Transcript Circulatory System

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
Circulatory System
I.
Overview
A. Functions of the Circulatory System (CS)
1. Internal transport system
2. 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
I.
Overview (cont)
B.
Two Types of circulatory systems
1. Open CS
a. Found in smaller and simpler organisms
(e.g. arthropods and mollusks)
b. Blood is pumped into open spaces called
sinuses.
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.
Circulatory System
I.
Overview (cont)
C. The human circulatory system is comprised of three
components: the heart, blood vessels and blood
II. The Heart
A.
Function
1. Pump blood throughout the body
B. 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
Circulatory System
C.
Factors that Affect Heart Rate
1. Blood Pressure - increase in BP will cause
an increase in HR
2.
3.
4.
5.
Increase in Carbon Dioxide in blood will cause an
increase in HR
Gender - females have higher HR than males
Age - the older you get the lower your HR
Temperature - as body temperature increases so
does HR
Circulatory System
Circulatory System
III.
Blood Vessels (3 Main Types)
A. Arteries
1. Thick walled and muscular
2. Carry blood AWAY from the heart to tissues
and organs
 Why are arteries thick-walled and muscular?
 Do arteries always carry oxygenated blood?
Circulatory System
B.
Capillaries
1. Walls are very thin and porous: one-cell thick
and very narrow (WHY?)
2. Exchange of materials (Which materials?)
Circulatory System
C.
Veins
1. Thin-walled and muscular
2. Carries blood TOWARDS the heart
3. 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?
Circulatory System
IV.
Blood
A. Human body contains 4-6 liters
B. Composed of 45% cells and 55% plasma
C. Blood Plasma
1. 90% water
2. 10% is made of:
a. Dissolved gasses (Which two?)
b. Salts
c. Enzymes and other proteins
d. nutrients
e. Liquid wastes
f. Hormones
Circulatory System
D. Types of Blood Cells (3 Types)
1. Red Blood Cells (Erythrocytes):
a. Transport oxygen using
special iron-containing protein
called hemoglobin that binds
oxygen
b. Disk-shaped
c. Produced from cells in red
bone marrow
d. Have no nucleus and die
after ~100 days
Circulatory System
2. White Blood Cells (Leucocytes)
a.
b.
Protect the body against infection
Use phagocytosis to engulf pathogens
Circulatory System
3. Platelets (Thrombocytes):
a. Stimulate the formation of blood clots
b. Platelets come into contact with a damaged
blood vessel.
c. The platelets rupture releasing clotting factors
d. The platelet factors reacts with factors in the plasma
forming a clot.
e. This process occurs with in minutes.
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 energy
3. Treatment: dietary adjustments or drugs
B. Leukemia
1. Caused by an uncontrollable production of immature
leukocytes.
2. Symptoms: Inability to fight off infection
3. Treatment: Bone marrow transplants, radiation and
chemotherapy
C. Hemophila and Sickle-Cell Anemia
1. Look back at your genetics notes.
VI. Disorders of the Blood Vessels
A.
B.
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.
Aneurysm
1. Hereditary, artery wall is weakened.
2. Symptoms - none!
3. Treatment - immediate surgery
VII.
Cardiovascular Disease
A. Kills over 1 million Americans a year!
B. Most common form is Coronary Heart Disease
1. Cause
a. Slow build up of fatty plaque (atherosclerosis)
along the walls of the coronary arteries
b. Reduced blood flow to heart leads to a heart attack
2. Diagnosis
a. Outward symptoms of a heart attack
• pain in chest and left arm
• cyanosis of lips
• nausea and a cold sweat
• dizziness
• shortness of breath
• denial!!!
VII.
Cardiovascular Disease
b. Lab Tests
1. Exercise EKG
2. 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
3. Treatment
a. Coronary bypass surgery
1. Remove a vein from the leg
2. Graft the vein to the aorta and an unblocked portion of
the artery.
3.
Treatment (cont.)
b. Angioplasty
1. A small tube with a balloon at the end is inserted
into an artery in the leg.
2. The tube is manipulated into the block artery of
the heart.
3. The balloon is inflated.
4. The fatty plaque is smashed up against the
artery wall
5. Sometimes a stint is placed in the artery to keep
the artery open
C. Stroke (The interruption of blood flow to the brain)
1. Causes
a. Blood clot
b. Atherosclerosis
c. An aneurysm
D. Risk Factors associated with Heart
Disease (Check your parents!)
1. age
2. gender
3. genetics
4. diets high in fat (hyperlipidemia)
5. high blood pressure
6. smoking
7. stress
8. alcohol
9. obesity
10. inactivity
E. Designing A Good Aerobic Exercise Program
1. Work at the correct intensity as measured by heart rate
athlete
80-90% of the max. HR
normal
70-80% of the max. HR
older
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 week
4. You can do any form of exercise that allows you to meet the first
three requirements.