Organ Systems
Form meets Function
The organ systems of
the human body and
other vertebrates help
to maintain balance and
perform a variety of
functions.
The Body Worlds exhibit
of preserved human
bodies and allows
visitors to view the
amazing human body in
never before seen ways.
This unit will introduce
the major parts and
functions of each of the
body systems.
Image
Levels of Organization
 The levels of organization in a
multicellular organism include cells,
tissues, organs, and organ systems
 Cells the basic unit in living things;
specialized cells perform particular
functions (EX heart cell)
 Tissues are groups of similar cells that
perform a single function
(EX connecting muscle to bone)
 An Organ is a group of tissues that work
together to perform a complex function
(EX Eyes for sight)
 An organ system is a group of organs that
perform closely related functions
(EX the digestive system)
Image
Cells




Cells can be specialized (have a certain function
Function = job
Function is related to the cell structure
Structure = how parts of the cell are put
together
 Shape
 Material it’s made from
 Structure of a brain cell is different from muscle
cell
 Can you tell which cells are neurons, fat,
leukocytes, bone (osteocytes, skeletal muscle,
smooth muscle, cardiac muscle, cubodial (roll
up to make tubes)
Types of Tissues
 There are four basic types of tissues in the human body
 Epithelial tissue - Glands and tissues that cover interior and
exterior body surfaces
 Connective tissue - Provides support for the body and connects
its parts
 Nervous tissue - Transmits nerve impulses throughout the body
 Muscle Tissue - Along with bones, helps the body to move
Examples of Epithelium Tissue
Examples of Connective Tissue
Examples of
Nervous Tissue
Examples of Muscle Tissue
Organs
Organ Systems
 There are 11 organ systems of the human body that work
together to maintain homeostasis in the body
 Homeostasis is the process by which organisms keep internal
conditions relatively stable despite changes in external
environments











