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Study Guide FINAL

 KNOW the basics for each tissue type. They will help you answer most of the questions (Mescher Ch 2-10)
 Pay attention to recurring themes, e.g. absorptive cells
 Review pathways – we’ve studied a lot of them, e.g. circulatory pathways
 MAs
 There will be some “Jeopardy” type questions. I give you the answer; you give me the question
 Put content together. Can something you learned in one chapter apply to another chapter?
 A theme – serous membranes
 A theme – abrupt changes in epithelium
 A theme – folded membranes that secrete protective fluids
 A theme – blood-tissue barriers
 A theme – metaplasia
 A theme – phenotype changes
 A theme – problems in viewing histology, microscopic imaging of special tissues, unique characteristics
we’ve talked about
 A theme – epithelial cell junctions
o https://www.studocu.com/en/document/university-of-texas-at-austin/human-microscopic-and-grossanatomy/summaries/revision-notes-and-gross-human-microscopic-anatomy-final-exam-studyguide/164550/download/revision-notes-and-gross-human-microscopic-anatomy-final-exam-studyguide.pdf
 Stem cells
 https://accessmedicine.mhmedical.com/content.aspx?bookid=1687&sectionid=109633268
 A theme – absorptive cells
 Cellular structure, plasma membrane MAs, cytockeleton, glycocalyx, special basement membranes
 Sensory receptors we have studied
 Nerve pathways, Visual pathways
 Circulatory pathways, special ones
 Pathway through the nephron, know the structures
 Hemorrhage was used as an example of activation of many different compensatory mechanisms in the body
o Reproductive pathways
 Metabolic pathways, e.g. renin, angiotensin, aldosterone system
o The testis
 Respiratory pathways and MAs
 Interactions between hormones and other systems, e.g. connective tissue, metabolism, cardiovascular reproductive
 Development of the embryo Clinical Correlations
o Similarities / differences in male/female reproductive tract structures
o Reproductive system MAs. Are there any that affect other systems
o Development of mature egg and sperm cells
o Hormonal regulation of the female menstrual cycle
o Be sure you know the general structures we have discussed in epithelia
 Similarities in muscles and nerves
 Osteogenesis and bone MAs
 Sarcomere banding patterns
 Excitation contraction coupling, how does movement occur?
 3 muscle types – similarities / differences?
 Special terminology in the nervous system
 Autonomic innervation of structures in the body, any new information here?
 Knee injuries
 One question about anaphylaxis
 Structures in hemopoiesis
A theme – serous membranes
What is the epithelium lining serious membranes? Simple squamous mesothelium
Examples of serous membranes in the body
o Pericardium
o Pleura
o Peritoneum
o Bowman’s capsule in the glomerulus of the kidney
o Tunica vaginalis
Serous membranes is a mesothelial tissue that lines certain internal cavities of the body, forming a smooth,
transparent, two-layered membrane lubricated by a fluid derived from serum
The pericardial cavity (surrounding the heart), pleural cavity (surrounding the lungs) and peritoneal cavity
(surrounding most organs of the abdomen) are the three serous cavities within the human body.
The serosa is a thin layer of loose connective tissue, rich in blood vessels, lymphatics, and adipose tissue, with a simple
squamous covering epithelium or mesothelium.
In the abdominal cavity, the serosa is continuous with mesenteries, thin membranes covered by mesothelium on both
sides that support the intestines.
Mesenteries are continuous with the peritoneum, a serous membrane that lines that cavity.
In places where the digestive tract is not suspended in a cavity but bound directly to adjacent structures, such as in
the esophagus, the serosa is replaced by a thick adventitia, a connective tissue layer that merges with the surrounding
tissues and lacks mesothelium.
The intraperitoneal organs are the stomach, spleen, liver, bulb of the duodenum, jejunum, ileum, transverse colon, and
sigmoid colon.
The retroperitoneal organs are the remainder of the duodenum, the cecum and ascending colon, the descending colon,
the pancreas, and the kidneys.
The epicardium corresponds to the visceral layer of the pericardium, the membrane surrounding the heart.
Where the large vessels enter and leave the heart, the epicardium is reflected back as the parietal layer lining the
 During heart movements, underlying structures are cushioned by deposits of adipose tissue in the epicardium and
friction within the pericardium is prevented by lubricant fluid produced by both layers of serous mesothelial cells.
Pericardial sac
 Fibrous pericardium provides the strength to the pericardial sac and prevents the heart from overfilling.
