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The Circulatory SystemChapter 37
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Circulatory System
OBJECTIVES:• Understand the anatomy and
functions of the circulatory system
• Know how the circulatory system maintains homeostasis
• Know several diseases of the circulatory system
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Circulatory System
I. OverviewA. Functions of the Circulatory
System (CS)1. Internal transport system2. Delivers O2 and nutrients to cells
3. Removes CO2 and metabolic wastes from cells
4. Interacts with digestive, respiratory and excretory systems to maintain homeostasis
Circulatory System
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General Animal Structure-The circulatory system connects all the systems!
Why do animals need circulatory systems!
O2
CHO
CHO
aa
aa
CH
CO2
NH3aa
O2
CH
aa
CO2
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2
NH3
NH3 NH3
NH3
NH3
NH3
NH3NH3
O2
aa
CH
aa
CHO
O2
• Diffusion is not adequate for moving material across more than 1-cell barrier
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Circulatory System
I. Overview (cont)B. Two Types of circulatory systems
1. Open CSa. Found in smaller and simpler
organisms (e.g. arthropods and mollusks)
b. Blood (Hemolymph) is pumped into open spaces called sinuses.
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Circulatory System
B. Two Types of circulatory systems cont.2. Closed CS
a. Found in larger and more complex organisms (e.g. earthworms and vertebrates)
b. Blood stays in vessels and is pumped in a loop under pressure.
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Circulatory System
I. Overview (cont) Anatomy of CSC. The human circulatory system is
comprised three components: the heart, blood vessels and blood
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Circulatory System
II. The HeartA. Function - Pump blood throughout
the bodyB. Structure
1. The heart is surrounded by a thin protective sac called the pericardium.
2. The majority of the heart is muscle called the myocardium.
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The Circulatory SystemC. Blood Flow through the heart and body (Know
Fig. 37-2, & 37-3 for test!! pg. 944 & 945)1. Blood returns from the upper and lower
body through the superior and inferior vena cavas.
2. The vena cavas empty into the right atrium.
Superior Vena Cava
Inferior Vena Cava
Right Atrium
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The Circulatory System
3. The blood now passes through the tricuspid valve into the right ventricle.
Tricuspid Valve
Right Ventricle
Why do we have valves?
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The Circulatory System
4. Next blood is pumped past the pulmonary semilunar valve into the pulmonary artery.
Pulmonary Semilunar
Valve
Pulmonary Artery
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The Circulatory System
5. Blood is pumped from the left and right branches of the pulmonary artery to the left and right lobes of the lungs.
6. In the lungs, what happens?
Carbon dioxide is release from the blood stream and oxygen is absorbed.
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The Circulatory System
7. Blood returns from the lungs to the heart via the pulmonary veins.
8. The pulmonary veins empty into the left atrium.
Pulmonary Veins
Pulmonary Veins
Left Atrium
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The Circulatory System
9. Blood is pumped through the bicuspid (mitrial) valve into the left ventricle.
Bicuspid (mitrial)
Valve
Left Ventricle
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The Circulatory System
10. Blood is pumped from the left ventricle through the aortic semilunar valve into the Aorta.
Aortic Semilunar
Valve
Aorta
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The Circulatory System
11. The mixing of oxygen-poor blood with oxygen-rich blood is prevented by a wall called the septum.
Septum
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The Heart
Circulation of Blood through the Body
Capillaries of head and arms
Superior vena cava Aorta
Pulmonary veinCapillaries of
right lungs
Inferior vena cava
Capillaries of abdominal organs and legs
Capillaries of left lung
Pulmonary artery
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Circulatory System
D. Factors that Affect Heart Rate1. Blood Pressure - increase in BP will cause
an increase in HR2. Increase in Carbon Dioxide in blood will
cause an increase in HR 3. Gender - females have higher HR than
males.4. Age - the older you get the lower your HR 5. Temperature - as body temperature
increase so does HR
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Circulatory System
III. Blood Vessels (3 Main Types)A. Arteries
1. Thick walled, muscular, and elastic2. Carry blood AWAY from the heart to
tissues and organs Why are arteries thick-walled and muscular? Do arteries always carry oxygenated blood?
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Circulatory System
B. Capillaries
1. Walls are very thin and porous: one-cell thick and very narrow (WHY?)
2. Exchange of materials (Which materials?)
Exchange across capillary walls
Arteriole
Bloodflow
Venule
Lymphaticcapillary
Interstitialfluid
Fluid & solutes flows out of capillaries to tissues due to blood pressure• “bulk flow”
Interstitial fluid flows back into capillaries due to osmosis plasma proteins osmotic
pressure in capillary
BP > OP BP < OP
15% fluid returns via lymph
85% fluid returns to capillaries
Capillary
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Circulatory SystemC. Veins
1. Thin-walled and muscular2. Carries blood TOWARDS the heart3. Many are located near and between skeletal
muscles (WHY?)4. Large veins contain valves (WHY?)
