Transcript LACC Pathophysiology Seminar Series: Anatomy & Physiology Review By Greg Gonsalves Associate Professor of Anatomy & Physiology.

LACC Pathophysiology Seminar
Series: Anatomy & Physiology
Review
By Greg Gonsalves
Associate Professor of Anatomy &
Physiology
I. Life is based on many structural levels
Levels of animal structure:
 Atoms
and molecules
 Cells
 Tissues
 Organs
 Organ
systems
 Organism: May consist of a single cell or a
complex multicellular organism.
Levels of Structural Organization in an Animal
TISSUES:
 Most
animal cells are organized into tissues.
 Cooperative
unit of very similar cells that perform
a specific function.
 Tissue
 Cells
comes from Latin word meaning “weave”.
of tissues may be held together by:
 Fibers
 Glue-like
 Plasma
 Tissue
substance
membrane structures
structure is related to its function.
TISSUES:
There are four main types of animal
tissue:
1. Epithelial
2. Connective
3. Muscle
4. Nervous
1. Epithelial Tissue
 Cells
are tightly fitted together in continuous
layers or sheets.
 Cover outside of body (skin), line organs and
internal body cavities (Mucous membranes of
digestive, respiratory, and reproductive systems).
 Tight packaging allows tissue to act as a barrier
to protect against mechanical injury, infection,
and fluid loss.
 Two surfaces:
 Free
surface: Exposed to air or fluid.
 Bottom surface: Attached to underlying tissues by a
basement membrane, a dense layer of protein and
polysaccharides.
1. Epithelial Tissue
Can be classified based on two criteria:
A. Number of layers:
 Simple:
One layer.
 Stratified: Several layers
B. Shape of cells:
 Squamous:
Flat cells.
 Cuboidal: Cube shaped cells
 Columnar: Column shaped cells
Example:
 Simple
squamous epithelium
 Stratified columnar epithelium
Epithelial Tissue Covers and Lines the Body and its Parts
A. Simple squamous
(Lung air sacs)
D. Statified squamous
(Lining esophagus)
B. Simple cuboidal
(Kidney tubes)
C. Statified columnar
(Lining intestine)
1. Epithelial Tissue
Some epithelial tissues, such as mucous membranes,
absorb and secrete chemical solutions.
 Mucous membranes:
 Digestive
tract epithelium (mucous membranes)
secretes mucus and digestive enzymes.
 Respiratory tract epithelium secretes mucous that
helps trap dust particles before they reach the lungs.
2. Connective Tissue
 Relatively
few cells surrounded by large amounts
of nonliving material (matrix).
 Cells secrete the matrix, which can be solid,
liquid, or gelatinous.
 Diverse functions. Mainly bind, support, and
connect other tissues.
 Six types of connective tissue in humans:
1. Loose Connective Tissue: Most widespread connective
tissue in vertebrates. Loose matrix with fibers,
packing material. Attaches skin to muscles, binds and
holds tissues and organs in place.
2. Adipose (fat): Pads and insulates body. Energy
storage.
Connective Tissue Binds and Provides Support
A. Loose Connective Tissue
B. Adipose Tissue
C. Blood
D. Fibrous Connective Tissue
E. Cartilage
F. Bone
Types of connective tissue in humans (Continued):
C. Blood: Fluid matrix (plasma) has water, salts, and
proteins. Red and white blood cells.
D. Fibrous Connective Tissue: Matrix of densely packed
collagen fibers. Strong and nonelastic. Found in:
• Tendons: Attach muscles to bones.
• Ligaments: Attach bone to bone.
E. Cartilage: Rubbery matrix with collagen fibers.
Found on end of bones, nose, ears, and between
vertebra.
F. Bone: Supports the body of most vertebrates. Solid
matrix of collagen fibers and calcium, phosphate, and
magnesium salts. Bone is harder than cartilage, but not
brittle because of collagen.
3. Muscle Tissue
 Most
abundant type of tissue in most animals.
Accounts for two-thirds (2/3) of human weight.
 Specialized for contraction. Made up of long cells
that contract when stimulated by nerve impulses.
 Muscle cells have many microfilaments made up
of actin and myosin.
 Muscle contraction accounts for much of energy
consuming work in animals.
 Adults have a fixed number of muscle cells.
Weight lifting doesn’t increase number of muscle
cells, only their size.
3. Muscle Tissue
There are three types of muscle tissue:
A. Skeletal (striated) muscle : Attached to bones by
tendons.
Responsible for voluntary movements.
B. Cardiac muscle: Forms contractile tissue of heart.
Not under voluntary control.
C. Smooth muscle: Found in walls of digestive tract,
bladder, arteries, uterus, and many internal organs.
Responsible for peristalsis and labor contractions.
Contract more slowly than skeletal muscle, but can
remain contracted longer.
Not under voluntary control.
Three Types of Muscle
B. Cardiac muscle
A. Skeletal muscle
C. Smooth muscle
4. Nervous Tissue
 Senses
stimuli and transmits signals from one
part of the animal to another.
 Controls the activity of muscles and glands, and
allows the animal to respond to its environment.
 Neuron: Nerve cell. Structural and functional
unit of nervous tissue. Consists of:
body : Contains cell’s nucleus.
 Dendrite: Extension that conveys signals towards the
cell body.
 Axon: Extension that transmits signals away from the
cell body.
 Cell
 Supporting
neurons.
cells: Nourish, protect, and insulate
Nervous Tissue Forms a Communication Network
Organs are made up of different tissues
Organ:
Several tissues that act as a unit
and together perform one or more
biological functions.
 Perform
functions that component tissues can’t
carry out alone.
Example: The heart is an organ made up of:
• Muscle Tissue: Contraction
• Epithelial Tissue: Lines heart chambers to prevent
leakage and provide a smooth surface.
• Connective Tissue: Makes heart elastic and
strengthens its walls and valves.
• Nervous Tissue: Direct heart contractions.
Organs are Made of Several Different Tissues
Animals Regulate their Internal
Environment
Homeostasis:
 Internal
“Steady state”.
environment of animal remains fairly
constant despite changes in the external
environment.
 Control systems maintain internal conditions
within a range in which life’s metabolic
activities can occur.
 Homeostasis is a dynamic state resulting from
changes in the outside environment and
internal control mechanisms that oppose such
changes.
Homeostatic Mechanisms Counteract Changes
in External Conditions
Animals Regulate their Internal
Environment
Homeostasis:
 Maintained
by negative feedback mechanisms.
 A change in one condition (e.g.: low body
temperature), results is a response that
counteracts that change (e.g.: shivering, etc.).
 Internal conditions regulated by negative
feedback:
•
•
•
•
Body temperature (Normal range: 97 - 100oF)
Salt concentration
pH
Blood levels of sugar, calcium, oxygen, etc.
Negative Feedback as Homeostatic Mechanism
Body Temperature is Regulated by Homeostasis
Major Organ Systems in Mammals
 Digestive
system
 Respiratory system
 Circulatory system
 Cardiovascular
 Lymphatic
 Excretory
and Immune system
system
 Endocrine system
 Reproductive system
 Nervous system
 Muscular system
 Skeletal system
 Integumentary
1. Digestive System
Components: Mouth, salivary glands, throat,
esophagus, stomach, intestines, liver, gallbladder,
pancreas, rectum, and anus.
Functions:
 Ingest
and mechanically break down food.
 Digest food: Stomach and small intestine mainly.
 Absorb nutrients and water.
 Eliminate waste.
Homeostatic Roles:
 Supplies
energy for life’s activities.
 Supplies building blocks for macromolecules
Human Digestive System
Obesity
Obesity is often diagnosed by using using a
body mass index (BMI).