 Parietal layer of the serous pericardium is fused to the inner aspect of the fibrous pericardium; helping the heart beat
in a frictionless environment.
 Visceral layer of the serous pericardium (epicardium) is not a layer of the pericardial sac but rather the outermost
layer of the heart. It is continuous with the parietal layer.
The lung’s outer surface and the internal wall of the thoracic cavity are covered by a serous membrane called the
The membrane attached to lung tissue is called the visceral pleura and the membrane lining the thoracic walls is the
parietal pleura.
The two layers are continuous at the hilum and are both composed of simple squamous mesothelial cells on a thin
connective tissue layer containing collagen and elastic fibers.
The elastic fibers of the visceral pleura are continuous with those of the pulmonary parenchyma.
The narrow pleural cavity between the parietal and visceral layers is entirely lined with mesothelial cells that
normally produce a thin film of serous fluid that acts as a lubricant, facilitating the smooth sliding of one surface over
the other during respiratory movements.
A theme – abrupt changes in epithelium
At the junction between the esophagus and stomach there is an abrupt change to simple cuboidal epithelium
A theme – folded membranes that secrete protective fluids
A theme – blood-tissue barriers
A theme – metaplasia
 Change in epithelium due to something that occured (heavy smoking).
 Changing from pseudostrafied to stratified
 Loss of cilia, can’t move mucus through or foreign objects out.
 Increase of goblet cells → Increase mucus but no cilia to help move it out.
 This is why smokers cough a lot and have bronchitis
 In chronic bronchitis, common among habitual smokers, the number of goblet cells in the lining of airways in
the lungs often increases greatly. This leads to excessive mucus production in areas where there are too few
ciliated cells for its rapid removal and contributes to obstruction of the airways. The ciliated pseudostratified
epithelium lining the bronchi of smokers can also be transformed into stratified squamous epithelium by
What diseases cause metaplasia of the epithelium?
 Barrett’s esophagus
o caused normally by acid reflux or GERD (gastrointestinal-reflux-disease)- when stratified squamous
epithelium is replaced by columnar epithelium (metaplasia)
 Stratified squamous epithelium  columnar epithelium
 Chronic Bronchitis
o bronchial tubes are inflamed → leading to a production of excess mucus produced by excess goblet cells
(where there is not enough cilia to remove it) → coughing and difficulty breathing.
o Metaplasia of epithelium (pseudostratified ciliated columnar → stratified squamous)
A theme – phenotype changes
Phenotype changes in connective tissue cells – a “theme”
 Something makes something a phenotype change if it is reversible.
 The cells that have these changes are:
o Fibroblast  Fibrocytes
 The active fibroblasts have more abundant and irregularly branched cytoplasm
 Its nucleus is large, ovoid, euchromatic, and has a prominent nucleolus
 The cytoplasm has more RER and a well-developed golgi apparatus
 The quiescent cell, fibrocyte, is smaller than the active fibroblast, is spindle shaped with fewer
processes and much less RER and contains a darker, more heterochromatic nucleus
 Activated by growth factors
o Osteoblast  Osteoclasts
 Play a role in deposition of inorganic matrix (hydroxyapatite)
 Osteocalcin
 Phosphate filled vesicles
 Osteoblasts’ cytoplasm are basophilic because of presence of many RER
 Osteocytes are endocrine cells and signal changes in mechanical load
 Osteocytes don’t just sit there
o Chondroblasts  Chondrocytes
o Macrophages
 Remove cell debris, neoplastic cells, bacteria, and other invaders. Macrophages are also important
antigen presenting cells required for Activation and specification of lymphocytes
 When macrophages are stimulated by injection of foreign substances or by infection, they change
their morphological characteristics and properties, becoming activated macrophages
 They show an increased capacity for phagocytosis and intracellular digestion. Activated macrophages
exhibit enhanced metabolic and lysosomal enzyme activity.
