won?
3 types of lymphocytes:
1. T cells
a. Cytotoxic Cells = CD 8 cells
b. Helper T cells = CD 4 cells
c. Suppressor T cells
d. Memory T cells
What is the purpose of a memory T cell?
memory T cells - take notes and remember how to fight that particular pathogen
so that in the future if exposed to the same pathogen, the body knows how to
fight it
Analogy: Have you noticed that studying for Quiz 1 or 2 is a lot of work (new
material)?
vs.
When you study for a Midterm, the information is mostly all review. So it is easier
to pick up on the details or relearn that information again.
Sometimes you still need booster shots because the immune system (memory T
cells) over time can forget the pathogen.
e.g. Tetanus booster shot - get it every 10 years
There is talk about COVID-19 booster shots because even after the 2nd
vaccination, the body over several months starts to forget how to fight COVID.
Also, the COVID-19 is mutating so fast that the current vaccine only works against
alpha variant (from 2019-2020), but not really on on the delta variant.
That is why in the news many fully vaccinated people not wearing masks are dying
of COVID-19.
Pandemic - best to be fully vaccinate and wear masks at all time
We covered T cells. Now let's talk about B cells.
Most of the lymphocytes are T cells, but a small majority are B cells and NK cells.
B Lymphocytes/cells --> Plasma cells --> Antibodies
B lymphocytes - made in the "b"one marrow
plasma cells - activated B cells with lots of RER
RER = rough endoplasmic reticulum
What does the RER make here?
These proteins become immunoglobulins (Igs) = antibodies (Abs).
Where do you find these Igs?
You find Igs in the blood plasma.
What are the 3 components of plasma?
Albumin is made of proteins.
I will do a quick review on blood.
Whole Blood
1. Plasma > 50%
a. H2O = 92% (mostly water)
b. Proteins - albumins, globulins, and fibrinogens
c. Solutes - nutrients, electrolytes, wastes
2. Formed elements < 50%
a. Red blood cells (RBCs) = erythrocytes = 99.9% (999 out of 1,000 formed
elements)
b. White blood cells (WBCs) = leukocytes
c. Platelets - cell fragments for blood clotting
Does this sound familiar?
Look at plasma proteins:
A. Albumins - make plasma thicker like "raw egg whites" in texture
B. Globulins - transport globulins (carry substances in the blood) and
immunoglobulins (antibodies)
So going back to that original question, these immunoglobulins come from
"plasma proteins".
C. Fibrinogens - blood clotting
Is it clear that when we talk about B cells, we are using plasma cells' RER to make
plasma proteins called immunoglobulins (Igs) = antibodies (Abs)?
B cells --> Plasma cells --> Antibodies
Let's talk about NK cells.
NK (natural killer) cells - attack cells infected with a virus or cancer cells
1. Some viral infected cells become cancer cells.
e.g. HPV
What does HPV stand for?
HPV = human papilloma virus - sexually transmitted disease
Why is a yeast infection (often from sex) not considered to be an STD?
Because yeast infections can come from the gut?
Kaitlin is correct that yeast infections can be for other reason, other than sex.
HPV - many of the viral infected cells have the potential to become cancer cells
HPV infection --> uterine, ovarian, or cervical cancer
cervical = cervix (opening or entry point) in the uterus
So the NK cells focus on attacking viral infected cells and cancer cells.
Red bone marrow - origin of all formed elements (1. RBCs, 2. WBCs, and 3.
Platelets)
The T cell production starts in the bone marrow --> thymus --> bone marrow to be
a mature T cell
Which country did we all originate from? Africa is a pretty good response.
Answer: Euroasia
Euroasia - fusion of Europe and Asian continents
During the separation of both continents, some of the Asians stayed in Europe
(e.g. Mongolians) and some of the Asians moved to North America (e.g. Native
American Indians)
The T cells came from the bone marrow (Euroasia) and then traveled to another
continent/country and then returned back to Euroasia.
B cells --> bone marrow and lymph nodes
T cells --> thymus (fetus) & bone marrow and lymph nodes (adult)
NK cells --> bone marrow and lymph nodes
 3 types of lymphocytes:
1. T cellscell-mediated immunity (Reason: These cells fight pathogens directly.)
2. B cells antibody-mediated immunity or humoral-mediated immunity
(Reason: use antibodies to fight)
Analogy: My older professors use the word "peroneus".
What is the modern name for "peroneus"?
peroneus longus = fibularis longus
antibody-mediated immunity = humoral-mediated immunity
3 types of lymphocytes:
1. T cells  cell-mediated immunity (Reason: These cells fight pathogens
directly.)
2. B cells antibody-mediated immunity or humoral-mediated immunity
(Reason: use antibodies to fight)
3. NK cells  immunological surveillance (Reason: They are like police officers
patrolling the area for bad guys (viral infected cells or cancer cells))
Analogy: Even in the army, there is the army police.
Let's talk about the 3 types of tonsils (lymphoid tissue):
1. Pharyngeal tonsil - superior and inside the facial bones (usually cannot be seen)
2. Palatine tonsil - located near or on the soft palate
Usually the removal of tonsils is for the palatine tonsil.
3. Lingual tonsil - located at the base or root of tongue
All 3 types of tonsils help fight and remove pathogens from the food, drinks, and
air we breathe.
Any questions about tonsils?
Reminder: Lymph nodes are the production sites of lymphocytes and also the
communication to alert lymphocytes of possible pathogens.
On the surface, many people think that the lymph node looks like soybeans.
The cross section of a lymph node has 3 major regions:
1. Outer cortex - makes B cells
2. Deep cortex - makes T cells
3. Medulla, medullary sinus, or medullary cord - makes B cells
This is my pneumonic to remember which region produces why type of
lymphocyte.
Turkey sandwich
Bread --> B for bread and B for B cells
Turkey --> T for turkey and T for T cells
Bread --> B for bread and B for B cells
Does this pneumonic help?
There are dendritic cells in the lymph node.
Dendritic cell = Antigen-presenting cell (APC) - immune cell that presents Ags
randomly for other lymphocytes to see or evaluate
Do you remember the difference between antigen (
Ag) and antibody (Ab)?
What is the definition of:
1. Antigen (Ag)
and
2. Antibody (Ab)?
Antigen (Ag) - cell surface marker and it may trigger an immune response
Not all Ags trigger an immune response.
1.
Ag is from your liver cell or heart cell --> no immune response
Pathology: Autoimmune disease - immune response or attack to your own cells,
tissues, and organs
vs.
1. Ag from a pathogen (bacteria, virus, mold, protazoa, etc.) --> definitely an
immune response
Is it clear that not all Ags trigger an immune response
2 Major types of antigens:
1. Pathogen - contagious and causes disease
e.g. Bacteria or virus
2. Allergen - not contagious and will not cause disease, but you could feel sick or
die of complications (only if serious like in anaphylaxis)
These 2 will trigger an immune response.
Antibodies (Abs) - "Y shaped molecules" and are really plasma proteins or
immunoglobulins (Igs)
So the antibodies are the actual proteins that fight in the immune response.
Going back to dendritic cells or APCs,
1. Present Ags randomly
a. Present a WBC Ag --> Nothing happens
b. Present a viral Ag --> Lymph node becomes activated and possibly enlarge
Result: The lymph node becomes active in making T cells and B cells to fight that
particular antigen from the virus.
I think of the dendritic cell or antigen-presenting cell (APC) as the "display case" of
items that customers may want to buy in a store.
e.g. I see a pair shoes that look nice in color and style.
If I want to buy that particular pair of shoes, I need to find the shoe box with the
correct shoe size.
Do you understand the meaning or purpose of dendritic cells?
Let's talk about the thymus.
1. Active as a fetus and makes T cells
2. Inactive when a child is born
3. Located right above the heart (thorax)
4. Two lobes - right and left
5. Lobules - miniature lobes
6. Septa - tissue that separates the lobules
Alzheimer's disease - original cause was plaques in the brain
More recently they found out these plaques were caused by dental disease
(bacteria in the gums spread to the brain).
You should always check in on the new biology discoveries.
Let's talk about the spleen.
SP - looks like a small flattened stomach
Eastern medicine: SP/ST are organ pairs
1.
white pulp - filters out WBCs
2.
red pulp - filters out RBCs
filter = remove dying or dead cells
RBC life span = 120 days
After 120 days, the RBC usually is not working too well or too old. So the SP will
filter out dying or dead cells.
Innate defense is an important part of immunity.
What does the word "innate" mean here?
original from body
like nature killer cells?
not from a flu shot
or mother
innate - born with or at birth
Do you all agree we are born with skin?
Skin - very important barrier that blocks pathogens from entering the body
When a person experiences a burn or serious one like 3o burn, they die of
complications not from the burn itself but from excessive or extreme exposure to
pathogens in the air.
Even a wound is a weakness for possible infection.
Any natural opening the skin is vulnerable to pathogens.
e.g. Eyes, nose, mouth, ears, and genitals
Next week, we will continue with innate defenses.
We will start with phagocytes.
2021/10/25 CH22 Lymphatics
We started "innate defenses" last week and talked about the skin as being a
barrier to pathogens. This is our most important line of defense in "prevention"
by blocking pathogens before they enter the body.
What is the meaning of "innate"?
1. innate - born with or at birth
2. Phagocytes = Macrophages - general immunity where WBCs engulf foreign
pathogens (without knowing what type of pathogen)
phago = eating
cytes = cells
macro = large
phages = eaters
Analogy: Think of them as "Pac-man".
a. Fixed or free macrophages
b. WBCs - neutrophils, eosinophils, and monocytes
Any questions about these phagocytes?
3. Immunological surveillance or NK (natural killer) cells
Do you remember that 1 of the 3 lymphocytes is NK cells?
What are the other 2 lymphocytes?
You must use capital letters.
3 types of lymphocytes:
1. T lymphocytes (T cells)
--> cell-mediated immunity
2. B lymphocytes (B cells)
--> antibody-mediated (or humoral-mediated) immunity
3. NK (natural killer) cells
3. Immunological surveillance or NK (natural killer) cells
What are the other 2 lymphocytes?
You must use capital letters.
3 types of lymphocytes:
1. T lymphocytes (T cells)
--> cell-mediated immunity
2. B lymphocytes (B cells)
--> antibody-mediated (or humoral-mediated) immunity
3. NK (natural killer) cells
--> immunological surveillance
Does this sound familiar from last week?
We are only focusing on NK cells (not T cells or B cells) for the 3rd example of
innate defense.
Innate Defenses:
1. Skin - physical barrier
2. Phagocytes or macrophages - general immunity
3. Immunological surveillance - NK cells
Do you remember what type of cells the NK cells attack?
NK cells attack cancer cells?
What else do they attack?
NK cells attack:
1. Cancer cells --> abnormal cells
2. Viral-infected cells
Last week, we talked the relationship between how some viral-infected cells turn
into cancer cells.
e.g. HPV
What does HPV stand for?
Human papillomavirus
Elinor has the correct spelling.
NK cells:
1. NK cell orients its Golgi apparatus to face the abnormal cell
2. NK cell excoytosis perforin molecules
3. Perforin molecules line up in a circle to poke holes in the abnormal cell
4. Many of these holes will cause the abnormal cell to lyse open and die
perforate - puncture or make holes
We are all born with NK cells. So this is another type of innate immunity.
What is the purpose or function of the Golgi apparatus/complex?
- stores, packages, and transports products
e.g. Lipid (from SER) + Protein (from RER) --> Lipoprotein
This is an example of packaging.
These products can be transported within the Golgi apparatus and transport out
of the Golgi complex.
That is the transport process.
Sometimes the products remain stored in the Golgi apparatus for a shot period of
time.
Is that clear on the function of the Golgi complex?
Perforin is a packaged product. In fact, it is a destructive enzyme that can kill
abnormal cells.
Types of Innate Defenses:
1. Skin - physical barrier
2. Phagocytes = Macrophages - general immunity
3. Immunological surveillance - NK cells killing viral-infected cells or cancer cells
4. Interferons - chemical messengers that prevent or block a virus from infecting a
cell
Note: Both the skin and interferons prevent entry. (preventive measures)
Interferons are still being studied by scientists.
Here are possible theories:
1. Maybe the interferons prevent the virus from attaching or sticking to the cell