Muscular system
Skeletal system
Nervous system
Circulatory system
Respiratory system
Endocrine system
Lymphatic/Immune system
Digestive system
Excretory system
Integumentary system
Reproductive system
Image
Muscular System
 Function:
 Works with the skeletal system to
produce voluntary movement;
helps to circulate blood and move
food through the digestive system
 Major Structures:
 Skeletal Muscles – usually
attached to bones and help with
voluntary movement
 Smooth Muscles – found in the
walls of hollow structures
(stomach, blood vessels,
intestines) and NOT under
voluntary control
 Cardiac Muscles – found only in
the heart and NOT under
voluntary control
Image
 Works Closely With: the skeletal
system to move the body, with the
help of signals from the nervous
system
Organization of the Skeletal Muscle
Muscle Anatomy
If you were to take one
whole muscle and cut
through it, you would
find the muscle is
covered in a layer of
connective muscle
tissue known as the
Epimysium that
protects the muscle
from friction against
other muscles and
bones.
Organization of the Skeletal Muscle
Surrounding the muscle fiber is the
Sarcolemma = fibers cell membrane then the
Sarcoplasm = cells cytoplasm, containing
Glycogen, Fats and Mitochondria for energy.
Each muscle fiber itself contains cylindrical
organelles known as Myofibrils.
Myofibrils made up of
bundles of Actin and
Myosin proteins which
run the length of the
muscle fiber and are
Important in muscle
contraction known as
the sliding filament theory.
Muscles in Action
SKELETAL SYSTEM
Three types of
Skeletal systems
are:
Exoskeleton
Endoskeleton
Hydrostatic
Skeletal System
 Function:
 Supports the body; locomotion of
voluntary muscles, protection of
organs; helps to maintain calcium
levels; provides a site for blood
cell formation
 Major Structures:
 Bones, joints, cartilage,
ligaments, tendons
 Types of Cells:
 Osteoblasts – build and produce new bone
 Osteoclasts – break down bone
 Bone Marrow – within the hollow center of bones, produces red
and white blood cells and platelets
 Works Closely With: the 206 bones in the adult body works with the
muscular system to move the body
Image
Work on your worksheets!
Skeletal System
In the outline of the
Homo sapien on your
Skeletal Systems page
draw and label the
following structures:
clavicle, femur, fibula,
humerus, patella, pelvis,
radius, ribs, scapula,
skull, sternum, tibia and
ulna.
Nervous System
 Function: Recognizes and
coordinates the body’s responses to
changes in its internal and external
environment
 Major Structures: Central Nervous
System = brain & spinal cord and
Peripheral Nervous System = cranial
nerves, ganglia and spinal nerves
 Types of Cells: Neurons – send the
messages of the nervous system
though electrical impulses
 Works Closely With: sensory
receptors and the five senses (sight,
sound, smell, taste, and touch) to
interpret stimuli from the
environment
Image
Central and Peripheral Systems
Central Nervous System (CNS)
consists of the brain and spinal cord.
- sensory information goes down the dorsal roots
- motor information goes down the ventral roots to
the muscles and glands
dorsal root ganglion (ganglia, plural)
"Gray matter" in middle = cell bodies
"White matter" surrounding = insulated axons
Central and Peripheral Systems
Peripheral Nervous System
(PNS) receives signals from the spinal cord
and transmits the message by way of
peripheral nerves. Peripheral nerves in the
cervical region serve the neck and arms; those
in the thoracic region serve the trunk; those in
the lumbar region serve the legs; and those in
the sacral region serve the bowels and bladder.
The PNS consists of
somatic nervous system that connects
voluntary skeletal muscles with cells
specialized to respond to sensations, such
as touch and pain
autonomic nervous system is made of
neurons connecting the CNS with internal
organs. It is divided into
- sympathetic nervous system which
prepares the body for action: fight or
flight
-parasympathetic nervous system
helps to restore the body, build up
energy & supplies needed in the
future, and relax
Typical Neuron and Synapse
Typical Neuron and Synapse cont
Read the
excerpts from
the article
entitled
“Neuron” and
very briefly
describe the
four steps of a
nerve impulse
down a neuron.
Reflex Arc
• A reflex arc is the pathway
that a nerve reflex, such as
the knee jerk reflex, follows.
A tap on the knee stimulates
sensory receptors,
generating a nerve signal.
The signal travels along a
nerve to the spinal cord. In
the spinal cord, the signal is
transmitted from the
sensory nerve to a motor
nerve. The motor nerve
sends the signal back to a
muscle in the thigh. The
muscle contracts, causing
the lower leg to jerk upward.
The entire reflex occurs
without involving the
brain.
Place the number next to the FUNCTION