BMI = w
h2



W = weight in kilograms
H = height in meters
Obesity in childhood is due to an increase in
both the size and the # of adipocytes.
 Obesity defined as BMI > 30.
 Healthy weight as BMI between 19 – 25.

2. Respiratory System
Components: Nose, throat, larynx, trachea,
bronchi, and lungs.
Functions:
 Exchange


gases with the environment:
Supplies blood with oxygen.
Disposes of carbon dioxide (waste product from cellular
respiration).
Homeostatic Roles:
 Regulates
blood pH.
 Regulates blood oxygen and carbon dioxide levels.
Blood Transports Gases Between Lungs and Tissue
Human Respiratory System
Components:
Nasal cavity, throat (pharynx), larynx (voice
box), trachea, bronchi, alveoli, and lungs.
Pathway of Inhaled Air:
 Nasal cavity
 Pharynx (Throat)
 Larynx (Voice Box)
 Trachea (Windpipe)
 Bronchi
 Bronchioles
 Alveoli (Site of gas exchange)
Exhaled air follows reverse pathway.
Blood Transports Gases Between Lungs and Tissue
Human Respiratory System
1. Nasal cavity: Air enters nostrils, is filtered by
hairs, warmed, humidified, and sampled for
odors as it flows through a maze of spaces.
2. Pharynx (Throat): Intersection where pathway
for air and food cross. Most of the time, the
pathway for air is open, except when we
swallow.
3. Larynx (Voice Box): Reinforced with cartilage.
Contains vocal cords, which allow us to make
sounds by voluntarily tensing muscles.



High pitched sounds: Vocal cords are tense, vibrate fast.
Low pitched sounds: Vocal cords are relaxed, vibrate slowly.
More prominent in males (Adam’s apple).
Human Respiratory System
4. Trachea (Windpipe): Rings of cartilage
maintain shape of trachea, to prevent it from
closing. Forks into two bronchi.
5. Bronchi (Sing. Bronchus): Each bronchus leads
into a lung and branches into smaller and
smaller bronchioles, resembling an inverted
tree.
6. Bronchioles: Fine tubes that allow passage of
air. Muscle layer constricts bronchioles.
Epithelium of bronchioles is covered with cilia
and mucus.


Mucus traps dust and other particles.
Ciliary Escalator: Cilia beat upwards and remove trapped
particles from lower respiratory airways. Rate about 1 to 3 cm
per hour.
Pulmonary Function Tests
 Assessed
by spirometry.
 Subject breathes into a closed system in
which air is trapped within a bell
floating in H20.
 The bell moves up when the subject
exhales and down when the subject
inhales.
Spirogram




Tidal volume:
Amount of air expired with each breath.
Vital capacity:
The maximum amount of air that can be forcefully exhaled after
maximum inhalation.
Table 16.3
Terms Used to Describe Lung Volumes and
Capacities
Term
Definition
Lung Volumes
The four nonoverlapping components of the total lung
capacity
Tidal volume
The volume of gas inspired or expired in an unforced
respiratory cycle
Inspiratory reserve volume
The maximum volume of gas that can be inspired during
forced breathing in addition to tidal volume
Expiratory reserve volume
The maximum volume of gas that can be expired during
forced breathing in addition to tidal volume
Residual volume
The volume of gas remaining in the lungs after a maximum
expiration
Lung Capacities
Measurements that are the sum of two or more lung
volumes
Total lung capacity
The total amount of gas in the lungs after a maximum
inspiration
Vital capacity
The maximum amount of gas that can be expired after a
maximum inspiration
Inspiratory capacity
The maximum amount of gas that can be inspired after a
normal tidal expiration
Functional residual capacity
The amount of gas remaining in the lungs after a normal
tidal expiration
Restrictive and Obstructive Disorders

Restrictive
disorder:
 Vital
capacity is
reduced.
 FVC is normal.