 Also release enzymes for ECM breakdown, and growth factors or cytokines that help regulated
immune cells
 When stimulated enough, they can increase in size and fuse to form multinuclear giant cells found in
pathological conditions
o Microglia
 Microglia are in macrophages family of protein
 When activated by damage or invaders, microglia retract their processes, proliferate, and assume the
morphological characteristics of antigen presenting cells
o Parietal cells
 Stomach acid (HCl) is produced by parietal cells in the gastric glands
 Active parietal cells have an intracellular canaliculus
o Satellite cells in skeletal muscle
o Phage adipocytes
 Osteocytes are NOT a phenotype change
Cells of connective tissue
Fibroblasts: key cells in connective tissue proper and originate from mesenchymal cells
Maintain most of tissues’ extracellular components
Synthesize and secrete collagen and elastin
Immature/Active = fibroblast with eurochromatic nuclei
Mature/Inactive = fibrocyte with heterochromatic nuclei
Targets of many family proteins called growth factors that influence cell growth and differentiation
Stimulated by locally released growth factors, cell cycling, and mitotic activity resume when tissue
requires addition fibroblasts to repair a damaged organ
Myofibroblasts: fibroblasts involved in wound healing and have a well developed contractile function
and enriched with a form of actin found in smooth muscle cells.
Adipocytes: Fat cells found in connective tissue of many organs
Large mesenchymal derived cells that are specialized for cytoplasmic storage of lipid as neutral fats,
and not really for heat.
Serves to cushion and insulate the skin and other organs
Macrophages: highly developed phagocytic ability and specialized in turnover protein fibers and removal of dead cells,
tissue debris, or other particulate material
Abundant at sites of inflammation
Oval/kidney shaped nucleus
Well developed Golgi and many lysosomes
Derive from monocytes (bone marrow precurser cells)
Important role in repair and inflammation
Under bad conditions, these cells use local proliferation of microphages and recruit more monocytes
from the blood
Distributed through body and present in stroma of most organs. Have different names for different
- Kupffer cells → Liver
- Microglial cells → Central Nervous System
- Langerhans cells → Skin
- Osteoclasts → Bone
Highly important for uptake, processing, and presentation antigens for lymphocyte activation
h. Mast Cells: oval or irregularly shaped cells of connective tissues filled with basophilic secretory granules
Metachromasia: can change the color of some basic dyes from blue to purple to red
Poorly preserved so cells are hard to see on slides
Function in localized released to respond to local inflammation, innate immunity, and tissue repair
Molecules released:
 Heparin: sulfated GAG that acts locally as anticoagulant
 Histamine: promotes increased vascular permeability and smooth muscle contraction
 Serine proteases: activate various mediators of inflammation
 Eosinophil and neutrophil chemotactic factors: attract those leukocytes
 Cytokines: polypeptides directing activities of leukocytes and other cells of immune system
 Phospholipid: precursers that are converted to prostaglandins, leukotriens, and other
important lipid mediators of inflammatory response
Numerous near small blood vessels
Immediate hypersensitivity reactions: release of certain chemical mediators stored in mast cells that
promotes the allergic reaction known as this
e. Plasma Cells: lymphocyte derived, antibody producing cells
Relatively large ovoid cells that are rich in RER and large Golgi near nucleus
Nucleus is spherical and weirdly placed
Average life span is 10-20 days.
f. Leukocytes: other white blood cells besides macrophages and plasma cells
Derived from circulating blood cells
Leave blood by migrating between the endothelial cells of venules to enter connective tissue
Increases greatly during inflammation which is a vascular and cellular defensive response to injury
or foreign substances including pathogenic bacteria or irritating chemical substances
Inflammation begins with local release of chemical mediators from various cells, the ECM, and blood
plasma proteins. Act on local blood vessels, mast cells, macrophages, and other cells to induce events
like inflammation
Function in connective tissue for only a few hours or few days then undergo apoptosis
Fibers of Connective Tissue
a. Collagen: family of proteins that have ability to form various extracellular fibers, sheets, and networks. Key element of
all connective tissues and epithelial basement membranes and external laminae of muscle and nerve cells
Fibrallar collagens (types I,II, and III): polypeptide subunits to form large fibrils and form structures like
tendons, organ capsules, and dermis
Network or sheet forming collagen (type IV: subunits produced by epithelial cells and are major structural
proteins of external laminae and epithelial basal laminae
linking/anchoring collagens: short collagens that link fibrillar collagens to one another. Type VII binds with
type IV and anchors basal lamina to underlying reticular lamina in basement membranes
Collagen synthesis: specialty of fibroblasts.
b. Reticular fibers:found in delicate connective tissue, notably the immune system and is Type 3
Argyrophilic: characteristically stained black after impregnation with silver salts
Reticular fibers produced by fibroblasts occur in reticular lamina of basement membranes and surround
adipocytes, smooth muscle and nerve fibers, and small blood vessels
Bone marrow, spleen, and lymph nodes
c. Elastic FIbers: thinner than type I collagen and form spparse networks with collagen bundles in may organs, especially
those for bending and stretching
Ex: stroma of lungs, wall of large blood vessels, etc
Elastic lamelle: sheets of elastin in large blood vessels
Fibrilin: composite of elastic fibers that form a network of microfibrils embedded in larger mass of cross
linked elastin. All secreted from fibroblasts
A theme – problems in viewing histology, microscopic imaging of special tissues, unique characteristics we’ve talked about
Fixation procedures and types of microscopy – what’s good for what?