2. The interferons block the viral DNA or RNA from entering the cell.
3. Maybe the interferon blocks the viral DNA or RNA from entering the nucleus
4. The interferons could block the viral DNA or RNA from causing damage inside
the nucleus.
COVID-19 messed up the interferons so they do not work properly.
Reason: We do not know why or how COVID-19 messes up the interferons.
Interferons - interfere with VIRUSES
(not bacteria, not mold, not fungus, not protozoa, etc.)
Note: Virus - attacks the cell on the inside
Bacteria - attacks the cell mostly on the outside
Viruses are so much more complicated to deal with than bacteria
1.
Viruses - mutate quickly (vaccination is very complicated)
2.
Viruses - attack on the inside of the cell --> sometimes not detected by the
immune system
So viral infections are difficult to treat while most bacterial infections will either
be treated with antibiotics or it pass soon where there is recovery.
Even antibiotics can result in bacterial resistance. So bacteria can mutate, but not
as fast as viruses.
If you become an immunologist or medical doctor, you should learn the different
types of interferons.
For our course, we cover interferons based on function --> interfere with viruses.
What is the difference between virus and retrovirus?
e.g. Common cold - caused by rhinovirus (regular virus)
e.g. HIV or COVID-19 - caused by retrovirus
Both viruses and retroviruses use the cells to reproduce.
3 types of lymphocytes:
1. B cells
2. T cells
a. Helper T cells = CD 4 cells
b. Cytotoxic T cells = CD 8 cells
c. Memory T cells
d. Suppressor T cells
3. NK cells
Yue, so I asking about virus vs. retrovirus, not talking about different types of T
cells.
Virus does replication: viral DNA --> viral DNA
Retro - backwards or going backwards (opposite direction)
Retrovirus - reverses from RNA --> DNA (it does reverse transcription)
Let's review the 3 major processes in the cell:
1. Replication: DNA --> DNA
2. Transcription: DNA --> RNA
3. Reverse transcription: RNA --> DNA (e.g. retrovirus)
4. Translation: RNA --> Proteins
The virus proceeds forward either with replication or transcription.
vs.
vs.
Retrovirus - injects viral RNA into the cell nucleus and that nucleus does "reverse
transcription" to make viral DNA.
a. RNA --> DNA
b. DNA --> RNA
c. RNA --> Proteins
For some reason, drugs work better on viruses, than on retroviruses.
 interferons:
1. Alpha (a) interferon - released by infected cell to attract NK cell to kill viralinfected cell (prevent the reproduction and spread of viruses).
fibroblasts: cell makes new skin tissue to repair the injury.
Yue got confused with the blood clotting process.
Blood clotting - prevent blood loss
Fibrinogen (plasma protein) --> Fibrin + Trapped RBCs --> Real blood clot
And
Fibroblasts generate new skin tissue to replace the damaged or lost skin tissue at
the wound site.
This skin tissue is called "scar tissue".
2. Beta (b) interferon - secreted by fibroblasts to slow down inflammation (usually at
the wound site).
3. Gamma (g) - secreted by T and NK cells to stimulate macrophage activity.
 Summary of Innate Defenses:
1. Skin
2. Phagocytes
3. NK Cells
4. Interferons
5. Complement system - involves complement proteins or "C proteins".
a. C proteins floating in plasma.
b. Each C protein pokes a hole (similar to perforin from NK cells).
c. Foreign cell (e.g. bacteria) or an infected body cell cannot handle all these
holes.
d. The bacteria or infected cell lyses open and dies.
 Compare 2 scenarios:
1. NK Cells  Golgi vesicles  Perforin  Pores/holes  Cell lysis
2. C Proteins (from plasma of blood)  Pores/holes  Cell lysis
**Both have the same outcomes, but the source is different.
6. Inflammation - localized response (e.g. wound area).
a. Increased blood flow (redness)
b. Phagocytes activate (sometimes you see puss --> possible sign of infection).
c. C proteins are activated.
d. Blood clotting - prevent blood loss.
e. Regional elevation of temperature - localized to a small area.
7. Fever - whole body is dealing with elevated temperature.
Reason: Pyrogen proteins increase our body temperature above 98.6 oF (or 37
oC).
pyro = fire
 Complement System: Complement System - involves C proteins to lyse or kill
pathogen. Involves C proteins to cause lyses in pathogens or infected cells.
1. Classical pathway - requires antibodies (Abs), which tag the pathogen with
accuracy so the C proteins can destroy the pathogen with accuracy.
Requires Abs (prior exposure to pathogen) and is much more accurate (faster
recovery)
a. Abs tag the pathogen with accuracy.
b. C1 - C4 proteins show up.
c. C3b protein attaches to pathogen cell wall/membrane.
d. C5 - C9 proteins form MAC (membrane attack complex)
e. Too many holes will result in pathogen lysis where it dies.
This classical pathway only works if you have the antibodies for that pathogen.
Question: How long does it take for the body to make Abs?
Most textbook will say it takes the body about 2-3 weeks to make antibodies.
This classical pathway only works if you have prior exposure to this pathogen.
Otherwise, you do not have such antibodies to tag this pathogen.
Also, waiting 2-3 weeks to form these antibodies will be dangerous.
2. Alternate or Alternative pathway - no Abs present because this is first-time
exposure to pathogen.
 Better safe than sorry.
-No Abs present (1st time exposure) and C proteins will still kill the cell (might
be healthy one by accident) stronger symptoms or illness.
There is a lot of "friendly fire" here.
With the alternate pathway, the C proteins will kill this cell, even though it is
not sure it if it is a pathogen.
Pro: You are trying to be safe.
Con: You might end up killing a healthy cell
Result: The first time you get sick from something new, the symptoms are
usually bad.
 Immunity:
1. Adaptive immunity - immunity acquired not at birth, but due to exposure
from another source.
Let's talk about "adaptive immunity" - exposed to produce Abs or you acquire
those Abs for immunity
Key point: These Abs were not present at birth.
(1) Active (work hard) - exposure to antigen (Ag) and your body needs to
produce those Abs.
(2) Passive (lazy way) - You receive those Abs directly (no need to make them!).
2. Innate immunity - born with these antibodies.
When would you be born with these antibodies?
e.g. Type A blood - born with B antibodies.
e.g. Type B blood - born with A antibodies type
e.g. Type O blood - born with both A and B antibodies.
Notice that Rh factor is not listed (Rh Abs form only after exposure to Rh+ blood).
 The other category is:
1. Natural - from nature or happens accidentally as a result of nature.
2. Artificial - from a needle or injection (not natural).
 Forms of Immunity:
1. Innate immunity - born with Abs (no need to be exposed to Ags or make Abs/be
given Abs).
2. Naturally acquired active immunity - naturally exposed to Ags (e.g. bacteria or
virus).
e.g. Getting sick - Your body has to fight those Ags (e.g. bacteria or virus) by
producing Abs.
Your body works hard to make antibodies.
natural - natural exposure to Ags.
acquired - exposed to Ags.
active - body has to create Abs.
3. Artificially induced active immunity - needle or injection of Ags (e.g. partial Ag
from a virus or bacteria) and such exposure causes your body to create Abs.
e.g. Vaccineinjecting partial or weakened Ags to cause the body to create Abs.
ex: The COVID-19 vaccine is fragments of COVID-19 mRNA.
Analogy: This is like a fire drill to prepare for the fire.
artificial - needle or injection.
induced - using a needle (done with intention)
active - body has to work hard to create Abs.
4. Naturally acquired passive immunity.
e.g. Breast feeding - mother naturally gives (acquires passively) her Abs to the
newborn child.
natural - mammals naturally breastfeed their offspring.
passive - child receives those Abs, no need for the child to make those Abs.
5. Artificially induced passive immunity.
e.g. Antidote it can fight toxins/poisons.
These toxins or poisons are Ags.
 Venomous snake bite - venom (poison) can cause a person to die within a few
hours.
 Insect or bug bites - venom from spiders or certain bugs.
 Rabies - bitten by an animal with rabies.
These are emergency situations where such toxic venom (Ags) can kill within a
few hours. So, you cannot wait 2-3 weeks to produce those Abs to recover.
The doctor injects an antidote (Abs) to fight those toxic Ags.
artificial - needle or injection.
induced - inject on purpose (intentional)
passive - you are receiving those Abs through the injection.
 Adaptive defenses:
1. T cells  fight directly by attacking foreign cells or infected body cells.
2. B cells  fight indirectly by creating antibodies to fight pathogens
B cells --> Plasma cells --> Antibodies
plasma cells - activated B cells with lots of RER to make plasma proteins called
"immunoglobulins".
Immunoglobulins (Igs) = Antibodies (Abs).
 What is the difference between a white blood cell and an antibody?
WBC - living cells that fight.
Abs - proteins (Immunoglobulins) produced by B cells (type of WBC).
 In the immune system, there are 2 groups of cells:
1. Immune cells - WBCs, phagocytes, macrophages, antigen-presenting cells
(APCs), etc.
Analogy: Soldiers (with the weapons) to fight in war. If they see an enemy, the
immune cells know how to fight back.
2. Body or somatic cells - HT, LV, KI, BL, ST, skin, hair, etc.
Analogy: Civilians (without the weapons) and cannot fight back.
In most cases, they have to follow the people who conquer them.
e.g. A viral infected cell happens in body cells, not in immune cells.
Any infected body cell must be destroyed to prevent further infection.
(1) Save - WBCS and immune cells --> let them fight - They are tagged with
MHC II (Class II MHC).
(2) Kill - Pathogen, foreign cells, and infected "body" cells. -Infected body cells
are trickier to detect.
When a WBC or immune cell encounters a cell with MHCI (Class 1 MHC), it
know it is a somatic or body cell.
Then it must check out that somatic cell to see it is alright.
 WBC or immune cell must do the following:
1. Are you soldier (MHC II) or civilian (MHC I)?
2-1. If MHC II, leave it alone whether there is or is not a pathogen.
Or
2-2. If MHC I, check to see if it is healthy.
a. If MHC I cell is healthy, then leave it alone.
b. If MHC I cell is unhealthy (abnormal or infected), then kill it.
 Fig 22-18a
Cell with MHC I This must be a somatic or body cell.
Two different meanings:
(1) Cell with MHC I (somatic or body cell) that displays foreign Ag means that a
WBC (Cytotoxic T cell or CD 8 cell) must attack and destroy it to prevent spread of
infection.
(2) Cell with MHC II (WBC or immune cell) that displays foreign Ag means that the
other WBCs need to prepare and fight this foreign Ag (leave that WBC alone).
Next week, we will spend a lot of time on the details with what happens when:
1. Cytotoxic T or CD 8 cell encounters an MHC I cell.
2. Helper T or CD 4 cell encounters an MHC II cell.
Reminder: Helper T cells stimulate and coordinate the T and B cell activities.
a. Helper T cell will activate the cytotoxic T cell to fight pathogen or infected
cells.
b. Helper T cell will activate B cells to make plasma cells, which form antibodies.
That is why Cytotoxic T cell = Tc cell = CD 8 cell = CD 8+ cell is linked with Class 1
MHC = MCH I protein on cells.
Vs.
That is why Helper T cell = Th cell = CD 4 cell = CD 4+ cell is linked with Class II MHC =
MCH II protein on cells.
We will start on slide 27, but make sure you understand the MHC I <--> Cytotoxic
T cell = CD 8 cell connection and MHC II <--> Helper T cell = CD 4 cell connection.
11/01/2021
We are going to finish Ch. 22 - Lymphatics. Then we will review for Quiz 3 on Ch. 22 Lymphatics and Ch. 23 - Respiratory System. Today's lecture on immunology will be
more difficult than the previous lectures for Ch. 22.
 Let's do a quick review:
1. Somatic (body) cell will display MHC I (Class 1 MHC).
a. Normal Ag (from the cell)  Cytotoxic T cell (CD 8 cells) will leave this somatic cell
alone.
b. Abnormal Ag (from bacteria or virus)  Cytotoxic T cell (CD 8 cells) will attack and
eventually destroy the infected cell.
Reason: This somatic cell is going to spread the infection. This is like a civilian that is
shot or wounded and better off dying.
vs.
2. Immune cell (e.g. APC) or WBC (e.g. Lymphocyte) will display MHC II (Class II MHC).
a. Normal Ag (from the body)  Helper T cell (CD 4 cells) will not activate the T and B
cells to fight (no activation of immune system).
b. Abnormal Ag (from pathogen or allergen)  Helper T cell (CD 4 cells) will activate
both T cells and B cells to fight the foreign Ag (activate the immune response).
Reason: The immune and WBCs know how to fight back. So you would never kill or
destroy any cells with MHC II, whether there is normal or abnormal Ag.