Obstructive
disorder:
 VC
is normal.
 FEV1 is reduced.
Hemoglobin helps transport CO2 and buffer blood
Hemoglobin is found in red blood cells
Functions:
 Transports
oxygen
 Transport carbon dioxide
 Helps buffer blood
As carbon dioxide is picked up from tissues it is
converted into carbonic acid:
CO2 + H2O <-----> H2CO3 <----> H+ + HCO3 Carbon
dioxide
Carbonic acid
Carbonate ion
Hemoglobin picks up most H + ions, so they don’t
acidify the blood.
Respiratory Acid-Base Balance
 Ventilation
normally adjusted to
keep pace with metabolic rate.
 H2CO3 produced converted to CO2,
and excreted by the lungs.
 H20
+ C02
H2C03
H+ + HC03-
Diseases of the Respiratory System

Respiratory rate: 10 to 14 inhalations/minute.

In one day, an average human:

Breathes 20,000 times

Inhales 35 pounds of air

Most of us breathe in air that is heavily
contaminated with solid particles, ozone, sulfur
oxide, carbon monoxide, nitrogen oxides, and many
other damaging chemicals.

Breathing contaminated air can cause a number of
diseases including asthma, bronchitis, emphysema,
and lung cancer.
Diseases of the Respiratory System
 Lung Cancer: Cancerous growth that invades
and destroys lung tissue. Very high fatality rate.
Symptoms include bloody sputum, persistent
cough, difficulty breathing, chest pain, and
repeated attacks of bronchitis or pneumonia.
Causes: Smoking (50% of all cases) and pollution
(radon, asbestos). Smokers are 10 times more
likely to develop lung cancer than nonsmokers.
Treatment: Surgery is most effective, but only
50% of all lung cancers are operable by time of
detection. Other treatments include radiation
and chemotherapy.
3. Cardiovascular System
Components: Blood, heart, arteries, veins, and
capillaries.
Functions:
 Exchange


gases with the respiratory system.
Supplies tissues with oxygen.
Removes carbon dioxide from tissues.
 Transports
materials (nutrients, hormones, etc.) inside
body.
 Defends against infection.
Homeostatic Roles:
 Provides
nutrients and removes waste materials from
tissues.
 Regulates body temperature, water and ion balance.
Human Cardiovascular System
1. Blood
Average Blood Volume: 4 to 6 liters.
Blood composition:
55% Plasma (fluid matrix of water, salts, proteins, etc.)
45% Cellular elements:

Red Blood Cells (RBCs): 5-6 million RBCs/ml of blood. Contain
hemoglobin which transport oxygen and CO2.

White Blood Cells (WBCs): 5,000-10,000 WBCs/ml of blood. Play a
essential role in immunity and defense. Include:


Lymphocytes: T cells and B cells

Macrophages (phagocytes)

Granulocytes: Neutrophils, basophils, and eosinophils.
Platelets: Cellular fragments. 250,000- 400,000/ml of blood.
Important in blood clotting.
Types of Blood Vessels
A. Arteries and Arterioles:
 Carry
 Have
blood away from heart to body.
high pressure.
 Have
thick muscular walls, which make them
elastic and contractile.
 Vasoconstriction:
Arteries contract:

Reducing flow of blood into capillaries.

Increasing blood pressure.
 Vasodilation:
Arteries relax:

Increasing blood flow into capillaries.

Decreasing blood pressure.
Types of Blood Vessels
Capillaries: Only blood vessels whose walls are
thin enough to permit gas exchange.
Blood flows through capillaries relatively slowly,
allowing sufficient time for diffusion or active
transport of substances across walls.
Only about 5 to 10% of capillaries have blood
flowing through them. Only a few organs
(brain and heart) always carry full load of
blood.
Blood flow to different organs is controlled by
precapillary sphincters of smooth muscle.
Types of Blood Vessels
Veins and Venules:
 Collect
blood from all tissues and organs and
carry it back towards heart.
 Have
low pressure and thin walls.
 Veins
have small valves that prevent backflow of
blood towards capillaries, especially when
standing. If the valves cease to work properly,
may result in:

Varicose veins: Distended veins in thighs and legs.

Hemorroids: Distended veins and inflammation of the rectal and
anal areas.
Red Blood Cell Antigens
ABO system:
 Major group of antigens of RBCs.

 Type
A:
 Only A antigens present.
 Type B:
 Only B antigens present.
 Type AB:
 Both A and B antigens present.
 Type O:
 Neither A or B antigens present.
Transfusion Reactions
 If
blood types do not match, the recipient’s
antibodies attach to donor’s RBCs and
agglutinate.
 Type O:
 Universal
donor.
 Recipient’s antibodies cannot agglutinate the donor’s
RBCs.
 Type AB universal recipient:
 Lack the anti-A and anti-B antibodies.
 Cannot agglutinate donor’s RBCs.
Rh Factor
 Another
group of antigens found on RBCs.
 Rh positive:
 Have
these antigens.
 Rh negative:
 Do not have these antigens.
 Significant
when Rh negative mother give
birth to Rh positive baby.
 At
birth, mother may become exposed to Rh positive
blood of fetus.
 Mother at subsequent pregnancies may produce
antibodies against the Rh factor.
Heart
Anatomical Features:
Hollow muscular organ, about the size of a human fist.
 Weighs less than one pound (10 ounces).
 Rests on diaphragm, near middle of thoracic cavity.
 Wall is composed of cardiac muscle covered by connective
tissue.