 Tissue preparation:
o Fixation- small pieces of tissue are placed in solutions of fixatives that preserve by cross-linking proteins and inactivating
degradative enzymes
 Good for avoiding tissue digestion by enzymes inside the cell- to preserve cells and tissue structure
o Embedding- paraffin-infiltrated tissue is placed in a small mold with melted paraffin and allowed to hardenfacilitates
o Sectioning- paraffin block is trimmed to expose the tissue for sectioning on a microtome
o Staining- dyes stain tissue components selectively behaving like acidic or basic compounds and forming electrostatic (salt)
linkages with ionizable radicals of molecules in tissues
 Cells components such as nucleic acids with a net negative (anionic) charge stain more readily with basic dyes and are
termed basophilic
 Basic dyes include blues and purples- Hematoxylin
o Tissue components that react with these dyes are: DNA and other acidic structures  Cationic cell components more readily
stain with acidic dyes are termed acidophilic
 Acidic dyes include pink- Eosin
o Tissue components that react with these dyes are: mitochondria, collagen, and secretory granules
 Types of microscopy
o Light microscopy: interaction of light with tissue components- they reveal and study tissue features
 Bright-field Microscopy: stained preparations are examined by means of ordinary light that passes through a
o  Includes mechanisms to move and focus the specimen
o 
good for objects smaller than 0.2 μm (ribosomes, membranes, or actin filaments), structures such as
mitochondria might be seen as one object if they are less than 0.2μm apart.
Fluorescence Microscopy: Tissue is shined with UV light and the emission is in the visible part of the spectrum.
o  Microscope has a special filter that selects rays that are of a certain wavelength
o  Coupling compounds: adding a fluorescence to a molecule that is usually associated with something
allows for identification of structures under a microscope
o Identification of antibodies in immunohistologic staining
Phase-contrast microscopy: provides physical images from transparent objects
o  Good for studying unstained tissue sections
o 
Difference Interference Microscopy:
 3D image of living cells
 Confocal Microscopy: point light source to avoid a reduction of contrast and to allow high resolution and a sharp
o  Good because it greatly improves resolution
o  Allows for the construction of a 3D image
 Polarizing Microscopy: allows for recognition of stained or unstained structures made of highly-organized
o  Appear as bright structures against a dark background
o  Used for highly oriented molecules such as cellulose, collagen, microtubules, and actin filaments.
o Electron microscopy: interaction of tissue components with beams of electrons
 Transmission Electron Microscopy: permits resolution ~ 3nm
Applies ONLY to isolated macromolecules or particles
Can add heavy metals to improve contrast resolution
Cryofracture and freezing allow for TEM study without fixation or embedding
o Useful in the study of membrane structure
 Scanning Electron Microscopy: high resolution of cells, tissues, and organs
 Presents a 3D view
o Biopsies: tissues samples removed during surgery or routine medical procedures
A theme – epithelial cell junctions
Stem cells
A theme – absorptive cells
Absorptive cells in the small intestine
Enterocytes, the absorptive cells, are tall columnar cells, each with an oval nucleus located basally.
The apical end of each enterocyte displays a prominent ordered region called the striated (or brush) border.
Ultrastructurally the striated border is seen to be a layer of densely packed microvilli covered by glycocalyx through
which nutrients are taken into the cells.
Each microvillus is a cylindrical protrusion of the apical cytoplasm containing actin filaments and enclosed by the cell
Microvilli, villi, and the plicae circulares all greatly increase the mucosal surface area in contact with nutrients in the
lumen, which is an important feature in an organ specialized for nutrient absorption.
Ingested fats are emulsified by bile acids to form a suspension of lipid droplets from which lipids are digested by
lipases to produce glycerol, fatty acids, and monoglycerides (1).
The products of hydrolysis diffuse passively across the microvilli membranes and are collected in the cisternae of the
smooth ER, where they are resynthesized as triglycerides (2).
Processed through the RER and Golgi, these triglycerides are surrounded by a thin layer of proteins and packaged in
vesicles containing chylomicrons of lipid complexed with protein (3).