 The steps of what happens with an infected somatic cell that displays MHC I with
an abnormal Ag.
1. Antigen recognition:
The cytotoxic T cell notices there is an abnormal Ag on the somatic cell.
2. Co-stimulation - mutual communication and feedback between somatic cell and CD 8
cell.
a. CD 8 cell - sends a signal to verify with infected somatic cell to ask if there is really an
infection.
b. Infected somatic cell responds back and confirms there is an infection.
3. Activation and Cell Division - produce active Tc and memory Tc cells
a. Active Tc cells will fight the foreign Ag.
b. Memory Tc cells will remember how to fight after winning the battle.
4. Destruction of Target cells  infected cell is destroyed as well as other infected cells.
a. Perforin - poke holes and destroy the pathogen cell membranelysis and cell death.
Do you remember NK cells release perforin?
(1) NK cells - orient Golgi apparatus and exocytose the vesicles with perforin.
(2) Complement system - C proteins found in the blood plasma that also poke
holes (like perforin).
b. Cytokine - stimulate apoptosis (programmed cell death).
c. Lymphotoxin - disrupts the cell metabolism.
e.g. If the infected cell is produce more viral particles, you completely that stop that
process.
 The steps of what happens with an immune cell or WBC that displays MHC II with
an abnormal Ag.
1. Antigen recognition: The helper T cell notices there is an abnormal Ag on the immune
or WBC.
2. Co-stimulation - mutual communication between immune cell and CD 4 cell to be
sure there is really a foreign Ag.
a. CD 4 cell - sends a signal to verify with immune cell to ask if there is really an
abnormal Ag (from pathogen).
b. Immune cell displaying the abnormal Ag on MHC II confirms back that the immune
system needs to be activated to fight foreign Ag
3. Activation and Cell Division - produce active Th and memory Th cells
Th = helper T cells
a. Active Th cells will activate more T and B cells to fight.
b. Memory Th cells will remember how to launch the immune response.
**There is no step 4 of cell destruction.
Reason: These immune cells or WBCs know how to fight back. So do not destroy these
cells here.
 We know that once the Tc and Th cells are activated, then start doing their job.
Tc cell  destroy infected cell or the pathogen itself
Th cell  activating the immune system (activate both T cells and B cells)
However, we do not know the details of how the B cells are activated to produce
antibodies.
 B cells  Plasma cells  Antibodies.
Anatomy of B lymphocytes (cells)
1. MHC II protein  "soldier".
2. Antibody on the surface called IgD
Ig = immunoglobulin
Ab = antibody
Ig = Ag - both are plasma proteins for fighting foreign pathogens
Do you remember that Ig is the same as Ab?
Both are the Y-shaped molecules.
 There are 5 types of classes of antibodies or immunoglobulins:
1. IgG = most common, able to cross placenta.
embryo - ball of cells
fetus - larger and species is known
(1) 1st trimester - embryo (ball of cells).
Embryo - between 1 day and 8 weeks
Less controversy to abort an embryo than a fetus.
(2) 2nd and 3rd trimesters - fetus (head, arms, legs, etc.)
2. IgE - found on basophils and mast cells, which both can release histamine.
(found on mast cells and basophils --> allergic response or inflammation due to
wounds.)
Histamine causes allergies.
(1) Hives - itchy red spots
(2) Runny nose
(3) Itchy red eyes
(4) Itchy throat
basophils  allergy related.
mast cells  inflammation at the wound site.
3. IgD - surface of B lymphocytes or B cells.
(found on the surface of B cells --> may lead to sensitization)
a. IgD - binds to normal Ag  nothing happens.
b. IgD - binds to abnormal Ag (from pathogen)  Sensitization.
4. IgM - five-antibody starburst for agglutination of Ags.
(5 starburst shape (5 IgMs that come together) to agglutinate foreign
substances)
e.g. If you are type A blood, you are born with B Abs, which are IgMs.
Foreign Ag of B blood will be agglutinated by B Abs, which are IgMs.
These blue Y-shaped molecules are actually B Abs, but they agglutinate "B
blood" because they have 5-starburst shape. So, the IgM is really 5 Abs coming
together to form the 5 corners of the starburst. This allows for the
agglutination of foreign blood or substance.
5. IgA - found in body fluids
e.g. Mucus, tears, saliva, semen, vaginal fluids, plasma, etc.
Reason: Secretory piece allows this IgA to dissolve into water.
e.g. Notice that the eyes are constantly exposed to the air. Why is it that we do
not have constant eye infection?
Reason: There are plenty of IgA dissolved in the tears to keep fighting foreign
Ags in the air.
**Pay attention to IgD because we are going to go back to the slide on B cell
sensitization.
 continue: Anatomy of the B cell
1. MHC II  lets us know this is a WBC.
2. IgD  lets us know this is a B lymphocyte or B cell.
 Let's talk about sensitization (the steps to activate B cells):
(1) Foreign Ag binds to IgD.
(2) Sensitized B cell.
In some ways the "antigen recognition" with cytotoxic T cells and helper T cells is
similar to B cell "sensitization".
(3) Co-stimulation - helper T cell (CD 4) and B cell confirms foreign Ag. Cytotoxic T
cells are activated by this.
(4) Activation - create more active B cells to create more antibodies.
a. Activate B cells (really plasma cells).
b. Activate memory B cells - need to remember how to make those Abs should
there be a repeat infection with this foreign Ag.
(5) Plasma cells (contain lots of RER and ribosomes) - make lots of plasma protein
(immunoglobulins)
That leads to the 5 possible types of Igs or Abs that may be produced.
So, plasma cell  Antibodies
 Antibody anatomy/structure:
1. Heavy chains - longer protein chains.
2. Light chains - short proteins.
3. Constant segment - same protein sequence from antibody to antibody.
Analogy: Even though humans look quite different, we all have the same 206 bones in
the body.
4. Variable segment - different from antibody to antibody.
 Variable segment - based on the Ag it recognizes.
e.g. Measles Ab, they all have the same variable segment to bind to the measles Ag.
Vaccination - typically the injection of partial Ag or weakened Ag
Hapten - partial Ag
Carrier molecules - present in the body
Hapten + Carrier molecule  Complete Ag shape.
e.g. COVID-19 vaccine is just a segment of mRNA from COVID-19 virus.
 topic:
1. IgG - most common, but shows up after IgM.
2. IgM - 5 starburst of 5 Abs shows up first.
Primary (1o) response - 1st time exposure  notice how there are not that many
Abs (takes time to produce them).
Focus: Making IgG (most common).
Secondary (2o) response - prior exposure to foreign Ag so the 2nd time exposure
will launch a massive production of Abs.
That is why 1st time exposure causes intense sickness and 2nd time exposure has mild
or few symptoms.
computer virus - created by humans
virus - come from nature and possibly man-made
e.g. Biological warfare  anthrax (believe it was made by humans)
Fig 22-25 shows the sequence of what type of WBCs show up when there is an infection.
Notice that most of the Abs made are in weeks 2-3.
Bacteria vs. Virus - both contagious pathogens
Bacteria - cell
vs.
Virus - not a cell (protein coat with DNA or RNA inside)
Virus - carries DNA inside
Retrovirus - carries RNA inside
Both COVID-19 and HIV are retroviruses.
Both do reverse transcription: RNA --> DNA
Then they both proceed with the normal metabolism:
1. Replication: DNA --> DNA
This is viral DNA.
2. Transcription: DNA --> RNA
3. Translation: RNA --> Proteins
 Going back to the bacteria:
Cell shapes include:
1. Cocci - spheres or circles
2. Rods - rectangular or oval
3. Spirochete - spiral shapes
vs
Going back to the viruses...
1. Protein coat
e.g., Spikes on the COVID-19 looks like the "radiating rays of a sun" call "corona"
2. DNA or RNA strands inside
3. No nucleus and no organelles --> not a cell!
The virus/retrovirus injects its genetic material into the cell and eventually becomes of
the cell's DNA. So, the cell's DNA usually makes cellular proteins.
Instead, the cell is using the viral DNA to make viral proteins and viral DNA/RNA.
So, the infected somatic cell ends up being a "virus factory".
That is why it is important for the cytotoxic T cells to destroy the infected cell before it
releases billions of viral particles.
You will see a word called "opsonization" at the bottom for bacteria.
opsonization - producing proteins to provide friction.
What the immune system does is because WBCs can slide off of bacteria, the
opsonization provides friction to attach and attack the bacteria.
Analogy:
1. You try to climb a slimy wall and you keep falling or sliding off.
vs.
2. You have rocks sticking out and holes in the wall. Now you can climb or attach to that
wall.
REView:
 the origin and the names of these lymphocytes:
1. T lymphocytes (T cells) - come from thymus (as a fetus) --> "cell-mediated
immunity"
2. B lymphocytes (B cells) - come from bone marrow --> "antibody-mediated
immunity or humoral-mediated immunity"
3. NK cells - comes from bone marrow --> "immunological surveillance" (looking for
viral infected cells or cancer cells).
 3 types of tonsils:
1. Pharyngeal
2. Palatine
3. Lingual
 Cross section of lymph node:
1. Outer cortex --> makes B cells
2. Deep cortex --> makes T cells
3. Medulla --> makes B cells
Medullary sinus or medullary cord - both regions refer to the medulla.
 Dendritic cell = Antigen-presenting cell (APC) - randomly displays Ags that enter the
lymph node
a. Normal Ag (from the body) - nothing happens
b. Abnormal Ag (from pathogen or allergen) - lymph node becomes active (sometimes
swollen or enlarged) because that means B and T cells are being produced or active to
launch an immune response.
 Thymus - thymosin hormone helps produce T cells in the fetus (stops at birth)
After birth, T cells come from bone marrow or lymph nodes.
 Spleen - filter blood
1. White pulp - filters WBCs
2. Red pulp - filters RBCs
 Make sure you know and understand the different types of innate defenses.
innate - born with or at birth.
1. Physical barrier --> skin
2. Phagocytes --> macrophages, neutrophils, and monocytes
3. Immunological surveillance --> NK cells
4. Interferons - chemicals that interfere with VIRUSES
5. Complement system - use C proteins to destroy pathogens
a. Classical pathway - requires Abs (prior exposure to Ag) for an accurate immune
response
b. Alternate pathway - does not require Abs (first time exposure) and not so accurate
in fighting pathogens or infected cells
--> Better safe than sorry (you might lose healthy cells)
6. Inflammation - localized response in the body
e.g. Wound
e.g. Hives
7. Fever - elevated body temperature to speed up immunity.
 Make sure you understand the 5 forms of immunity:
1. Naturally acquired active immunity - e.g. getting sick.
2. Artificially induced active immunity - e.g. getting a vaccine
3. Naturally acquired passive immunity - e.g. breast feeding
4. Artificially induced passive immunity - e.g. getting an antidote
5. Innate immunity - e.g. being born with the antibodies (no need to make them or get
them elsewhere).
 That leads to the lecture today:
1. MHC I <--> Tc (CD 8 cell)
2. MHC II <--> Th (CD 4 cell)
That was for T cells.
 We talked about B cells.
Sensitization - involves the IgD (Ab on B cell surface) that binds to foreign Ag.
Otherwise, you have co-stimulation and activation with both T cells and B cells.
Only difference is when an infected somatic cell displays foreign Ag, then the last step
involves lysis or destruction of that cell.
All the other immune cells and WBCs remain alive because the MHC II works with Th (CD
4 cells) to launch an immune response.
I will e-mail you Quiz 3 afternoon, which will be due on Sun, Nov 7, at 10 p.m.
Quiz 3 (20 questions) will cover Ch. 22 - Lymphatics and Ch. 23 - Respiration.
2021/11/08
Let's review the antigen recognition and activation of cytotoxic T cells (CD 8 cell or Tc
cells).
1. Antigen recognition - cytotoxic T cell recognizes there is a foreign Ag.
2. Co-stimulation - confirmation from infected somatic cell to the cytotoxic T cell there is
a foreign Ag (which means infection of the somatic cell).
So, it co-stimulation that will activate cytotoxic T cells to divide.
3. Activation - division of both active Tc and Memory Tc cells.
4. Destroy the infected somatic cell - perforin, cytokines, and lymphotoxins will kill the
infected cell to prevent the spread of infection.
2021/11/08 CH 18- Endocrine System
1. endo -within or inside (traveling through the organ to organs).
 refers to hormones (chemicals) that affect other cells, tissues, and organs in the
body.
2. exo- outside (released to the outside).
e.g. Sebaceous gland - releases sebum on the outer surface of skin.
e.g. Sudoriferous gland - releases sweat on the outer surface of skin.
The focus is on endocrine or hormones is because they have an indirect role with
immunity.