Pericardium: Membrane that surrounds entire heart and
contains a fluid which protects heart and decreases
friction.
Heart
Heart Chambers: Heart is divided into four
separate chambers. Both the left and the
right side of the heart have a(an):
 Atrium
(Plural atria): Smaller, superior
chambers. Receive blood from veins.
 Ventricle:
Larger, inferior chambers. Pump
blood into arteries.
Two sides of heart have different functions:
 Right
 Left
side: Pumps oxygen poor blood.
side: Pumps oxygen rich blood.
Pacemaker (Sinoatrial node): Specialized structure
that sends electrical impulses that causes both
atria and ventricles to contract.
Heart
Heart Valves: Heart has several valves made of
connective tissue, that prevent backflow of
blood as it circulates.
 Atrioventricular (AV) Valves: Close between
atria and ventricles


Right AV Valve: Connects right atrium to the right ventricle.
Left AV Valve: Connects left atrium to the left ventricle.
Semilunar Valves: Close as blood leaves the
ventricles and enters the arteries.
Heart murmur: Rushing, gurgling sound created
by backflow of blood due to damaged or
imperfect heart valves. Fairly common (10%
of healthy population). Most are
asymptomatic.

Heart Beat

Average 70 beats per minute.

100,000 beats every day.

Cardiac cycle about every 0.8 sec.

Diastole: Heart relaxes and blood flows into chambers (0.4 sec).

Systole: Heart contracts.

First atria (0.1 sec)

Then ventricles (0.3 sec)

Pumps about 8000 liters of blood/day.

Pacemaker (Sinoatrial node): Controls heart rate.



Regulated by nervous and endocrine systems.
Two heart beat sounds (“Lub-dupp”):

First sound: Ventricles contract, AV valves close.

Second sound: Heart relaxes, semilunar valves are closing.
Pulse: Arteries expand and contract with each heartbeat.
Pacemaker Controls Cardiac Rhythm
Blood Pressure
 Pressure
is highest in arteries; lowest in veins.
 “Blood
pressure” usually refers to arterial pressure.
 Usually
measured at brachial artery in arm.
 Two
measurements:
 Systolic
Blood Pressure: During heart contraction.
Normal systolic pressure is about 120 mm Hg.
(Range: 110-140 mm Hg).
 Diastolic
Blood Pressure: During heart relaxation.
Normal diastolic pressure is about 80 mm Hg.
(Range: 70-90 mm Hg)
Blood Pathway in Body


Right Side of Heart:

Right atrium receives oxygen poor blood from body.

Right ventricle pumps oxygen poor blood to lungs.
Left Side of Heart:

Left atrium receives oxygenated blood from lungs.

Left ventricle pumps oxygenated blood to body.
Blood Pathway:
Veins  Vena cava  Right atrium  Right
AV Valve (Tricuspid)  Right ventricle  Pulmonary Semilunar Valve 
Pulmonary arteries  Lungs  Pulmonary veins  Left atrium  Left AV
Valve (Bicuspid or Mitral Valve)  Left ventricle  Aortic Semilunar Valve
 Aorta  Arteries  Capillaries  Veins
Cardiovascular Disease

Number one cause of death in the U.S. and
industrialized nations.

Includes hypertension, strokes, heart attacks, and
congestive heart failure.

Most often caused by complications of:
Arteriosclerosis: A condition in which arteries
become blocked by calcium and lipid deposits
(plaque), losing their elasticity.
Heart Attack (Myocardial infarction-MI)
 Sudden
decrease in blood supply to the heart, due to a
clot or plaque in arteries.
 Death
of cardiac muscle resulting in insufficient blood
supply to rest of body.
 Heart
may stop beating altogether or suffer permanent
damage.
 Over
7.9 Million heart attacks every year in U.S. (2004)

Leading cause of death and disability

60% had no previous symptoms.

25% are not recognized when they occur.
Heart Attacks are Caused by Blocked
Coronary Arteries
Heart Attack (Myocardial infarction)
 Symptoms:
Chest pain, pressure, or tightness, sweating,
nausea, shortness of breath, dizziness, and fainting.
 Risk
factors:
Smoking
 High blood pressure
 High cholesterol
 High LDLs (low density lipoproteins)
 Diabetes
 Male gender
 Emotional stress
 Obesity
 Heredity
 Sedentary lifestyle

4. Lymphatic and Immune System
Components: Lymph, lymphatic vessels, bone
marrow, thymus, spleen, and lymph nodes.
Functions:
 Defends
against infection: bacteria, fungi, viruses, etc.
 Destruction of cancer and foreign cells.
 Synthesis of antibodies and other immune molecules.
 Synthesis of white blood cells.
Homeostatic Role:
 Returns
fluid and proteins that have leaked from
blood capillaries into tissues.


Up to 4 liters of fluid every day.
Fluid returned near heart/venae cavae.
Lymphatic and Immune Systems
Introduction
Resistance: Ability to ward off disease.
 Nonspecific
Resistance: Defenses that protect
against all pathogens.
 Specific
Resistance: Protection against specific
pathogens.
Susceptibility: Vulnerability or lack of
resistance.
Protection Against Invading Pathogens
1. First Line of Defense: Non-specific natural
barriers which restrict entry of pathogen.
Examples: Skin and mucous membranes.
2. Second Line of Defense: Non-specific defenses that
provide rapid local response to pathogen after it has
entered body.
Examples: Fever, phagocytes (macrophages and
neutrophils), inflammation, and interferon.
3. Third line of defense: Antigen-specific immune
responses, specifically target and attack invaders
that get past first two lines of defense.
Examples: Antibodies and lymphocytes.
Defenses Against Infection
The Immune Response Destroys Specific
Invaders
Antigen: Molecule that elicits an immune response.
“Antibody generating”.
 Microbial
antigens: Viral capsid, bacterial cell wall, etc.
 Nonmicrobial
antigens: Pollen, latex, food, etc.
Antibody: Protein found in blood plasma that
attaches to antigen and helps counteract its effects.
Vaccination or Immunization: Process in which
harmless forms of antigen or pathogen are
introduced into body to provoke an immune
response.
Diseases Caused by the
Immune System
 Ability
of immune system to tolerate
self-antigens while it identifies and
attacks foreign antigens that can be
deranged.
 Diseases caused by the immune system
can be grouped into 3 categories:
 Autoimmune
disease.
 Immune complex diseases.
 Allergy or hypersensitivity.
Autoimmunity
 Those
produced by failure in the
immune system to recognize and tolerate
self-antigens.
 Failure due to:
 An
antigen that does not normally circulate in the
blood may be exposed to the immune system.
 Thyroglobulin.
A
self-antigen that is otherwise tolerated may be
altered by combining with a foreign hapten.
 Thrombocytopenia.
Autoimmunity