Chylomicrons are transferred to the lateral cell membrane, secreted by exocytosis, and flow into the extracellular
space in the direction of the lamina propria, where most enter the lymph in lacteals (4).
Know the structure of an absorptive cell and parts of the body in which we have studied them
 Epithelial Tissue
o Long invaginations of the basal membrane outline regions with mitochondria
o Interdigitations from neighboring cells are also present laterally
o Immediately below the microvilli are pinocytotic vesicles, which may fuse with lysosomes as shown or mediate
transcytosis by
secreting their contents at the basolateral membrane
o Immediately below the basal lamina is a capillary that removes water resorbed across the epithelium
Large intestine
o Absorbs water and electrolytes and forms indigestible material into feces
o Tubular intestinal glands are lined by goblet and absorptive cells (with a small number of enteroendocrine cells) o
Colonocytes (absorptive cells)
 Irregular microvilli and dilated intercellular spaces indicating active fluid absorption o Appendix has little or no absorptive
 Small intestine
o Plicae circulares (formed by the mucosa and submucosa)
Increases the absorptive area
Lined by dense covering fingerlike projections called villi
 Internally, each villi contains microvasculature, lamina propria, CT, and lymphatics called lacteals o Villi are covered with a
simple columnar epithelium composed of absorptive enterocytes and goblet cells
 At the apical surface of each villus, we have dense microvilli which serve to increase greatly the absorptive surface of the
 Epididymis
o Stereocilia- apical process restricted to absorptive epithelial cells lining the Epididymis and the proximal part of the ductus
Increase the surface are and facilitate absorption
Much longer and less motile than microvilli
Nerve pathways, Visual pathways
Nerve pathways to skeletal muscle
NEED TO KNOW what are they, how do they work, what are the structures?
● Corticospinal Pathway: indirect pathway
● Corticobulbar Pathway: direct pathway
o Synapse at medulla
● Indirect Motor Pathways
In Central Nervous System, the cell bodies are in nucleus and the tracts are bundle of axons
Corticospinal tracts
The corticospinal tract is a white matter motor pathway starting at cerebral cortex that terminates on lower motor neurons
and interneurons in the spinal cord.
● It is a motor pathway in peripheral nervous system and is an indirect pathway.
o Innervated by the nerves in the PNS which are bundles of axons
o Cell bodies are ganglion
o 2 neurons in series with 2 synapses
o It is efferent (travels away from the brain) and causes movement
● It controls movement of the limbs and trunk.
● They become myelinated usually in the first two years of life
● The primary purpose of the corticospinal tract is for voluntary motor control of the body and limbs. However,
connections to the somatosensory cortex suggest that the pyramidal tracts are also responsible for modulating
sensory information from the body
● Corticospinal tracts has 2 neurons and 2 synapses
o Primary motor cortex is where it starts
▪ It is precentral gyrus of the brain
▪ Signal at the primary motor cortex (left side of
body) synapses into upper motor neuron.
▪ Synapse at anterior gray matter
o Upper motor neurons begin in cerebral cortex on left
side of body.
o Goes all the way down to synapse at anterior grey
matter of spinal chord.
▪ All motor pathway synapse in anterior grey
matter and sensory synapse in posterior grey
o Descends through white matter of brain.
o Then travels to brain stem, then to midbrain (still on
left side of the brain)
o Then travels to medulla oblongata
▪ The anterior upper neuron remains in anterior
▪ The lateral tract travels across the other side
(right side)
o Then travels down to spinal cord in their respective
tracts, experience decussation in spinal cord, synapse
to lower motor neurons at the right anterior horn and
travel to skeletal muscle on the right side of the body
▪ Synapse between skeletal muscle and motor neuron causes contraction
● Summary: upper motor neurons start at precentral gyrus  synapse at anterior grey matter of spinal cord → lower
motor neuron go from anterior grey matter of spinal cord out to the skeletal muscle.
o Neuromuscular junction action potential
● Anterior pathway vs lateral Pathway in the corticospinal tract
o Anterior tract has decussation (crossing over) in spinal cord and multipolar neuron
o Lateral tract has decussation at the medulla.
Optic nerve pathways
Temporal visual field is processed from nasal retina
Nasal vision is processed from temporal retina
Zonular Fibers: change the shape of the lens (relax and tightening (contracting))
Attached to ciliary muscle: Ciliary muscle contraction loosens zonular fibers and vice versa
The right visual field is encoded on the left visual cortex
The left visual field is encoded on the right visual cortex
Optic Chiasm: when the nerves cross
● where the nerves of the nasal visual field and the temporal visual retina waves cross; they become contralateral
● the temporal portion axons don't cross at the optic chiasm and remain ipsilateral
● The nasal right field and temporal left field combine (and vice versa) and extend back
● If cut in the middle (optic chiasm), tell what sides you can’t see from.