How cell communicate in the body:
1. Direct communication - through gap junctions between 2 connected cells.
2. Paracrine - through extracellular fluid (ECF) to nearby cells.
3. Endocrine - through the bloodstream for cells, tissues, and organs far away.
e.g. Hormone = H (known chemical structure)
e.g. Factor = F (unknown chemical structure)
4. Synaptic - through the synapse or synaptic clef (narrow region between 2 cells)
e.g. Nervous system between the neurons and cells via neurotransmitters
(ACh = acetylcholine).
**Observation:
1. Endocrine - tends to be slower and long term.
e.g. Puberty - sex hormones take time to affect the sex characteristics of the body.
2. Nervous system - tends to be fast and short term.
e.g. Adrenaline rush - nervous system send a fast signal (feeling of panic attack).
 Do you feel comfortable with the hormones of the body from A&P 2?
1. Full name
2. Abbreviation
3. Where is it released?
4. What is the target and its effects?
 Review the brain structures that related to endocrine system:
1. Hypothalamus - biological thermostat that regulated homeostasis
e.g. Body temperature
e.g. Calcium balance
e.g. Metabolism is in balance
e.g. Fluid balance
Hypothalamus works as an on/off switch.
There are many on/off switches for the hormones.
e.g. GH-RH = growth hormone releasing hormone --> turns on growth hormone
(GH)
e.g. GH-IH = growth hormone inhibiting hormone - turn off growth hormone (GH)
On switch is RH or releasing hormone.
Off switch is IH or inhibiting hormone.
Hypothalamus --> Grandmaster gland
Pituitary --> Master gland
2. The pituitary gland has 2 lobes:
(1) Anterior pituitary - releases many different hormones such as:
a. ACTH
b. TSH
c. GH
d. PRL
e. FSH
f. LH
g. MSH
(2) Posterior pituitary - releases 2 hormones:
a. ADH
b. OXT
Trick: Memorize the 2 hormones in posterior pituitary as ADH and OXT. By default,
the others are probably in anterior pituitary.
**2 or 3 letter abbreviation - must use all capital letters
full hormone name - all lower-case letters or only capitalize first letter
e.g. OXT (all 3 letters are upper case)
e.g. oxytocin or Oxytocin
3. LH = luteinizing hormone
I also give full credit for "luteinizing hormone".
(missing an "i")
4. T3 = triiodothyronine
I also give full credit for "triodothyronine".
(missing an "i")
For 2 or 3 letter abbreviations, those letters have to be correct.
5. ACTH = adrenocorticotropic hormone
adrenoadrenal gland
What does the adrenal gland deal with here?
The adrenal gland produces hormones to deal with stress.
The causes of stress are so vast and diverse and that is why there are so many different
hormones that deal with stress.
Adrenal cortex  endocrine
Adrenal medulla  nervous system
ACTH = adrenocorticotropic hormone
adreno adrenal gland
cortico- = cortex (outer region)
tropic- = stimulated by hypothalamus
Eventually, ACTH is released by the anterior pituitary.
 Let's talk about the adrenal gland as whole.
1. Adrenal medulla releases:
a. E = epinephrine
b. NE = norepinephrine
Both E and NE are called "adrenalin".
This is the sympathetic nervous system responding to "fight or flight" response.
That is immediate danger or stress.
2. Adrenal cortex has 3 regions (deep to superficial).
(a) Zona reticularis - deepest region of the cortex releases "gonadocorticoids"
What is a gonad and how are different in the genders?
Male - testes to produce sperm.
Female - ovaries to ovulate egg.
Therefore, gonadocorticoids affect sex hormones
e.g. Males - testosterone and androgens.
e.g. Females - estrogen and progesterone.
** What are possible examples of reproductive stress?
1. Dating.
2. Mating (交配)
3. Reproductive issues - unable to conceive or labor.
(b) Zona fasciculata - middle region of the cortex  releases "glucocorticoids".
e.g. Cortisol - deals with mental stress
(c) Zona glomerulosa - superficial region of the cortex releases “mineralocorticoids.”
e.g. Aldosterone - retains Na+ ions (comes from salt) which helps keeps H2O in the
body (water conservation to prevent dehydration).
Scenario: You are stranded in the desert with your loved one and need for cram exam.
You may actually use all 3 regions of adrenal cortex.
e.g. gonadocorticoids - maybe you 2 are fighting.
e.g. mineralocorticoids - body needs to conserve H2O.
6. Anterior pituitary release TSH = thyroid-stimulating hormone.
TSH - affect thyroid gland which is responsible for metabolism
Thyroid gland will produce thyroid hormone that is made up of:
1. T3 = triiodothyronine
2. T4 = tetraiodothyronine or thyroxine.
3 = 3 iodines
4= 4 iodines
That is why you need iodine in your diet for metabolic reasons.
7. GH = growth hormone.
Anterior pituitary releases GH  Liver releases "somatomedins"  Bone, muscle, and
tissue growth
There have been questions about somatomedins, which are associated with GH and the
liver that affect bone, muscle, tissue growth.
soma = body
I think of "medins" like "mediate" or help the soma or "body" to grow bigger.
8. PRL = prolactin:
pro = to make or for
lactin = milk
PRL is active in women who just gave birth.
PRL is important for breast feeding to provide antibodies and milk to the newborn child.
9. Two sex hormones released by the anterior pituitary affect reproduction.
a. FSH = follicle-stimulating hormone.
 Male - follicle is the testes that produce sperm (Spermatogenesis).
 Female - follicle is the ovary that will ovulate an egg once a month.
**Note: Estrogen is also produced to allow for ovulation to take place.
b. LH = luteinizing hormone
 Male - testes will produce testosterone to affect the secondary (2o) sex
characteristics (bigger and stronger body, mustache/beard, body hair, lower
voice, sex drive, etc).
 Female - cause the uterus to make the uterine lining to allow for pregnancy.
10. MSH = melanocyte-stimulating hormone
 stimulates melanocytes (skin pigment cells) to produce melanin (dark pigment).
e.g. Albino - little or no production of melanin.
e.g. Africans and Indians - usually have more melanin expression.
**Caution: Do not mix up MSH which affects skin color with melatonin!
Melatonin - affects Circadian rhythms or the night-day cycle.
e.g. Sleep cycle
e.g. Menstrual cycle
The pineal gland (in the brain) produces melatonin.
Are you clear about MSH vs. melatonin?
e.g. What does MSH stand for?
Student 1: melanocyte-stimulating hormone --> full credit.
Student 2: melatonin-stimulating hormone --> zero credit.