correct part
Occipital Lobe
Center for processing visual and spatial information
Medulla
Temporal Lobe
the end of the spinal chord is where many involuntary actions, heart beating,
breathing, digestion, are regulated
Center for processing auditory and temporal (time-related) information
Limbic System
Manages the transition between sleep and arousal
Thalamus
Involved in the processing of emotion and strong drives like sex, fear and hunger.
Cerebral Cortex
A region of high neuron concentration, divided into the following lobes, (one on each
side of the brain).
Various functions, including processing of physical sensation and new movements.
Bottom of parietal lobe contains olfactory bulb, = taste/smell
Helps control what information reaches the frontal lobes, regulates flow of consciousness
and attention
Where information for performing learned movements are stored.
Parietal Lobe
Hypothalamus
Cerebellum
The Frontal Lobes
Cerebo-spinal Fluid
Where thought occurs. Both are centers for memory, learning, problem-solving, feeling,
awareness, and decision-making. The left side = analytical; right side = "openended" understanding and thinking
Produced by glands in the brain to act as a protective cushion.
Circulatory System
Image
 Function - Brings oxygen, nutrients, and
hormones to cells; fights infection;
removes cells wastes; helps to regulate
body temperature
 Major Structures - Heart, vascular system
made up of blood vessels (arteries &
veins), blood
 Heart Video
 Types of Cells  Red blood cells – transport O2 & CO2
 White blood cells – fight infection
 Platelets – allow blood to clot and
stop bleeding
 Works Closely With:
 the respiratory system in gas exchange;
 digestive system to pick up and carry nutrients to the cells of the body
 the excretory system to filter and clean the blood
 the endocrine system to deliver hormones
Close Up of a Blood Vessel
Image
 The connective blood vessels of the body carry the cells of
the circulatory system
 The vessels can sometimes become blocked with plaque
(fatty buildup) shown in yellow
Sounds of the Circulatory System
Image
 The heart muscle contacts an average of 72
times per minute, sending blood throughout
the body through a series of blood vessels.
 Sound File
Respiratory
System
Function:
Provides oxygen needed for
cellular respiration and removes
excess carbon dioxide from the body
Major Structures:
Upper respiratory tract –
the nasal cavity, pharynx and larynx
Lower respiratory tract – the
trachea, bronchi and lungs
Key Parts:
Nose and nasal cavities, mouth,
larynx, trachea, bronchi and their
branches, diaphragm, and the alveoli
 Works Closely With:
the circulatory system in gas exchange and the muscular system for
inhalation and exhalation.
Parts of the
Respiratory System
 With each breath, air enters our
body through the air passageways
and fills up our lungs.
 Within each lung, the tiny
alveoli are surrounded by
blood vessels and oxygen
and carbon dioxide diffuse
in and out of the vessels.
Image
Digestive System
 Function:
 Converts foods into simpler
molecules that can be used
by the cells of the body;
absorbs nutrients; eliminates
fecal matter
 Major Structures:
 Mouth, pharynx, esophagus,
stomach, small and large
intestines, rectum
 Key Parts:
 Villi – folded structures within
the walls of the intestines
which allow for nutrient
exchange
 Works Closely With: circulatory
system to deliver nutrients to the
cells of the body
Image
Close UP of
Digestive Villi
 The villi projections allow as much of
the nutrients in the digestive system to
move in to the circulatory system,
providing energy for cells.
Image
Digestive Enzymes
The pH in the human digestive tract
varies greatly. The pH of saliva is
usually between 6.5 - 7.5. After we
chew and swallow food it enters the
stomach, pH 4.0 - 6.5. This is where
"predigestion" occurs. Just before
leaving the stomach, near the pyloric
sphincter, hydrochloric acid (HCI) and
pepsin are secreted reaching a pH
between 1.5 - 4.0. Food mixes with
these juices and enters the small
intestine where the pH changes to 7.0 8.5. This is where 90% of the nutrients
are absorbed and the waste products
are passed out through the large
intestine, pH 4.0 - 7.0.
Excretory System
 Function:
 Eliminates urine and other byproducts from the body while
maintaining homeostasis
 Major Structures:
 Skin, lungs, kidneys, ureters,
urinary bladder, urethra
 Key Parts:
 Kidneys – remove waste
products from the blood
 Bladder – collects urine (wastes
filtered through the kidney)
 Works Closely With: the circulatory
system to filter and clean the blood
Image
phagocytic
leukocyte
Fighting the
Enemy Within!
Immune / Lymphatic
System
AP Biology
lymphocytes
attacking
cancer cell
lymph
system
2007-2008
Why an immune system?
 Attack from outside