○ If you cut in the middle you won’t be able to see from the right temporal visual field and left temporal visual
Light pathways in eyes
● Light travels straight through the retina until it hits the back of the pigmented layer (rods and cones) and turns 180
degrees back towards the inner portion of the eye
● rods and cones take light information and transduce light rays into electrical currents
○ photoreceptors that send electrical signal
Sensory receptors we have studied
Circulatory pathways, special ones
Think about the level of oxygenation in vessels of different circulatory beds
In most blood flow, oxygenated blood flows from arteries to arterioles, capillaries, venules, and veins.
There are 3 portal systems in the human body.
o Anterior pituitary gland: blood flows from arteriole to 1st capillary bed, venule, 2nd capillary bed, venule,
o Hepatic portal vein: deoxygenated blood flows from veins of the digestive tract to hepatic portal vein, venules,
hepatic sinusoid, 2nd capillary bed, venules, central vein
o Kidneys: oxygenated blood flows from the afferent arterioles, glomerulus (1st capillary bed), efferent
arteriole, 2nd capillary bed (peritubular arteries for juxtamedullary nephron and vasa recta for the cortical
o Bone marrow
Circulation of blood through the lungs is different. Deoxygenated blood flows from the right ventricle to the pulmonary
arteries, arterioles, capillaries for gas exchange, venules, pulmonary veins, left atrium.
Pathway through the nephron, know the structures
Functions of the nephron:
o Filtration- water and solutes of the blood leave the vascular space and enter the lumen of the nephron
o Secretion (tubular)- substances move from epithelial cells of the tubules into the lumens, usually after uptake from the
surrounding interstitium and capillaries
o Reabsorption (tubular)- substances move from the tubular lumen across the epithelium into the interstitium and surround
 Structures in a nephron
o Renal Corpuscle
An initial dilated part enclosing a tuft of capillary loops and the site of blood filtration, always located in the cortex
Glo erular Bo a ’s
Filtrate is formed in the
o Proximal Tubule
Long convoluted part, located entirely in the cortex
A shorter straight part that enters the medulla
Reabsorb water and electrolytes
Ions that were not filtered in the corpuscle undergo secretion into
the filtrate
o Loop of Henle (or nephron loop)
In the medulla
Thin descending limb
Thick ascending limb
Further adjust the salt content
of the filtrate
 Transport sodium and
chloride ions out of the tubule against a concentration
o Distal tubule
Consisting of thick straight part
ascending from the loop of
Henle back into the cortex and a convoluted part completely in the cortex
Reabsorption of water and sodium regulated by ADH and aldosterone
Juxtaglomerular apparatus
 Macula densa cells communicate with juxtaglomerullar cells via gap junctions about the sodium levels in the distal tubule
o Reninangiotensinogenangiotensin Iangiotensin IIvasoconstriction, thirst, aldosterone secretion
o Connecting tubule
 Short, final part linking the nephron to collecting ducts
Hemorrhage was used as an example of activation of many different compensatory mechanisms in the body
Reproductive pathways
Metabolic pathways, e.g. renin, angiotensin, aldosterone system
The testis
Respiratory pathways and MAs
Interactions between hormones and other systems, e.g. connective tissue, metabolism, cardiovascular reproductive
Development of the embryo Clinical Correlations
Similarities / differences in male/female reproductive tract structures
Reproductive system MAs. Are there any that affect other systems
Development of mature egg and sperm cells
Hormonal regulation of the female menstrual cycle
Be sure you know the general structures we have discussed in epithelia
Similarities in muscles and nerves
Osteogenesis and bone Mas
Bone development that occurs by intramembranous ossification or endochondral ossification
Expect more concepts related to bone MAs
1. Osteosarcoma: cancer arising in osteoprogenitor cells since cancer arising directly from bone cells is so uncommon
2. Osteocytes MA: loading in boanes has been increased or decreased and signaling cells to adjust ion levels and
maintain the adjacent bone matrix accordingly. Lack of exercise leads to decreased bone density
3. Osteopetrosis: dense, heavy bones. Overgrowth and thickening of bones that cause anemia and loss of white blood
4. Osteoporosis: found in immobilized patients and postmenopausal women. Bone resorption exceeds bone formation
5. Osteomalacia: mineralization is impaired, deficient calcium
6. Osteitis fibrosa cystica: increased osteoclast activity results in removal of bone matrix and fibrous degeneration
7. Osteogenesis imperfecta: brittle bone disease. Osteoblasts produce deficient amounts of type I collagen due to genetic
8. Rickets: bone matrix does not calcify normally and the epiphyseal plate can become distorted by the normal strains of
body weight and muscular activity
9. Pituitary dwarfism: lack of growth hormone during the growing years
10. Gigantism: excess of growth hormone causing excessive growth of the long bones
11. Rheumatoid arthritis: chronic inflammation of the synovial membrane that cause thickening of this connective tissue
and stimulates the macrophages to release collagenases and other hydrolytic enzymes
Cellular structure, plasma membrane MAs, cytockeleton, glycocalyx, special basement membranes
Cellular Structure
Plasma Membrane MAs ?????
