Circulatory System
3 Primary Components
1. Heart
2. Blood
3. Vessels
-60,000 miles of
vessels in our body
-100,000 beats/day
-6 quarts of blood in
our body
Cardiovascular System
FX: allows for blood
movement throughout
body so that:
1. oxygen/nutrients can
get to body cells
2. waste can be
removed from cells
Heart: hollow, cone shaped, muscular
pump
-located in the thoracic cavity,
behind the sternum
-2nd rib to the 5th inter costal space
-about as large as your fist
4 Layers:
1. Pericardium: connective tissue
around the heart
2. Epicardium: upper layer of
heart
3. Myocardium: middle layer that
contains cardiac muscle and
vessels
4. Endocardium: inner layer that
lines the interior of the heart
Heart Chambers
Evolution
1. open circulatory
systems (arthropods)
2. closed circulatory
systems (vertebrates)
ex. Fish,
amphibian, reptile, and
mammal hearts
Four Chambered Heart
-Two Atria: left and right –
receive blood from veins –
thin wall
-Two Ventricles: left and right
– send blood to the interior
-Septum: separates right and
left halves
-Arteries: send oxygenated
blood from the heart
(except pulmonary artery)
-Veins: bring deoxygenated
blood back to the heart
(except pulmonary vein)
Pulmonary Circulation
Right Ventricle
Pulmonary
Artery
Left Ventricle
Lungs
Left Atrium
Pulmonary Vein
General Heart Anatomy
1. Aorta- large muscular
vessel that carries
oxygenated blood away
2. Vena Cava- large vein
that carries
deoxygenated blood to
heart (superior/inferior)
3. Atrium-thin walled
chamber
4. Ventricle-thick muscle
walled chamber
Valves: mechanical devices that
control fluid flow by opening/closing
Cuspid Valves (point)
(Atrioventricluar)
1. Tricuspid Valve
2. Bicuspid Valve
P. 665/666
Semilunar Valves
1. Pulmonary Semilunar
2. Aortic Semilunar
Blood Pathway Through the Heart
1. Right atrium receives deoxygenated blood from
the body tissue via the inferior/superior vena
cava
2. Blood in right atrium passes through the
atrioventricular oriface. Tricuspid valves open
into right ventricle when right atrium contracts
3. Right AV oriface has a tricuspid valve which
when closed, prevents back flow of blood into R
atrium
Blood Pathway Through the Heart
4. When the ventricle contracts, blood is forced
into the pulmonary trunk. The pulmonary trunk
leads to the pulmonary arteries which take
deoxygenated blood to the lungs for oxygen.
5. Oxygenated blood returns to the heart via
pulmonary veins to the left atrium
6. Atrium wall contracts and moves the blood past
the bicuspid valves to the left ventricle
7. Left ventricle contracts (bicuspid close) and
blood passes into the aorta and systemic
ciculation
Actions of the Heart
Heart chambers don’t
function independently
-atrial walls contract
-while the ventricle walls
relax
Heart Sounds
-two distinguishable sounds
“lub-dub”
-associated with closing of
valves
- “lub” – AV valves close:
onset of systole (ventricular
contraction)
- “dub” – semilunar valves
snap shut: diastole
(ventricular relaxation)
- Heart murmur: a
malfunctioning valve –
blood flows silently unless
obstructed
Cardiac Cycle
1. Medulla oblongata: sends
impulse to the sino-atrial
node (SA node) on the
right atrium (atrial
contraction)
2. SA sends depolarization
signal to atrio-ventricular
node (AV node). 0.6 sec
delay allows for atria to
relax
3. AV node sends impulse to
Bundle of His  signal to
branches which causes
ventricular contraction
Medullaoblongata
Vagus nerve
SA node
AV node
Bundle of HIS
Bundle Branches
Electro Cardiogram (ECG)
- P-Wave: depolarizaiton
of the atria before atrial
contraction
- QRS Complex: ventricular
depolarization before
ventricular contraction
- T-Wave: ventricular
repolarization
- PR interval: atrial
contraction
- QT interval: ventricular
contraction
Blood Vessels
Arteries
Arteriolescapillaries
venulesveins
-exchange nutrients, gases,
waste occurs in the
capillaries
-Veins/venules drain blood
from capillaries and
return it to right atria
-arteries carry blood away
from heart
Vasoconstriction vs. Vasodilation
- Vasoconstriction:
decrease in blood vessel
diameter
(smooth muscle
contracts; sympathetic
nerve fiber)
- Vasodilation: increase
in blood vessel
diameter
(smooth muscle relaxes)
Heart Disease
1. Myocardial infarction (heart attack)
- 50% of U.S. deaths
- Sedentary lifestyle
(outdoor indoor)
- Tissues that die due to
obstructions in blood
vessels (pumps blood to
itself)
Heart Attack Symptoms
- Pressure in chest,
tightening behind
sternum
- Radiating pain to nech,
arms, shoulders, elbow,
and back
- Nausea and difficulty
breathing
- Some are silent
Risk Factors
1. High cholesterol
2. Sugar diabetes (Type II)
3. Hypertension (high
blood pressure)
4. Stress
5. Smoking
6. Family history
7. Sedentary lifestyle
8. Male
Preventative Maintenence
1.