Antibodies may be produced that are directed
against other antibodies.
 Rheumatoid

Antibodies produced against foreign antigens
may cross-react with self-antigens.
 Rheumatic

arthritis.
fever.
Self-antigens may be presented to the helper
T cells together with class-2 MHC molecules.
 Type
I diabetes.
5. Excretory (Urinary) System
Components: Kidneys, bladder, urethra, and
associated ducts.
Functions:
 Kidneys
remove nitrogen containing waste from blood.
 Urine with waste is temporarily stored in bladder.
 Excretion of urine.
Homeostatic Role:
 Regulates
water levels in body.

Removes excess water

Helps conserve water
Human Excretory System
Renal Acid-Base Regulation
Kidneys help regulate blood pH by
excreting H+ and reabsorbing HC03-.
 Most of the H+ secretion occurs across the
walls of the PCT in exchange for Na+.

 Antiport
mechanism.
Normal urine normally is slightly acidic
because the kidneys reabsorb almost all
HC03- and excrete H+.
 Returns blood pH back to normal range.

Reabsorption of






HCO3
Apical membranes are impermeable to HCO3-.
Reabsorption is indirect.
HCO3- combines with H+ to form H2C03, which is
catalyzed by carbonic anhydrase (ca) located in the
apical cell membrane of PCT.
As [C02] increases in the filtrate, ca forms H2C03.
H2C03 dissociates to HCO3- and H+.
Shunt HCO3- generated within tubule cell to
peritubular capillary.
Urinary Buffers
 Nephron
cannot produce a urine pH <
4.5.
 IN order to excrete more H+, the acid
must be buffered.
 H+ secreted into the urine tubule and
combines with HPO4-2 or NH3.
 HPO4-2 + H+
H2PO4-2
 NH3 + H+
NH4+
Diuretics



Increase urine volume excreted.
Increase the proportion of glomerular filtrate that is
excreted as urine.
Loop diuretics:


Thiazide diuretics:


Inhibit NaCl reabsorption in the DCT.
Ca inhibitors:


Inhibit NaCl transport out of the ascending limb of the LH.
Prevent H20 reabsorption when HC03- is reabsorbed.
Osmotic diuretics:

Increase osmotic pressure of filtrate.
6. Endocrine System
Components: Pituitary, adrenal, thyroid, thymus,
pancreas, ovaries, testes, and other ductless
glands.
Functions:
 Produce





hormones that regulate:
Blood chemistry: Levels of sugars, minerals, etc.
Reproduction
Growth
Metabolism
Digestion
Homeostatic Role:
 With
nervous system, regulates metabolism and blood
chemistry.
Human Endocrine System
Hormones

Regulatory
molecules secreted
into the blood or
lymph by endocrine
glands.


Lack ducts.
Carry hormone to
target tissue
where it produces
its effects.
Posterior Pituitary
 Also
called the neurohypophysis.
 Formed by downgrowth of the brain
during fetal development.
 Is in contact with the infundibulum.
 Nerve fibers extend through the
infundibulum.
Hypothalamic Control of
Posterior Pituitary

Hypothalamus produces:





ADH: supraoptic nuclei.
Oxytocin: paraventricular nuclei.
Hormones transported
along the hypothalamohypophyseal tract.
Stored in posterior
pituitary.
Release controlled by
neuroendocrine reflexes.
Anterior Pituitary
Master gland (also called adenohypophysis).
 Derived from a pouch of epithelial tissue
that migrates upward from the mouth.
 Consists of 2 parts:
 Pars distalis: anterior pituitary.
 Pars tuberalis: thin extension in contact with
the infundibulum.

Anterior Pituitary
 Trophic
Health
effects:
of the target glands, depends upon
stimulation by anterior pituitary for
growth.
High plasma hormone concentration
causes target organ to hypertrophy.
Low plasma hormone concentration
causes target organ to atrophy.
Growth Hormone (GH) - Somatotrophic
Hormone (STH)
 Increases Growth and Maintenance of
Organs by:
 stimulating
protein anabolism
 promotes fat catabolism (use of fat rather than sugars for
energy)

Abnormal Secretions of STH
 Giantism
-- hypersecretion during childhood (before
epiphyseal plates close)
 Acromegaly -- hypersecretion during adulthood
 Dwarfism -- hyposecretion during childhood
 Cachexia (Simmond's Disease) - hyposecretion during
adulthood causes premature aging and atrophy of organs
Thyroid Hormones
 Thyroid
gland located just below the
larynx.
 Thyroid is the largest of the pure
endocrine glands.
 Follicular cells secrete thyroxine.
 Parafollicular cells secrete calcitonin.
Parathyroid Hormone
 Parathyroid
glands embedded in the
lateral lobes of the thyroid gland.
 Only hormone secreted by the
parathyroid glands.
 Single most important hormone in the
control of plasma Ca++ concentration.
 Stimulated by decreased plasma Ca++
concentration.
Adrenal Glands
 Paired
organs that cap the kidneys.
 Each gland consists of an outer cortex
and inner medulla.
 Adrenal medulla:
Derived
from embryonic neural crest
ectoderm (sympathetic ganglia).
 Synthesizes
and secretes:
 Catecholamines
(mainly epinephrine but some
norepinephrine).
Adrenal Glands
 Adrenal
cortex:
Does
not receive neural innervation.
Must be stimulated hormonally.
Consists of 3 zones:
 Zona
glomerulosa:
• Aldosterone: regulate Na+ and K+ balance.
 Zona
fasciculata:
• Cortisol: regulate glucose metabolism.
 Zona
reticularis:
• Androstenedione and DHEA: supplement sex steroids.
Adrenal Medulla
 Innervated
 Increase
by sympathetic nerve fibers.
respiratory rate.
 Increase heart rate, cardiac output; and
vasoconstrict blood vessels, thus increasing
venous return.
 Stimulate glycogenolysis.
 Stimulate lipolysis.
Pancreas
Endocrine portion consists of islets of
Langerhans.
 Alpha cells secrete glucagon.