Plasma membranes in tissues treated with osmium and viewed with TEM
Inner and outer layers with space in between (perinuclear space)
With the transmission electron microscope (TEM) the cell membrane—as well as all cytoplasmic membranes—may
exhibit a trilaminar appearance after fixation in osmium tetroxide; osmium binds the polar heads of the phospholipids and the
oligosaccharide chains, producing the two dark outer lines that enclose the light band of osmium-free fatty acids.
The nuclear envelope contains two phospholipid bilayers, separated by a perinuclear space. (There are seven bands
because the inner and outer nuclear membrane contain the three layers of the phospholipid bilayer and are separated by the
perinuclear space)
know order of the seven layers
Outer phosphate layer of the outer membrane
the outer fatty acid layer
the inner phosphate layer of the outer membrane
the perinuclear space
the outer phosphate layer of the inner membrane
the inner fatty acid layer
the inner phosphate layer of the inner membrane
Structures in the cytoskeleton
Intermediate filaments: which apply to which tissue
Look at pics and see what structures you can see
The cytoplasmic cytoskeleton is a complex array of:
 Microtubules
 Microfilaments
 Intermediate filaments
Cytoskeleton helps:
 Determining the shapes of cells
 Plays important role in the movement of organelles and cytoplasmic vesicles
 Allow the movement of entire cells
Intermediate filament proteins with particular biological, histological, or pathological importance include following:
 Keratins (Cytokeratins) : diverse family of acidic and basic isoforms that compose heterodimer subunits of
intermediate filaments in all epithelial cells
o Produce filaments with different chemical and immunologic properties for various functions.
o Intermediate filaments of keratins form large bundles (tonofibrils) that attach to certain junction between
epithelial cells.
 In skin epidermal cell, keratins accumulate - keratinization, produce an outer layer of nonliving cells
that reduces dehydration.
 Ex. nails and other hard protective structures of skin
 Vimentin: the most common class III intermediate filament protein and is found in most cells derived from embryonic
o Desmin: found in almost all muscle cells
o Glial fribrillar acidic protein (GFAP): found especially in astrocytes, supporting cells of central nervous system
 Neurofilament: proteins of three distinct sizes make heterodimers that form the subunits of the major intermediate
filaments of neurons.
 Lamins: a family of seven isoforms present in the cell nucleus, where they form a structural framework called the
nuclear lamina just inside the nuclear envelope
Major classes and representatives of intermediate filament proteins, their sizes and locations.
Glycocalyx: delicate cell surface coating created by glycolipids and glycoproteins of membrane that have covalently attached
oligosaccharide chains exposed at surface
 Function:
o Cell to Cell signaling
o Antigen binding
o Cell adhesion
o Response to hormones
Special Basement Membranes
Specialized surfaces on all epithelial cell surgace
Basement membrane
1. The basal surface of all epithelia rests on a thin extracellular, felt-like sheet of macromolecules
referred to as the basement membrane , a semipermeable filter for substances reaching epithelial
cells from below.
2. The basal surface of all epithelia rests on a thin extracellular, felt-like sheet of macromolecules
referred to as the basement membrane, a semipermeable filter for substances reaching epithelial
cells from below.
Ex. Kidney Renal glomerulus and its surrounding tubules.
3. Basal Lamina TYPE IV
Upper layer of basement membrane
Composed of two primary structures: collagen and laminin
Laminin binds Type IV collagen and integrins (hemidesmosomes)
Very secure
Maintains cell polarity, and helps localize endocytosis, signal transductions, and other activities.