2.
3.
4.
5.
6.
Know family history
Watch your diet
Exercise
Periodic checkups
Don’t smoke
Reduce stress
(decrease your load;
pray/meditate)
2. Thrombus: a blood clot abnormally
forms in a vessel
- Coronary thrombus:
heart (MI)
- Cerebral thrombus:
cerebrum (stroke)
- Pulmonary thrombus
3. Embolus: a blood clot that breaks
away and is carried by blood flow
- anticoagulants:
chemicals used to thin
blood (aspirin, heparin,
wharfarin)
4. Atherosclerosis: build up of fat
deposits in arteries
Causes:
-excessive saturated fats
-high cholesterol
Cholesterol:
-High density lipoprotein
(HDL) = bad
- Low density lipoprotein
(LDL) = good
5. Ischemia: blood oxygen deficiency
in myocardial tissue
Heart Procedures
1. Open heart surgery
2. By-pass surgery of coronary arteries
3. Cardio myoplasty
4. Angioplasty Procedures
Blood: connective tissue with cells in
a fluid matrix
Centrifuged Blood:
-45% cells (hematocrit)
-55% fluid (plasma/yellow)
-average adult has 5 liters
-8% of our body weight
-mean T = 38 C (100.4 F)
Functions
1. Transport:
- Oxygen and carbon
dioxide
- Waste to liver and
kidneys
- Carries hormones to
target cells
- Carries heat to the skin
- Nutrients from digestive
system
2. Protection:
a) Role in inflammation
(diseases ending in “itis”)
b) Immunity:
-leukocytes destroy
viruses, bacteria, and
protist
-antibodies neutralize
pathogens
c) Clotting
-platelets initiative
clotting
3. Regulation:
-water to and from tissues
-buffers acids and bases
-electrolyte and salt
balance
Blood Cell Types
- Made in bone marrow
1. RBC – erythrocytes
2. WBC –leukocytes
3. Platelets – cell
fragments
Red Blood Cells - Erythrocytes
FX: pick up oxygen in
lungs and carry it to
tissue/pick up CO2 and
unload it in lungs
- Contains hemoglobin
- Biconcave disc that lack
nuclei
- RBC counts determine
disease diagnosis
RBC Life Cycle
- Circulates 120 days
- Removed by
macrophages in liver
and spleen
- New RBC controlled by
erthropoietin hormone
and proper diet
Associated conditions:
1. Anemia – deficiency in
RBCs
2. Hypoxia – inadequate
oxygen in tissues
White Blood Cells - Leukocytes
FX: immune system –
phagocytosis –
-can move out of vessels
and leave circulation
Five Types of WBCs
1. Monocytes:
(Agranulocyte)
-activate immune system
-contain lysosomes
-phagocytize foreign
particles
Five Types of WBCs
2. Lymphocytes:
(Agranulocyte)
-specific immunity
function
-destroy cancer cells,
virus, and foreign cells
-attacked by HIV
Five Types of WBCs
3. Basophil:
(Granulocyte)
Two types:
-contains heparin –
inhibits blood clotting
-contains histamine –
increases blood flow
to injured tissue
Five Types of WBCs
4. Eosinophils:
(Granulocyte)
-control inflammation
from blood tissue
damage
-control allergic reactions
Five Types of WBCs
5. Neutrophil:
(Granulocyte)
-phagocytize pathogens
-multi-lobed nucleus
WBC Disorders
1. Leukemia
Acute – spreads rapidly
Chronic – spreads slowly
-death is caused by
internal bleeding and
infection
-vinblastine/vincristine
used in treatment
WBC Disorders
2. Mononucleosis:
- Viral disease (EpstienBarr)
- Young adults
- Excessive number of
monocytes
- Tired, achy, fever, sore
throat
- Rest for weeks – no
cure
Blood Types and Transfusions
Early problem of transfusion:
Agglutination: clumping of red blood cells causing
death
Caused by two proteins:
1. Aggluntinogens: in red blood cells
2. Agglutinins: found in plasma
Blood type determines the agglutinogens which
cause transfusion reactions
Blood Types
- Each blood type has an “anti” factor in blood
plasma – agglutinins
Two Types of Agglutinogens: A and B
Two Types of Agglutinins: Anti A and Anti B
Type A bonds with Anti A = agglutination=death
Type B bonds with Anti B= aggluntination=death
Type AB has no agglutinin
Type O has both agglutinins
Transfusion:
Blood Type
Preferred Donor
Possible Emergency
A
A
O
B
B
O
AB
AB
A,B,O
O
O
none
Rh Factor
- Another blood type
- Discovered in Rhesus
monkeys
- 85% of Americans are
Rh+ (Rh agglutinogens)
- Rh- has no
agglutinogens
- Rh- can receive Rh+
blood not vice versa
Rh factor and Pregnancy
- Maternal and fetal
blood mix
- If Rh- mother recieves
Rh+ blood agglutination
will occur (or vice versa)
- 1st pregnancy typically
unaffected
- Mother is sensitized for
second
- Treated wit ROGAM