lots of organisms want you for lunch!
animals are a tasty nutrient- & vitamin-packed meal
animals must defend themselves against invaders (pathogens)
 Viruses, bacteria, Fungi, Protists
 Attack from inside

cancers (abnormal body cells)
 Function
 protects body from disease
 collects fluid lost from blood vessels &
returns it to the circulatory system
Mmmmm,
What’s in your
lunchbox?
AP Biology
Lymph system
Works closely with the
circulatory system to fight infection
and collect excess fluids
Major
Structures:
lymph vessels
(intertwined amongst blood vessels)
AP Biology
lymph node
Development of Red & White blood cells
Red blood cells
inflammatory
response
fight
parasites
Leukocytes
Lymphocytes
AP Biology
White blood cells
develop into
macrophages
short-lived phagocytes
60-70% WBC
Innate vs Acquired Immunity
INNATE
•
•
•
present before any
exposure to pathogens
effective from the time
of birth
largely nonspecific and
slow to respond to
specific microbes
External: Skin, Mucous
membranes, Secretions
Internal: Phagocytic Cells,
Antimicrobial proteins,
Inflammatory response
and Natural Killers
AP Biology
ACQUIRED
• develops only after exposure to
microbes, abnormal body cells,
toxins or other foreign
substances
• highly specific because
Lymphocytes (white blood
cells) produce two types of
immune responses
Humoral: cells derived from B cells
secrete defensive proteins call
antibodies
Cell-mediated: T cells directly
destroy infected body and cancer
cells, and foreign tissue
Lines of defense
 1st line: Non-specific barriers