Two hormones released from the posterior pituitary:
1. ADH = antidiuretic hormone or VP = vasopressin.
What is “diuretic”? 利尿劑 increased urine.
Examples of diuretics:
1. Coffee - intense need to urinate
2. Watermelon
 antidiuretic - against urination by reducing urine output (another to conserve H2O).
e.g. Dark yellow or amber in color - mostly wastes and not much water.
e.g. Pale yellow or colorless urine - lots of urination with mostly H2O leaving the
body.
So, ADH will cause the urine to be dark yellow or amber.
* Two H2O Conservation Hormones:
1. Aldosterone - retains Na+ to keep H2O in the body.
2. ADH or VP - retains H2O by reducing urine out.
 We have 2 hormones released from posterior pituitary:
1. ADH or VP.
2. OXT - smooth muscle contraction (biology) or bonding hormone (psychology).
 Females:
- Uterine contractions  PMS or Labor.
- Breast feeding  OXT to push the milk (stimulated by PRL) out of the breast
(glands and smooth muscle).
 Male:
- affects the ductus deferens/vas deferens for ejaculation.
so hormones affect behavior, emotions, stress, and also immunity.
e.g. Thymus - releases thymosin hormone to produce T lymphocytes or T cells as a fetus.

Feedback control of endocrine secretion:
Hypothalamus - on (RH or RF) / off (IH or IF) switch
R = releaseing
I = inhibiting
H = hormone
F = factor
Fig 18-8a.
 Hypothalamus: TRH (thyroid releasing hormone)
 Anterior Pituitary releases hormone 1: TSH (thyroid stimulating hormone).
 Endocrine organ (thyroid gland).
 Hormone 2: Thyroid hormones of T3 and T4.
 Target cells: all cells of the body are affected in metabolism.
 Hypothalamus RH is CRH (corticotropic releasing hormone).
 Anterior pituitary releases Hormone 1, which is ACTCH (adrenocorticotropic
hormone)
 Endocrine organ is adrenal cortex.
 Hormone 2 has 3 possible options: (1. Glucocorticoids, 2. Mineralocorticoids,
and/or 3. Gonadocorticoids)
 Target cells (depend on which 1 or 2 or 3 of the hormone 2 that is released).
 Hypothalamus RH is GnRH (gonadotropin releasing hormone).
 Anterior pituitary releases Hormone 1 is both FSH and LH.
Endocrine organ depends on gender.
Hormone 2 is based on gender
Target cells are based on gender.
Feedback mechanism is between the on/off switch effect in the hypothalamus.
e.g. PIH (prolactin inhibiting hormone) - turns off PRL production  no breast milk.
e.g. PRF (prolactin releasing factor) - turns on PRL production  produce breast milk.