 Stimulus
is decrease in plasma glucose concentrations.
 Stimulates lipolysis.

Beta cells secrete insulin.
 Stimulus
is increase in plasma glucose concentrations.
 Promotes entry of glucose into cells.
Diabetes Mellitus

Type I (insulin-dependent) diabetes
Pancreas does not produce insulin
 T cells destroy pancreatic islets



Needs daily insulin injections
Type II (noninsulin-dependent) diabetes
Most common type of diabetes
 Obesity and inactivity are risk factors
 Insulin is produced, but there is decreased response to the insulin perhaps
because of a lack or deficiency in insulin receptors.


Consequences:

May lead to blindness, kidney disease, & circulatory disorders like
atherosclerosis, heart disease, and stroke. Lack of circulation may also cause
gangrene. Diabetic coma may also result and there is an increased risk of having
a stillborn child.
7. Reproductive System
Components:
Female: Ovaries, oviduct, uterus, vagina, and
associated structures
Male: Testes, seminal vesicles, prostate, urethra,
penis, and associated structures.
Functions:
 Only
organ system that is not essential for individual
survival.
 Continuation of species.
 Gamete formation (eggs and sperm cells).
Homeostatic Role:
 Maintains
secondary sexual characteristics.
Reproductive System of Humans
Reproductive Functions of Male:
Produces sperm
 Delivers sperm to female reproductive tract

All of these processes are regulated and coordinated by
hormones secreted by:
Hypothalamus
 Pituitary gland (anterior portion)
 Testes (Sing. Testis)

Male Reproductive System
Major Organs of Male Reproductive
System:
 Testes: Paired male gonads.
 Produce
sperm through spermatogenesis, which
produces four sperm cells of equal size.
 Spermatogenesis occurs in a vast system of hollow
tubes called seminiferous tubules.
 Each mature sperm has a head, a midpiece, and a
flagellum.
 Sperm head has an acrosome, which produces
enzymes that help it penetrate the egg.
 Human sperm cannot develop at body temperature.
 Testicles descend from abdominal cavity into scrotum,
a skin covered sac, about two months before birth.
 Undescended testicles (cryptorchidism) may cause
infertility.
Reproductive System of Humans
Major Organs of Male Reproductive System:
 Epididymus:
 Large
coiled tube (23 ft long) that surrounds testes.
 Stores sperm while they develop fertilizing ability and motility
(about 20 days).
 During ejaculation, sperm cells are propelled from
epididymus.

Vas Deferens:
 Long
muscular ducts from scrotum to back of bladder.
 During ejaculation, the sperm pass from epididymus into
these two ducts.
 Vasectomy: Each vas deferens is cut to prevent sperm from
entering urethra.
Reproductive System of Humans
Major Organs of Male Reproductive System:
 Ejaculatory Duct:
 Short

duct after two vas deferens ducts unite.
Urethra:
 Deliver
sperm to the exterior.
 In males, urine and sperm pass through the urethra.
 Females have a separate urethra from the reproductive
system.
Reproductive System of Humans
Major Organs of Male Reproductive System:
Accessory Glands: Produce semen.
 Functions
of semen:
 Activate sperm cells
 Provide nutrients for motility
 Counteract acidity of vagina and male urethra
 Stimulate contractions of female reproductive tract
 Antimicrobial action
 Ejaculation volume 4 to 5 ml.
 One ejaculation has 50-500 million sperm cells
 Sperm cells account for less than 5% of semen volume.
 Secretions from 3 different accessory glands make up the rest
of the volume: Seminal vesicles (2), prostate, and
bulbourethral glands (2).
Major Organs of Male Reproductive System:
Accessory Glands:
A. Seminal vesicles (2): Secrete fluid that
nourishes sperm.
Contribute
about 60% of semen volume.
Thick, clear, alkaline fluid.
Contains:
 Fructose:
Provides energy for sperm motility.
 Prostaglandins: Stimulate smooth muscle
contractions of female and male reproductive tracts.
 Fibrinogen: Forms temporary clot in vagina.
Sperm
cells become highly motile when mixed
with this fluid.
Accessory Glands:
B. Prostate gland: Produces a thin milky secretion.




Largest of semen secreting glands.
Contributes 30% of semen volume.
Produces an antibiotic that may prevent urinary tract infections in men.
Benign (noncancerous) prostate enlargement is common among older men.



50% of men over 40.
Almost all men over 70.
Prostate cancer is the second leading cause of cancer and cancer deaths in
men.




Over 330,000 new cases/year and 40,000 deaths.
Average age at diagnosis: 72
Detected by blood test or digital rectal exam.
Treated surgically or with drugs to reduce prostate size or activity.
Major Organs of Male Reproductive System:
Accesory Glands:
C. Bulbourethral glands (2): Release a
mucous secretion that lubricates penis and
facilitates its entry into vagina.
Pair
of small glands below the prostate.
Contribute 5-10% of semen volume.
Before ejaculation secrete a clear mucus that
neutralizes acid from remaining urine in
urethra.
Bulbourethral fluid also carries some sperm
that is released before ejaculation. One cause
of high failure rate of withdrawal method.
Major Organs of Male Reproductive System:
 Penis: Copulatory organ that delivers
sperm to female body.
 Composed
of three cylinders of erectile tissue.
 During sexual arousal, the penis fills with blood from the
arteries.
 Erection is essential for penetration.
 Impotence is the inability to maintain an erection.