broad, external defense
 “walls & moats”

skin & mucous membranes
 2nd line: Non-specific patrols

broad, internal defense
 “patrolling soldiers”

leukocytes = phagocytic WBC
 3rd line: True immune system

specific, acquired immunity
 “elite trained units”

lymphocytes & antibodies
 B cells & T cells
AP Biology
Bacteria & insects
inherit resistance.
Vertebrates
acquire immunity.
1st line: Non-specific External defense
 Barrier
 skin
Lining of trachea:
ciliated cells & mucus
secreting cells
 Traps
 mucous membranes, cilia,
hair, earwax
 Elimination
 coughing, sneezing, urination,
diarrhea
 Unfavorable pH
 stomach acid, sweat, saliva, urine
 Lysosome enzyme
 digests bacterial cell walls
 tears, sweat
AP Biology
2nd line: Non-specific patrolling cells
bacteria
 Patrolling cells & proteins

attack pathogens, but don’t
“remember” for next time
 leukocytes
 phagocytic white blood cells
 macrophages, neutrophils,
natural killer cells
AP Biology
 complement system
 proteins that destroy cells
 inflammatory response
 increase in body temp. (fever)
 increase capillary permeability
 attract macrophages
macrophage
yeast
Inflammatory response (local non—
specific trigger when tissue is damaged)
AP Biology
3rd line: Acquired (active) Immunity
B cell
 Specific defense with memory

lymphocytes
 B cells
 T cells

antibodies
 immunoglobulins
 Responds to…

antigens
 cellular name tags
 specific pathogens
 specific toxins
 abnormal body cells (cancer)
AP Biology
Y
Y
Y
Y

multi-chain proteins
binding region matches molecular shape of antigens
Y
each antibody is unique & specific
tagging “handcuffs”
Y

Y
Y
Y

Y

Y
Y
 Proteins that bind to a specific antigen
Y
Y
Antibodies
Y
Y
Y
 “this is foreign…gotcha!”
Y
antigenbinding site
on antibody
antigen
Y
Y
variable
binding region
Y
Y
AP Biology
each B cell
has ~50,000
antibodies
bone marrow
Lymphocytes
 B cells


mature in bone marrow
humoral response system
 “humors” = body fluids
 attack pathogens still circulating
in blood & lymph


produce antibodies
Types: Plasma and Memory cells
 T cells


mature in thymus
cellular response system
 recognize and attack invading cells

AP Biology
Types: Helper, Killer and Memory T Cells
Vaccinations
 Immune system exposed
to harmless version of pathogen

stimulates B cell system to produce
antibodies to pathogen
 “active immunity”
rapid response on future exposure
 creates immunity
without getting
disease!

 Most successful
against viruses
AP Biology
April 12, 1955
Jonas Salk
 Developed first vaccine

against polio
 attacks motor neurons
Albert Sabin
1962
oral
vaccine
AP Biology
1914 – 1995
Polio epidemics
1994:
Americas polio free
AP Biology
Passive immunity
 Obtaining antibodies from another
individual

maternal immunity
 antibodies pass from mother to baby across
placenta or in mother’s milk
 critical role of breastfeeding in infant health
 mother is creating antibodies against pathogens baby
is being exposed to
 Injection
injection of antibodies
 short-term immunity (rabies shot)