Calcium regulation:
Reasons for calcium:
1. Skeletal muscle contraction.
2. Bone density.
3. Blood clotting.
4. Nerve communication to other cells.

We have 3 hormones that affect calcium levels in the body.
1. Calcitonin (CT) - released by thyroid gland and LOWERS calcium concentration in
blood.
2. Parathyroid hormone (PTH) - released by parathyroid gland and RAISES calcium
concentration in blood.
Note: Parathyroid is really the lateral regions of the thyroid gland.
3. Calcitriol (CTR) - released by kidneys and RAISES calcium concentration in blood
Notice there are 2 hormones that RAISE c .
calcium levels in blood because we tend to have a shortage of calcium.

The pancreas releases hormones that regulate "glucose".
1. Insulin - stores glucose as glycogen
e.g. Eat too much after a buffet
There is too much glucose.
Glucose --insulin--> Glycogen.
Pathology: Diabetes - issue with insulin
How do check for diabetes?
1. Urine test first (easier or more convenient)
2. Blood test next (if results from urine test are unclear)
What are you looking for in the urine that could be a sign of diabetes?
If insulin is deficient or not working, then the extra glucose ends in the urine.
2. Glucagon Glycogen --glucagon--> Glucose
This happens either after:
1. Fasting - intentional
2. Starving - not intentional
So, the body is using the reserves of glycogen to break it down to glucose.
**What is the difference between?
1. glucose - monosaccharide or 1 sugar unit preferred by the brain.
2. glycogen - polysaccharide or many sugar units as "animal starch" stored in both the
liver and skeletal muscles.
3. glucagon - pancreatic hormone that affects glucose metabolism.

Leptin:
 released by adipose tissue (fat) and suppresses appetite.
- Big appetite - very hungry and can eat a lot of food.
- No appetite - either full or do not want to eat.
Truth is that leptin is not always working that well.
You still obesity everywhere, even more so during this pandemic.
That is why you get all these ads about losing weight!
11/15/2021 CH The Endocrine System
Potential schedule:
(subject to change, if necessary)
11/15 - Finish Ch. 18-Hormones & Start Ch. 26 -Urinary System
11/22 - Finish Ch. 26 - Urinary System & Review for Quiz 4, which will be due on Sun
11/28 at 10 p.m.
11/29 - Go over Quiz 4 and Review for Big Exam
12/6 - Go over the Big Exam
Aldosterone is a type of "mineralocorticoid" and retains Na+, which helps keep H2O in
the body (prevent H2O loss).
In the heart, there are 2 types of hormones that regulate blood pressure.
1. ANP = atrial natriuretic peptide  found in the atria.
What are the atria of the heart?
atria - top 2 chambers (spaces) of the heart.
2. BNP = brain natriuretic peptide  found in the ventricles.
*Both ANP and BNP are heart hormones, which are released when there is too much
blood (high blood pressure).
**Review of whole blood:
1. Plasma - mostly H2O.
2. Formed elements - mostly RBCs.
If the blood pressure (bp) is too high, the HT walls may overstretch  cardiac
hypertrophy (enlarging the heart).
If the atrial walls stretch too much (too much blood), then ANP comes out.
If the ventricular walls stretch too much (too much blood), then BNP comes out.
**Both ANP and BNP regulate:
1. ADH - turn it off (no need to conserve H2O).
2. Aldosterone - stop retaining Na+ and H2O.
3. EPO (erythropoietin) which makes RBCs - turn it off too!
Net result: Reduce blood volume to reduce blood pressure.

Thyroid follicles：
1. Pump in iodide (I-)
2. Iodide (I-) + thyroglobulinT3 & T4
3. Exit into follicle cavity
4. Enter back into the cell
5. Lysosome - digests this thyroglobulin to release T3 & T4
** Thyroid hormone is made up of T3 & T4.
Thyroid hormone is made up of:
1. T3 = triiodothyronine.
2. T4 = tetraiodothyronine or thyroxine.

Calcium regulation hormones:
1. Calcitonin (CT) - from thyroid and bring down [Ca 2+] in the blood "tone it down".
2. Calcitriol (CTR) - from kidneys and brings up [Ca 2+] in the blood.
3. Parathyroid hormone (PTH) - from parathyroid and brings up [Ca 2+] in the blood.
**Make sure you read Table 18-3 on how thyroid hormone affects the body (increase in
metabolism).

What is the difference between Type 1 and 2 diabetes?
1. Type 1 - born with diabetes (believed to be an autoimmune system where your
immune system attacks the pancreas and insulin cannot be produced).
2. Type 2 - environmental where too much sugar (mostly high fructose syrup) damages
the pancreas and insulin production is reduced or stopped altogether.
 What hormone does the pineal gland release here?
 Melatonin
What does melatonin control?
 regulates circadian rhythms (night/day cycle).


A&P 2 review:
Pancreas
1. Exocrine cells - produce pancreatic juice or digestive enzymes.
a. Pancreatic amylase - digest amylose (starches).
b. Pancreatic lipase - digest lipids (fats and oils).
c. Pancreatic protease - digest proteins.
d. Pancreatic nuclease - digest nucleic acids (DNA or RNA).
2. Endocrine cells
a. Insulin - stores glucose as glycogen.
b. Glycogen - break down glycogen to make glucose available.
***Analogy:
1. glucose - food on the dinner plate.
2. glycogen - food in the pantry, fridge, or freezer.
3. fat/adipose tissue - food in the cellar or storage site (not readily accessible).

What does leptin do when release from fat?
When you have time, read about angiotensinogen, angiotensin I & II on how it works
with EPO, ADH, and aldosterone in regulating blood pressure.
RAS - reticular activating system (neurology)

General Adaptation Syndrome (GAS). There are 3 phases:
1. Alarm phase - immediate or short-term.
e.g. Panic attack.
Notice that adrenalin rush may happen for the "fight or flight" response.
a. E = epinephrine.
b. NE = norepinephrine.
2. Resistance Phase - long term stress effects for days, weeks, or possibly years
Note: Many different hormones may be involved, depending on the type of long-term
stress.
a. Glucagon - make more glucose available.
b. ACTH - activate glucocorticoids, mineralocorticoids, and/or gonadocorticoids.
c. Renin-angiotensin system - regulate H2O levels and RBCs level to keep blood
pressure in balance (not too high or low).
3. Exhaustion phase - collapse of vital systems.
Note: Very dangerous and may lead to coma and death.
Our immune system is very much affected by stress.
The emotional, psychological, spiritual, and social aspects of life can have a great impact
on the immune system.
Ch. 26 - Urinary System

The urinary system does the following:
1. Remove waste products - important for a healthy immune system.
2. Regulate water volume that may affect blood pressure.

The different organs and structures:
1. Kidneys (KI or KD) - produce urine.
Notice the right kidney is lower than the left kidney.
The liver pushes the right kidney downward.
Both kidneys are retroperitoneal. What does that mean here?
 Both kidneys are fused to the dorsal side of the abdomen/peritoneal location.
2. Ureters - tubes that transport urine from kidneys to the bladder.
3. Bladder (BL) - stores urine.
4. Urethra - tube for urination from BL to the outside
a. Female - about 1 inch long  higher chance for urinary tract infection (closer to the
outside where pathogens may enter).
b. Men - about 4 inches long (not an erect penis).
i. Prostatic urethra - travels through prostrate.
ii. Membranous urethra - travels through urogenital diaphragm.
urogenital diaphragm - on/off switch between urination and ejaculation
Penis - either urinate or ejaculate.
iii. Spongy urethra - travels though penis.

Many organs have ligaments that keep them suspended or held in place.
If the organ drops or is in the wrong location, we usually call it "prolapse".

Trigone - triangle pattern inside the bladder
1 corner - opening for left ureter into bladder.
1 corner - opening for right ureter into bladder.
1 corner - opening from bladder into urethra.

There are 2 sphincter muscles.
What is sphincter muscle?
How is that different from orbicularis muscle?
Both sphincters and orbicularis muscles are circular muscles.
Action: Open or close.
1. Superficial orbicularis.
e.g. Orbicularis oculi - around the eyes.
e.g. Orbicularis oris - around the mouth
2. Deep sphincter or valve.
e.g. Esophageal sphincter.
e.g. Pyloric sphincter.
e.g. Ileocecal valve.