May be caused by alcohol, drugs, illness, and/or emotional problems.
Viagra acts by relaxing smooth muscle of penis blood vessels, allowing
blood to enter erectile tissue.
 Penis


structure:
Shaft: Long cylinder with thick skin.
Glans: Enlarged tip of penis. Thin skin, covered by prepuce or
foreskin.
Reproductive System of Humans
Reproductive Functions of Female:
Produces eggs (ova)
 Receives sperm
 Incubates and nourishes the embryo and fetus
 Gives birth
 Produces milk for young

All of these processes are regulated and coordinated by
hormones secreted by:
Hypothalamus
 Pituitary gland (anterior portion)
 Ovaries

Female Reproductive System
Reproductive System of Humans
Major Organs of Female Reproductive System:
 Ovaries: Produce ova (oogenesis) and sex
hormones.
 Size
and shape of large almonds.
 Located close to lateral walls of pelvic cavity and held
in place by connective tissue.
 Mainly connective tissue containing scattered eggs
(ova) in different stages of development.
 Follicles: A single egg with surrounding cells that
nourish and protect it.


Women are born with all of their follicles (40,000 to 400,000).
Only a fraction of follicles release eggs during a woman’s
reproductive life.
Female Reproductive System:
 Ovulation
& Oogenesis: After puberty, each month one
immature egg (oocyte), is released from ovary.
Each follicle contains a primary oocyte, arrested in prophase I of
meiosis.
 Pituitary hormones FSH (follicle stimulating hormone) and LH
(luteinizing hormone) cause a follicle to enlarge and complete meiosis
I.
 One large cell (secondary oocyte) and a tiny cell (polar body) are
produced.
 LH (luteinizing hormone) causes the secondary oocyte to be released
by the ovary during ovulation.
 Oocyte will not finish meiotic division, until fertilized.
 In the end, one large ovum (egg) and 3 small polar bodies are made
from oogenesis.

Major Organs of Female Reproductive System:
 Oviducts (Fallopian Tubes): Transport the egg from the
ovary to the uterus.
 Peristalsis
of smooth muscle in oviduct and beating of cilia,
help the egg move along.
 Fertilization occurs in the first third of oviduct.
 Scarring of oviducts is a common consequence of sexually
transmitted diseases: chlamydia and gonorrhea.
 Ectopic Pregnancy: Fertilized egg does not reach the uterus.
Usually starts to develop in oviduct.




Usually due to a blocked oviduct.
Occurs in 1% of all pregnancies in the U.S.
Must be surgically removed.
May cause death and severe hemorrhage.
Reproductive System of Humans
Major Organs of Female Reproductive System:
 Uterus: Incubates the embryo/fetus.
 Size
of a fist, in center of pelvic cavity.
 Oviducts open into upper corners of uterus.
 Has thick walls of smooth muscle (myometrium) responsible
for uterine contractions and cramps.
 Endometrium: Inner mucous lining, which thickens each
month in preparation for pregnancy.
 If fertilization does not occur, endometrium breaks down and
is discharged during menstruation.
 If fertilization occurs, the egg implants in the endometrium
which supports its growth until the placenta develops.
Reproductive System of Humans
Major Organs of Female Reproductive
System:

Cervix: Lower portion of the uterus, which projects into
the vagina.
 Pap
smear: Examination of cervical tissue to detect
abnormalities. Recommended yearly.
 Cervical cancer: Most cases caused by a viral infection with
human papillomavirus.
 Women are infected through intercourse with asymptomatic
male.
 Takes about 20 to 30 years to develop.
 Men don’t appear to be affected.
Reproductive System of Humans
Major Organs of Female Reproductive System:
 Vagina: Thin walled, muscular chamber.




Vulva: External structures.