AP Biology
HIV & AIDS
 Human Immunodeficiency Virus

virus infects helper T cells
 helper T cells don’t activate rest of immune system:
killer T cells & B cells
 also destroys helper T cells
 AIDS: Acquired ImmunoDeficiency Syndrome
infections by opportunistic
diseases
 death usually from
“opportunistic” infections

 pneumonia, cancers
AP Biology
HIV infected T cell
Endocrine System
 Function:
 Controls growth, development,
and metabolism; maintains
homeostasis
 Major Structures:
 Hypothalamus, pituitary, thyroid,
parathyroid, adrenals, pancreas,
and gonads (ovaries in females, &
testes in males)
 Key Parts:
 Hormones – chemicals released in
one part of the body and travel to
affect other parts
 Works Closely With: the nervous
system which controls the release of
hormones and the circulatory system
to deliver them
Image
GLAND: Hypothalamus
LOCATION: Ventral part of the forebrain.
HORMONE: Secretes releasing or
inhibiting hormones that act directly on
the tissues of the pituitary gland.
FUNCTION: It is the control center for
many autonomic functions of the
peripheral nervous system. Connections
with structures of the endocrine and nervous systems enable the
hypothalamus to play a vital role in maintaining homeostasis. As a
limbic system structure, it influences various emotional responses.
GLAND: Pituitary
LOCATION: Bean sized structure that dangles
on a slender stalk of tissue at the base of the
skull. The gland is divided into two parts:
anterior and posterior
HORMONE: Secretes hormones that directly
regulate many body functions and controls
the actions of several other endocrine glands.
FUNCTION:
Posterior Oxytocin
Contraction of uterus and releases milk
Pituitary Antidiuretic (Vasoperssin) Tells kidneys to reabsorb water
Growth
Protein synthesis and growth in bones
Prolactin
Production of Breast Milk
Anterior FSH (Follicle-stimulating) Stimulates production of ova and sperm
Pituitary LH (Luteinizing)
Ovaries and testes
TSH (Thyroid-stimulating) Stimulates the thyroid gland
ACTH (Adrenocorticotropic) Tells adrenal cortex to secrete glucocorticoids
GLAND: THYROID &
PARATHYROID
LOCATION: Base of neck and wraps around the upper part of the trachea.
HORMONE: Thyroid Hormone (Triiodothyronine (T3) and Thyroxine (T4)
Calcitonin
FUNCTION: Stimulate and maintain Basal Metabolic Rate (BMR), which is
the amount of energy the body uses
Lowers blood calcium level
LOCATION: The four glands are found on the back
surface of the thyroid gland.
HORMONE: Parathyroid hormone
FUNCTION: Raises blood calcium level
GLAND: Pancreas
LOCATION:
Just behind the stomach;
upper left quadrant
HORMONE:
Insulin
Glucagon
FUNCTION:
Cluster of cells called islets of Langerhans
contain beta cells which secrete insulin
and lower blood glucose levels and
alpha cells which secrete glucagon and
raise blood glucose levels
GLAND:
LOCATION:
HORMONE:
Adrenal
Two pyramid-shaped structures that
sit on top of thekidneys; each gland
has an outer part, adrenal cortex,
inner part, adrenal medulla
Epinephrine and norepinephrine
Glucocorticoids and Mineralocorticoids
FUNCTION:
Adrenal Epinephrine
Medulla (adrenalin) and
Norepinephrine
(noradrenalin)
Adrenal Aldosterone
Cortex (Glucocorticoids
Mineralocorticoids
Raise blood glucose level,
increase metabolic activities,
constricts some blood vessels;
prepares the body for “fright,
fight or flight”
Raise blood glucose levels
Promote reabsorption of Na+
and excretion of K+ in kidneys
and an
GLAND:
LOCATION:
HORMONE:
FUNCTION:
Gonads
Female – inside pelvis cavity
Male – outside pelvic cavity
Androgens, Estrogen,
Progesterone
Production of gametes and
secretion of sex hormones
Testes
Androgen
(Testosterone)
Support sperm formation, promote
development and maintenance of male
secondary sex characteristics
Ovaries
Estrogen
Stimulate uterine lining growth,
promote development and
maintenance of female secondary sex
characteristics
Progesterone
Promotes uterine lining growth
Image
Integumentary System
 Function:
 Protection is the most important
function. It serves as a barrier against
infection and injury
 Major Structures:
 Skin, hair, and nails
 Key Parts:
 Epidermis – outer layer of skin
 Dermis – inner layer of skin
 Hair – protects the skin and filters
particles
 Nails – extension of the skin, grow 3
mm per day on average
 Works Closely With: nervous system
through the five senses
Integumentary System cont.
The Skin is the human body's Largest Organ.
The word INTEGUMENT comes from a LATIN word that means to COVER.
FIVE Other Functions of the Integumentary System
1. Serves as a barrier against infection and injury.
2. Helps to regulate body temperature.
3. Removes waste products from the body.
4. Provides protection against UV radiation from the sun.
5. Produces vitamin D.
The skin contains sensory receptors through
which sensations such as pressure, heat, cold,
and pain are transmitted to the nervous system.
The skin is made up of two main layers –
the epidermis and the dermis. Beneath the
dermis is a subcutaneous layer of fat.
1. The outer most layer of skin , composed of
five layers and four types of cells.
2. Most of the cells of the Epidermis undergo
rapid cell division (MITOSIS) and are
shed or washed away once every 14 to
28 days.
3. As new cells are produced, they push
older cells to the surface of the skin. The
older cells become flattened, lose their
cellular contents and begin making
Keratin.
4. Keratin is a tough fibrous protein and
forms the basic structure of hair, nails
and calluses. In animals it forms horns,
scales, feathers, and quills.
5. The Epidermis contains melanocytes, cells
that produce melanin, a dark brown
pigment.
6. There are no blood vessel in the
epidermis, which is why a small scratch
will not cause bleeding.
EPIDERMIS
DERMIS
1. Second layer of skin composed of living cells.
2. Connective tissue layer composed of collagen and elastic fibers, fibroblasts,
macrophage and fat cells, hair follicles, glands, nerves and blood vessels.
4. Beneath the Dermis is the
Hypodermis,
(Subcutaneous layer), a
layer of fat and loose
connective tissue that
insulate the body and
acts as an energy reserve.
5. The Dermis contains TWO
major types of GLANDS:
Sudiferous (sweat)
and Sebaceous (oil) Glands.
6. Oil Glands are connected by
Tiny Ducts (Exocrine Glands)
to Hair Follicles. Sebum coats the surface of the skin and the shafts of hair,
preventing excess water loss and lubricating and softening the skin and hair.
HAIR
1. Hair is produced by cells at the base of structures called Hair Follicles.
Hair protects and insulates the body.
2. Hair Follicles are tube-like pockets of epidermal cells that extend into
the dermis. Tiny Muscle fibers attach to Hair Follicles contract and pull hair
upright when you are cold or afraid, producing Goose Bumps.
3. Individual hairs are actually
large columns of dead cells
filled with Keratin.
4. Rapid cell growth in the
Hair Root causes hair to
grow longer. Hair gets its
color from Melanin.
5. Hair Follicles are in close
contact with Sebaceous
Glands.
NAILS
Nails grow from an area of rapidly dividing cells know as the Nail Matrix
or Nail Root and is located near the tips of the fingers and toes.
Nails rest on a bed of tissue filled with
blood vessels, giving the nails a
pinkish color.
Nails grow at a rate of 0.5 to 1.2 mm per
day, with fingernails growing faster
than toenails.
Place the number on the diagram
on your worksheet
Reproductive Systems
 Function:
Produces reproductive cells; in
females, nurtures and protects
developing embryo
 Major Structures:
Testes, epididymis, vas deferens,
urethra, and penis (in males);
ovaries, Fallopian tubes, uterus,
vagina (in females)
fetus at 8 weeks
 Types of Cells:
Sperm Cells – male reproductive cells created in the male reproductive
system
Ova – female egg cells created in the female reproductive system
 Works Closely With: endocrine system to receive sex hormones
 Slideshow of Conception
Scrotum - fold of the body wall which aids the
reproductive process in different ways:
Testes develop in the
abdomen and
descend into the
scrotum just before
birth. This is
important since
sperm can not
develop at normal
body temperature and
must be kept
approximately 2° C
lower.
Fig. 46.9
 Ovaries are the female gonads.
 Located in the abdominal cavity and enclosed in a
tough protective capsule.
 Attached by mesentery to the uterus.
 Each ovary contains follicles.
 The remaining
female reproductive
structures are:
 Cervix: neck of the
uterus, that opens
into the vagina.
Vagina: thinwalled chamber
that forms the
birth canal.