Going back to the urinary system, there are 2 sphincter muscles:
1. Internal urethral sphincter - involuntary muscle that naturally opens up when the
bladder is full with urine.
2. External urethral sphincter - voluntary muscle where we stop the urine from leaking
out.
 Urinary incontinence - cannot control the urine output
e.g. Ever laugh and accidentally urinate?
Urination = Voiding (empty the Bladder) = Micturition = Peeing
 Micturition reflex - natural mechanism for the body to urinate.
a. Local pathway - BL is aware that it is full and must urinate now or soon.
b. Central pathway - BL needs to let the brain know there is a full bladder and the brain
sends a signal that it is OK or not OK to urinate now or soon.
Once the central pathway is fully developed, the child no longer has to wear diapers.
 Slide 13 - Fig 26-4a Kidney Structure
1. Renal cortex - outer region of kidney.
2. Renal medulla - inner region of kidney.
3. Renal pyramid - triangular shape.
4. Renal lobe - triangle + cortex --> bigger triangle.
5. Renal columns - tissue between the renal pyramids.
6. Fibrous capsule - tough outer covering that keeps the kidney shape.
 Sequence for Urinary System:
Kidneys  Ureters  Bladder Urethra
 Let's focus on the details for...Kidneys  Ureters
Kidneys (nephrons)  Renal papilla Minor calyx  Major calyx  Renal pelvis 
Ureter.
 Fig 26-5 is a zoom in on the kidney lobe (renal pyramid + cortex) for blood
circulation.
Renal artery  Segmental arteries  Interlobar arteries (between the lobes) 
Arcuate arteries (arcs around the lobe) Interlobular arteries Afferent
arterioles (small arteries towards glomerulus)  Glomerulus (ball of capillaries)
 Efferent arteriole (leaving the glomerulus)  nephron - smallest unit of kidney
sarcomere - smallest unit of muscle
osteon - smallest unit of bone
cell - smallest unit in biology
atom - smallest unit in chemistry
red --> blood vessels (arteries)
purple --> tubules (nephron)
Peritubular capillaries (wrap around the nephron tubules) --> Venules (small veins) -->
Interlobular veins --> Arcuate veins --> Interlobar veins (between the lobes) --> Renal
vein
red - blood vessels, e.g. peritubular capillaries
purple - tubules, e.g. nephron itself
absorption: purple --> red
Reason: The nutrients in the purple is part the kidneys to become urine. You want to
reabsorb it back to the blood stream to be used by the body.
secretion: red --> purple
Reason: The waste products in the red is part of the bloodstream. You want to secrete
it into the tubules to become urine in the kidneys to be excreted by the body.
11/22/2021 CH 26 CONT’

Kidney is important for 2 major functions:
1. Remove waste products.
2. Regulates water volume.
** Kidney - made up of billions or trillions of nephrons.
** nephron - smallest unit of kidney.
** Cell - smallest unit in biology

Nephron consists of:
1. Glomerular Capsule or Bowman's Capsule or Renal corpuscle.
2. Proximal Convoluted Tubule (PCT) - absorb nutrients.
3. Nephron Loops or Loop of Henle - make more concentrated urine.
4. Distal Convoluted Tubule (DCT) - secrete wastes.
5. Collecting duct - variable water reabsorption.
6. Papillary duct - urine that will leave the kidneys and go into the ureters to reach the
bladder.

There are really 2 compartments:
1. Kidney or tubules (purple) Trash can (filtrate and urine)
2. Blood vessels (red)  Home (keep valuables such as nutrients)

Terminologies:
1. absorption - we want it.
e.g. glucose
e.g. amino acids
e.g. fatty acids
Absorption: purple (nephron with filtrate)  red (blood vessels).
reabsorption and absorption - about the same meaning.
The opposite of reabsorption is "secretion".
2. secretion - we want to get rid of it
e.g. ammonia
e.g. acids
e.g. creatinine
e.g. urea or uric acid
Secretion: red (blood vessels) --> purple (nephron with filtrate or urine).

Quick review of blood flow:
Afferent arterioles --> Glomerulus (ball of capillaries) --> Efferent arteriole -->
Peritubular capillaries.
**Note: Glomerulus has more pores and holes where all the contents of the blood
(except RBCs and WBCs) get dumped into the Bowman's capsule.
In the beginning, the nephron has filtrate with both nutrients and wastes.
At the end, the nephron has urine with mostly wastes.
Nephron consists of...
1. Glomerular Capsule or Bowman's Capsule or Renal corpuscle - filtrate (both nutrients
and wastes).
2. Proximal Convoluted Tubule (PCT) - absorb nutrients.
3. Nephron Loop or Loop of Henle - make more concentrated urine.
Both PCT and Nephron loop involve reabsorption (purple red).
4. Distal Convoluted Tubule (DCT) - secrete wastes
(red  purple)
5. Collecting duct - variable water reabsorption
a. Dehydrated - continue to reabsorb more H2O (purple  red).
b. Over hydrated - not reabsorb any more H2O (nothing happens).
6. Papillary duct (kidney)  Ureters  Bladder  Urethra.
You can see how the kidney is really a "filter of the blood" (besides the spleen).

Nephron loop - focuses on obligatory H2O reabsorption based on working with
NaCl concentration levels
"Water follows salt"
Nephron loop - OBLIGATORY H2O reabsorption (mandatory)
vs.
Collecting duct - VARIABLE H2O reabsorption (depends on the needs of the body).

There are 2 types of nephrons:
1. Cortical nephron - shorter and mostly in the kidney cortex.
 Peritubular capillaries (blood vessel)
2. Juxtamedullary nephron - longer and mostly in the kidney medulla
 Vasa recta
**Reason: Longer nephron loop (Loop of Henle) makes the juxtamedullary nephron
much longer.
Q: What does the nephron loop do here?
 Nephron loop - reabsorbs H2O
Since the juxtamedullary nephron has a longer nephron loop, which gives it more time
to absorb even more water.
purple  red
Blood vessels get lots of H2O back.
Filtrate becomes more concentrated (loss of H2O).
Final answer: Juxtamedullary nephron is able to make more concentrated urine.
Pale- or light-yellow urine (loss of lots of H2O)  mostly cortical nephrons.
Dark yellow or amber urine (retain lots of H2O in the blood)  mostly juxtamedullary
nephrons.
Urine - never has blood in it.
Women - possible reason is contamination from menstrual fluids.
Men - never see blood in urine.

Table 26-2 Normal Lab values for Solutes in Plasma and Urine:
Na+-K+ pump is an antiport (travel in opposite directions)
We have too much Na+ in our diet (comes from salt) so we always end up losing lots of
K+ in the urine.
Notice that in Table 26-2, the kidney is very efficient in getting all the nutrients back into
the blood (plasma) and dumping all the wastes into the urine (filtrate).

Summary to understand about hormones:
Angiotensin I/II (similar to ANP and BNP) regulate both ADH and Aldosterone to control
H2O levels in the body.
1. Thirsty  drink H2O (increase H2O volume).
2. ADH production  retain H2O by urinating less H2O out.
e.g. ADH shows up to the collecting duct to allow it to absorb H2O (maybe the person is
dehydrated).
3. Aldosterone release  retain Na+ which helps retain H2O in the body.
如果一個人喝了太多水，ADH 不會出現，但如果一個人脫水了，ADH 出現

Let's talk about how the Loop of Henle can affect the concentration of urine by
absorbing H2O (obligatory).
Countercurrent Multiplication Effect:
1. Countercurrent：
a. Descending limb of nephron loop - current is downward.
b. Ascending limb of nephron loop - current is upward.
2. Multiplication - present of NaCl in the blood multiplies the effect or reabsorbing even
more H2O back into the blood.
Note: Once the filtrate reaches the DCT (Distal Convoluted Tubule), all the wastes
(including excess NaCl in the blood) will go back to the nephron filtrate.
Note: The H2O remains reabsorbed back into the blood.
"Countercurrent multiplication" effect where the Nephron loop does its best to
reabsorb as much H2O as possible.