Receives the sperm and penis
Acid pH kills bacteria and sperm cells
Part of birth canal
Clitoris: Equivalent to male penis.
Labia minora: Skin folds that border vaginal opening.
Labia majora: Protect entire genital region.
Hymen: Ring of tissue that forms a border around vaginal entrance. No
known function.
Bartholin’s gland: Secrete lubricating fluid during sexual arousal.
Breasts: Lactation
8. Nervous System
Components: Brain, spinal cord, nerves, sense
organs, and associated structures.
Functions:
 Works
with endocrine system to coordinate body
activities.
 Integrates and processes information from sense
organs.
 Sends signals (instructions) to muscles and glands.
 Responds to internal stimuli.
Homeostatic Role:
 Regulates
system.
most organ activities along with endocrine
Human Nervous System
Functions of Nervous Tissue
1. Sensory Input: Conduction of signals from
sensory organs (eyes, ears, nose, skin, etc.) to
information processing centers (brain and spinal
cord).
2. Integration: Interpretation of sensory signals and
development of a response. Occurs in brain and
spinal cord.
3. Motor Output: Conduction of signals from brain
or spinal cord to effector organs (muscles or
glands). Controls the activity of muscles and
glands, and allows the animal to respond to its
environment.
Nervous System Allows Us to Respond to Our Environment
Cells of Nervous Tissue
1. Neuron: Nerve cell. Structural and functional
unit of nervous tissue.
 Carry
signals from one part of the body to another.
2. Supporting cells: Nourish, protect, and insulate
neurons.
 There
are roughly 50 supporting cells for every neuron.
 In humans, Schwann cells wrap around the axons of
neurons, forming a myelin sheath that is essential for
transmission of nerve impulses.
Neuron Structure
Cell
body : Contains nucleus and most organelles.
Dendrites:
Extensions that convey signals towards
the cell body.
 Short,
numerous, and highly branched
Axon:
Extension that transmits signals away from
the cell body to another neuron or effector cell.
 Usually
 Axon
a long single fiber.
is covered by a myelin sheath made up of many
Schwann cells that are separated by small spaces (Nodes
of Ranvier).
Structure of the Neuron
Neuron Structure
 Myelin
sheath and nodes of Ranvier greatly speed up nerve
impulses, which jump down axon from node to node.
Speed of signal
Myelinated axon
Unmyelinated axon
 Multiple
100 meters/second
5 meters/second
sclerosis: A disease in which a person’s immune
system destroys the myelin sheaths on their neurons.
• Loss of muscle control
• Impaired brain function
• Death
What is a Nerve Impulse?
An electrical signal that depends on the flow
of ions across the neuron plasma
membrane.
 Resting
Potential: A neuron at rest has a net
negative charge (-70 mV, equivalent to 5% of the
voltage in AA battery).
The net negative charge is due to different ion
concentrations across the neuron membrane.
What is a Nerve Impulse?
An electrical signal that depends on the flow of ions across
the neuron plasma membrane.
 Action
Potential: When a neuron is stimulated above a
certain threshold, this causes:
1. Depolarization: An influx of positive ions (Na+) into the
cell, caused by the opening of sodium channels.
The inside of the cell becomes positively charged for a
brief moment (1-2 milliseconds).
2. Repolarization: After a few milliseconds, the neuron
allows other positive ions (K+) to leave the cell so the
inside of the cell becomes negatively charged once
again.
Resting Potential is Caused by Differences in Ion
Concentrations Across Neuron Membrane
Action Potential Requires Stimulus
Above a Certain Threshold
Nerve Impulses are Caused by Action
Potentials
Neurons Communicate at Synapses
Synapse: Junction between two neurons or a
neuron and an effector cell (muscle or gland).
There are two types of synapses:
1. Electrical Synapse:
Found in heart and digestive tract of human body.
 Action potentials pass directly from one neuron to another.

2. Chemical Synapse:
Found in CNS, muscles, and most other organs.
 Require neurotransmitters: Chemicals that convey
messages from one neuron to another.
 Transmitting neuron releases neurotransmitters which cross
synapse and cause an action potential in the receiving
neuron.

Synapse


Functional connection between a neuron and
another cell.
Different types of synapses involve:

Axonodendritic:


Axosomatic:


Axon of one neuron and cell body of another neuron.
Axoaxonic:


Axon of one neuron and dendrite of another neuron.
Axon of 1 neuron and axon of another neuron.
Transmission in one direction only.
Chemical Synapses Use Neurotransmitters
Diseases of the Nervous System
I. Alzheimer’s Disease





Most common form of dementia in U.S.
Unknown cause, probably both genetic and environmental factors are
important.
No effective treatment
Certain diagnosis is usually only possible through discovery of typical
brain lesions during autopsy.
Usually affects elderly: Over 4 million cases in U.S.



10% of those over 65
Almost half of those over 85
Symptoms progress over time. Three stages:

Mild Stage: Forgetfulness, minor disorientation, mild personality changes,
depression, difficulty in finding right words during conversation, and
performing arithmetic calculations (e.g.: balancing checkbook).
Diseases of the Nervous System
I. Alzheimer’s Disease (Continued)

Stages of Alzheimer’s Disease:

Moderate Stage: Noticeable memory loss, difficulty performing
everyday tasks (bathing, dressing, cooking, driving, operating
appliances), may wander off, confuse day and night, fails to recognize
acquaintances and distant relatives.

Severe Stage: Very limited speech (less than 12 words), eventually
becomes mute and uncomprehending, loses all self-care ability, can’t
recognize closest relatives, friends, or caregivers, becomes
incontinent, progressively loses ability to walk, stand, sit up, smile,
and hold head up. Many patients die from complications like
pneumonia.
Brain Atrophy in Alzheimer’s Disease
Definite diagnosis of Alzheimer’s usually requires post-mortem brain examination.
Notice pronounced atrophy with wide sulci (grooves) in frontal and parietal regions.
Source: www-medlib.med.utah.edu/WebPath/CNSHTML
9. Muscular System
Components: Skeletal muscles.
Functions:
Skeletal muscle contraction allows for voluntary
movement:
 Movement
and locomotion.
 Mechanical work: Lifting, pulling, pushing objects.
 Communication: Body language and facial expression.
Homeostatic Role:
 Allows
animals to respond to and control their
environment.
Muscular System: Skeletal Muscle Allows
Voluntary Movement
10. Skeletal System
Components: Bones, ligaments, and cartilage.
Functions:
 Along


with muscular system:
Movement and locomotion.
Mechanical work: Lifting, pulling, pushing objects.
 Body
support.
 Protection of delicate internal organs (brain, heart,
lungs, etc.)
 Calcium storage
Homeostatic Role:
 Helps
maintain constant blood calcium levels.
Skeletal System: Protection, Movement, & Support
11. Integumentary System
Components: Hair, skin, and nails.
Functions:
 Protects the body from:
 Infection:
Barrier to microbes.
 Mechanical injury
 Excessive heat or cold: Thermoregulation
 Water loss

Communication:
 Receives
stimuli from environment
 Gives out subtle signals (blushing, etc.).
Homeostatic Role:
 Helps
maintain constant body temperature.
Integumentary System: Skin, Nails, & Hair
Organ systems must be coordinated for
animal to survive
 Organ
systems interact with one another in
order to maintain fairly stable conditions
(homeostasis) that are required for life.
 Example: Interactions between:
• Respiratory
• Circulatory
• Digestive
Relationships Between Several Major Organ Systems