What happens if we sit or stand too long? Do veins always carry deoxygenated blood?
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Veins & their valves
Valve open
Valve closed
Valves closed
Atherosclerosis
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Circulatory SystemIV. Blood
A. Human body contains 4-6 liters B. Composed of 45% cells and 55% plasmaC. Blood Plasma
1. 90% water2. 10% is made of:
a. Dissolved gases (Which three?)b. Saltsc. Enzymes and other proteinsd. nutrients, enzymese. Liquid wastesf. Hormones
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Circulatory System
D. Functions of Blood1. Regulate body temperature2. Transport nutrients3. Fight infection
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• Blood Composition
Whole Blood Sample
Sample Placed in Centrifuge
Plasma
Platelets
White blood cells
Red blood cell
Blood Sample That Has Been Centrifuged
Blood Plasma
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Circulatory System
D. Types of Blood Cells (3 Types)
1. Red Blood Cells:a. Transport oxygen
using special iron-containing protein called hemoglobin that binds oxygen
b. Disk-shapedc. Produced from cells
in red bone marrowd. Have no nucleus and
die after ~100 days
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Circulatory System
2. White Blood Cells (Leucocytes): Protect the body against infection (the immune response).
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Circulatory System3. Platelets (Thrombocytes):
a. Stimulates the formation of blood clots.
b. Platelets come into contact with a damaged blood vessel.
c. The platelets rupture releasing clotting factors.
d. The platelets factors reacts with factors in the blood forming a clot.
e. This process occurs with in minutes.
f. Platelets form in the red bone marrow, lungs, & spleen.
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Circulatory System
• An Activated and inactivated blood platelet.
• The Oval disc is the inactivated platelet
• The other (green) is an activated platelet
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The Circulatory System
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V. Disorders of the blood
A. Anemia (a reduction in bloods ability to carry oxygen)1. Cause by: lack of iron, reduce RBC
formation, excessive bleeding or it can be genetic (Thalassemia).
2. Symptoms: lack of energy3. Treatment: dietary adjustments or
drugs
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V. Disorders of the blood
B. Leukemia1. Caused by an uncontrollable
production of immature leukocytes.2. Symptoms: In ability to fight off
infection3. Treatment: Bone marrow transplants,
radiation and chemotherapy
C. Hemophila and Sickle-Cell Anemia
1. Look back at your notes.
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VI. Disorders of the blood vessels
A. Varicose Veins
1. Cause - valves in the veins fail and blood over stretches the veins
2. Symptoms – Large protruding veins, painful
3. Treatment – Surgery or injections to collapse smaller ones.
4. Prevention – Exercise, don’t cross legs over knees.
*** Hemorrhoids are varicose veins in the rectum.
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VI. Disorders of the blood vessels
B. Aneurysm
1. Hereditary caused by a weakened artery wall.
2. Symptoms – none!
3. Treatment – immediate surgery
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VII. Cardiovascular Disease
A. Kills over a million Americans a year!!
B. Most common form is Coronary Heart Disease.
1. Cause
a. Slow buildup of fatty plaque (atherosclerosis) along the walls of the coronary arteries.
b. Reduced blood flow to hart leads to heart attack.
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VII. Cardiovascular Disease
2. Diagnosis - Outward symptoms of a heart attack:
Pain in the center of the chest lasting more than a few minutes.
Pain will spread to the shoulders, neck, or arms.
Chest discomfort with lightheadedness, fainting
Nausea and a cold sweatShortness of breatheDenial!!
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b. Lab Tests1. Exercise EKG2. Angiogram
a.A small tube is inserted into an artery of pelvis and worked into the aorta.
b.Dye is injected into the artery.c.A fluoroscope will show where the
dye goes.d.Blocked arteries don’t show up.
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3. Treatmenta. Coronary bypass surgery
1. Remove a vein from the leg2. Graft the vein to the aorta and an
unblocked portion of the artery.
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C. Risk factors associated with Heart Disease (Check your parents!)
1. Age
2. Sex
3. Genetics
4. Diets
5. High Blood Pressure
6. Smoking
7. Stress Alcohol
8. Obesity
9. Inactivity
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D. Designing a Good Aerobic Exercise Program1. Work at the correct intensity as measured by heart
rate
athlete 80-90% of the max. HRnormal 70-80% of the max. HRolder 60-70% of the max. HR
(Maximum HR= 220 — age)
*** e.g. a normal person 40 years of age(220-40) x 70%180 x 0.7 =126.0 beats/min.
2. Work for at least 20 minutes or longer 3. Work at least 3 to 4 times a week4. You can do any form of exercise that allows you to meet
the first three requirements.