4. Reticular Lamina TYPE III & TYPE VII
Below Basal Lamina
Contains type III collagen bound to the basal lamina by anchoring fibrils of type VII collagen
Very loose
Synthesized by the connective tissue of the lamina propria
5. Hemidesmosomes
Bind the basal surface of the epithelial cell to the underlying basal lamina
Anchoring junction to the basal lamina
Core protein of integrin
Sarcomere banding patterns
Excitation contraction coupling, how does movement occur?
3 muscle types – similarities / differences?
Special terminology in the nervous system
Central Nervous System:
o Spinal Cord:
 Nuclei
 Clusters of cell bodies that comprise gray matter
 Bundles of processes of neurons that comprise white matter
 Tracts
o Brain:
 Cerebrum and Cerebellum
Peripheral Nervous System
o Cranial and Spinal Nerves
 Ganglia
 Clusters of cell bodies that comprise gray matter
 Nerves
 Bundles of processes neuron that comprise white matter
Autonomic innervation of structures in the body, any new information here?
Autonomic innervation of sweat glands
o  Eccrine sweat glands are innervated by cholinergic sympathetic, post-ganglionic neurons
o  Apocrine sweat glands are innervated by adrenergic nerves
What cells undergo phenotype changes? What are the changes?
 Cancer cells undergo phenotype changes
Autonomic innervation of the heart including neurotransmitters and receptors
 Both parasympathetic and sympathetic neural components innervate the heart
o Ganglionic nerve cells and nerve fibers are present in the regions close to the SA and AV nodes where they affect
heart rate and
rhythm, such as during exercise and emotional stress
 Stimulation of the parasympathetic division (vagus nerve) slows the heartbeat, whereas sympathetic
nerve accelerates activity of the
 Between fibers of the myocardium are afferent free nerve ending that register pain, such as the
discomfort called angina pectoris that
occurs when partially occluded coronary arteries cause local oxygen deprivation
Sympathetic innervation
o Adrenergic receptors with norepinephrine neurotransmitters  Norepinephrine causes vasoconstriction
 Parasympathetic innervation (vagus nerve)
o Muscarinic receptors with Ach neurotransmitters
 Ach causes vasodialation
Knee injuries
Common types of knee injuries and knee anatomy
ACL prevents hyperextension
PCL prevents hyperflexion
If you are walking uphill, PCL prevents hyperflexion
Major bones associated with knee joint: Femur, Patella, Tibia, Fibula
Knee joint, tendons, muscles, joints, arteries, meninci, ligament
Most important Medical Application: Knee joint
Patellofemoral Pain Syndrome (PFPS)
● An overuse type of injury with chronic characteristics
● Anterior knee pain that is felt underneath the patella (kneecap)
● Common among young women and active individuals
● Exacerbated by activities such as stair climbing, squatting, or
sitting for a prolonged period of time with the knees in a flexed
position (Earl et al. 2005)
● Normal process of knee flexion and extension is involved with movement of the patella via the quadriceps tendon inward
the trochlear groove of the femur inferiorly and superiorly respectively (Guney et al., 2016). In normal pattern of
movement and during knee flexion and extension, there is no contact between the ridge of the patella which is covered by
a layer of soft tissue (located on its posterior surface) and the medial and lateral condyles of the femur.
● What are the main causes for maltracking of the patella?
o Clinically Measured Static Alignment
o Dynamic Malalignment
o Abnormal Muscle Activation
PFPS causes:
● Clinically measured static alignment
● Dynamic malalignment
● Static Alignment
● Abnormal muscle activation
PFPS rehab: Physical therapy to strengthen the medial and lateral quadriceps
Knee joint injuries: Ligament Ruptures i.e. ACL
Rehab: ACL Reconstruction Surgery
○ Tendons are removed from the semitendinosus and gracillus muscles
○ The graft is used as an artificial ACL
○ Screws and staples hold the graft in place
○ Copers: people who can recover from ACL tears without needing surgery
One question about anaphylaxis
Structures in hemopoiesis
Mature blood cells have a relatively short life span and must be continuously replaced with new cells from precursors
developing during hemopoiesis.
o In the early embryo these blood cells arise in the yolk sac mesoderm.
o In the second trimester, hemopoiesis (also called hematopoiesis) occurs primarily in the developing liver,
with the spleen playing a minor role.
o Skeletal elements begin to ossify and bone marrow develops in their medullary cavities, so that in the third
trimester marrow of specific bones becomes the major hemopoietic organ.