Table 26-5 General characteristics of Normal Urine
meat eater --> urine is more acidic
veggie --> urine is less acidic
Specific gravity (density compared to H2O)
d H2O = 1 g/ml or 1 g/cm^3
Notice that the specific gravity or density of urine is slightly higher than H2O.
Reason: Salts are slightly denser than H2O.
Let's say you are colorblind.
You cannot rely on the color of urine to determine if it is diluted or concentrated.
Instead, look at specific gravity.
1. If the urine density or specific gravity is closer to 1 or 1 g/ml, then it is dilute like H2O
vs.
2. If the urine density or specific gravity is somewhat greater than 1 or 1 g/ml, then it is
concentrated with salts (mostly wastes).
Water content:
Dilute urine  closer to 97% H2O
Concentrated urine  closer to 93% H2O.
Urine does not contain bacteria.
The urine still has tiny amounts of nutrients that attract bacteria to grow in the urine.
Collecting duct - additional absorption of H2O (might start as early as DCT if there is
severe dehydration)
***********
Afferent arteriole (small artery going towards the glomerulus)  Glomerulus (ball of
capillaries with filtration slits)  Efferent arteriole (small artery that leaves the
glomerulus)  Peritubular capillaries (cortical nephron) or Vasa recta (juxtamedullary
nephron)
************
Male: Kidneys --> Ureters --> Bladder --> Urethra (both urination and ejaculation)
Male urethra:
1. Prostatic urethra - passes though the prostate.
2. Membranous urethra - passes through urogenital diaphragm.
3. Spongy urethra - passes through penis.
************
I am going to show you Quiz 4 study guide to review the hormones from Ch. 18 Endocrine System.
How to study Ch. 18 - Endocrine System.
1. Full name of hormone
2. Abbreviation of hormone
3. Source of where the hormone or factor is released
Often the answer is "hypothalamus".
4. Sequence of how the hormone affects the cells, tissues, and organs in the body
(beginning to end).
5. Overall result of that hormone effect.
**Posterior pituitary gland releases only 2 hormones:
1. ADH
2. OXT
If not those 2 hormones, then most likely the other hormones must be released by
anterior pituitary lobe.
e.g. EPO comes from the kidneys, not so much stimulation from the brain.
What does EPO stand for? Erythropoietin
Any time you regulate blood volume, it is not directly affected by the brain.
Reason: ANP and BNP from the heart that regulate it.I
Angiotensin I/II from the kidneys that regulate it.
Group the hormones that regulate the same substance.
e.g. PTH, CTR, and CT all regulate calcium levels in the blood.
2021/11/29 Review Quiz 4 and Final exam
Everyone seems to be alright with Quiz 4 on Ch. 18 - Endocrine System (hormones) and Ch. 26 - Urinary System.
We will review Quiz 3 material (Ch. 22 - Lymphatics and Ch. 23 - Respiratory System) to prepare you for the Final Exam.
I will e-mail you the Final today and it will be due on Sun, Dec 5 at 10 p.m.
Victoria Ying
12:18 PM
We will go over the Final on Mon, Dec 6 at 12 p.m. noon.
If there is no major discussion about the final exam and you are alright or understand your course grades, then I will cover
Ch. 29 b - Genetics.
Final is more like a 2nd midterm on Ch. 22 - Lymphatics and Ch. 23 - Respiration (Quiz 3
material) and Ch. 18 - Endocrine and Ch. 26 - Urinary System (Quiz 4 material).

Review Ch 22
3 types of lymphocytes:
1. T lymphocyte (T cell)
2. B lymphocyte (B cell)
3. NK cell (natural killer cell)
 WBCs = white blood cells = leukocytes
Never let monkeys eat bananas
 1. Which of the following is responsible for stimulating the activation of both T
and B cells? Helper T cells = CD4
2. Which of the lymphocytes makes antibodies? B cells
Sometimes students will answer "plasma cells" and that is also fine.
B cells --> Plasma cells --> Antibodies
3. What is another name for antibody (Ab)
Both Andre and Yue are correct!
antibody = Ab = immunoglobulin = Ig
4. Which organelle is most important in the plasma cell for making antibodies?
NK cells use the Golgi apparatus to secrete perforin to "poke holes" and destroy infected cells or pathogens.
We are focusing on plasma cells, which are really activated B cells.
Ch. 3 - Intro to Cells
Golgi apparatus/complex - storage, packaging, and transport of materials
packaging --> make a more complex molecule
e.g. Carbohydrate + Lipid --> Glycolipid
e.g. Lipid + Protein --> Lipoprotein
Going back to antibodies, which you all agree can be immunoglobulins, what is the major component made here?
Immunoglobulins (Igs) are really plasma "proteins".
So the plasma cell is mostly RER and ribosomes in order to make the globulin plasma protein.
5. What are the 3 types of plasma proteins
Not fiber but the word is quite close.
and one more... globulins
 3 types of plasma proteins
1. albumin - makes plasma thicker
2. globulins
a. Immunoglobulins (Igs)
b. Transport globulins
3. fibrinogen - helps with blood clotting
If plasma cells have to make Abs or Igs, it must make a lot of proteins because these are really a type of plasma
"proteins".
So there are lots of RER and ribosomes in the plasma cell to make proteins.
Yue, the answer is lots of RER and ribosomes that make the proteins inside the plasma cell.
What does RER stand for?
RER = rough endoplasmic reticulum (fixed ribosomes)
vs.
ribosomes - usually they are freely floating around in the cytoplasm
Ribosomes - make proteins
6. Which lymphocyte is responsible for "immunological surveillance"?
NK cells (cells must be included)

When you start to recover from a cold, illness, or disease, which type of T lymphocyte plays an important role here?
2 possible answers here.
One of them is memory T cell - important to remember how to fight this pathogen or antigen.
What is the other one? Suppressor
T cells
Once you start to recover, you are winning the battle.
So there is no need to keep the immune system so active.
Ever notice that during a cold, flu, or illness, you feel weak, tired, and sometimes delirious.
8. Where are T lymphocytes made as a fetus and as an adult?
fetus: thymus ; So as an adult, the T cells are made in both bone marrow and lymph nodes.
9. Which part of the lymph node is responsible for making B cells? Outer cortex and Medulla (medullary sinus or medullary
cord).
10. We see dendritic cells in the lymph node. What is another name for dendritic cells?
APC = antigen-presenting cell = dendritic cell --> display Ags so the WBCs can figure out if there is an infection
a. Normal Ag from the body --> nothing happens
b. Foreign or abnormal Ag --> lymph node becomes active and makes both T and B cells
11. Which part of the spleen is responsible for filtering WBCs?
White pulp
12. Getting sick is an example of which form of immunity?
Naturally acquired active immunity
13. What is an example of artificially induced passive immunity? Antidotes
If this had been active, the answer would have been vaccine.
Vaccine - inject Ags so your body will form Abs
vs.
Antidote - inject Abs directly (usually an emergency)
Vaccine is an "active process" where your body has to work hard to fight those Ags in order to make those Abs.
vs.
Antidote is a "passive process" where your body is given the Abs (no need to make them).
Both are artificial because this involves a needle.
14. Which type of cell displays MHC I protein on the cell surface?.
cytotoxic T cell or CD 8
15. Which type of cell displays MHC II protein on the cell surface
Helper T or CD 4 cell
MCH I - displayed on all somatic cells except the immune cells
MHC = major histocompatibility complex
name tag
MHC I --> civilians (somatic cells that cannot fight back)
vs.
MHC II --> soldiers (immune cells that can fight back, e.g. WBC or phagocyte or APC)
The reason why this is so important is the outcome of foreign Ag expression is very different.
1. MHC I - displays foreign Ag
--> Cytotoxic T cell (CD cell) shows up to destroy foreign cell or infected cell
vs.
2. MHC II - displays foreign Ag
--> Helper T cell (CD 4 cell) shows up to activate both T and B cells to fight this Ag
Class I MHC protein = MHC I (on somatic cells)
and
Class II MHC protein = MHC II (on immune cells)
Fig 22-19 - We are looking at a somatic cell.
How do we know that here?
What is the major evidence that this is a somatic cell (yellow)?
The major giveaway is that you see MHC I on this yellow cell. So it must be a somatic cell (not an immune cell).
Do you all truly understand this?
The second best answer is a cytotoxic T cell communicates with the MHC I on the somatic cell.
In Fig 22-19, we are looking at a somatic cell with MHC I displaying a foreign Ag and is now in communication with a
cytotoxic T cell (CD 8 cell).
Steps involved:
1. Ag recognition --> Cytotoxic T cell recognizes something is wrong
2. Co-stimulation --> communicate both ways to confirm presence of foreign Ag
3. Activation and division --> make more active cytotoxic T cells and memory T cells
4. Destruction of target cells --> kill the infected cell or the pathogen itself
a. Perforin
b. Cytokines
c. Lymphotoxin
Notice this time the yellow is display MHC II with a foreign Ag.
So this yellow cell is an "immune cell". So even if the Ag is foreign, this immune cell will not be killed because it knows how
to fight back.
1. Ag recognition --> Helper T cell recognizes something is wrong
2. Co-stimulation --> communicate both ways to confirm presence of foreign Ag
3. Activation and division --> make more active helper T cells and memory T cells
4. Activate both T and B cells to fight this foreign Ag
Notice that the immune cell with MHC II remains intact and alive.
B cells need to be "sensitized" before they undergo stimulation.
Since you all said that Ch. 23 - Respiration is ok with you, I will just show you Quiz 3 study guide.
The hardest part of Ch. 23 is knowing which muscles are involved in both passive and active breathing and whether they
contract or relax.
Victoria Ying
2:09 PM
regular font --> primary muscles
bold font --> accessory muscles (only used during active breathing)
Do you understand how to sort this information from the study guid
Are there any questions about Ch. 22 - Lymphatics and Ch. 23 - Respiration?
I will e-mail you Final Exam (50 questions) that covers Ch. 22 - Lymphatics, Ch. 23 - Respiration, Ch. 18 - Endocrine
System, and Ch. 26 - Urinary System.
Final will be due on Sun, Dec 5 at 10 p.m.