Download Study Guide: Circulatory System

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Study Guide: Circulatory System
Directions: Read pages 400-411 in Prentice Hall Science Explorer. Answer the following questions.
1. What is the function of the circulatory or cardiovascular system?
It carries needed substances to cells and carries waste products away from cells. Also, blood
contains cells that fight disease.
2. Describe the structure of the heart.
It consists of four chambers: the right and left atriums and the right and left ventricles.
3. What is the function of the heart?
The heart produces muscular contractions that push blood throughout your body.
4. What is the difference between a ventricle and an atrium?
Atriums form the upper chambers and ventricles form the lower chambers; the left ventricle has
the thickest walls because it pumps blood out to the body.
5. What is the function of the valves in the heart?
The valves open to allow blood to flow in one direction through the heart. This prevents the
blood from flowing backwards.
6. The heart is a two-phase pump. Describe the action of the heart.
The right side receives blood from the body and pumps it to the lungs.
The left side of the heart receives blood from the lungs and pumps it to the rest of the body.
7. What causes the “lub-dup” sound in the heart?
The closing of valves in the heart as the ventricles contract and relax; these are the two phases of
the heart.
8. What is the “pacemaker” in the heart? What is its function?
The pacemaker is a group of cells located in the right atrium that sends out signals that make the
heart muscle contract and that regulates heart rate. It receives internal stimuli about the body’s
oxygen needs and responds to that need.
9. What are the three types of blood vessels? Give the function of each type.
a.
Arteries: carry blood away from the heart to other parts of the body.
b. Capillaries: nutrients, oxygen, and waste move across the thin walls and into the body
cells.
c.
Veins: carry blood back to the heart.
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10. The blood travels through the body in two loops. In the first loop, or pulmonary system, the blood travels
from the heart to the lungs and back. What happens to the blood in the lungs?
The blood releases CO2 and picks up oxygen.
11. In the second loop, or systemic system, the blood travels from the heart throughout the body and returns to
the heart. What happens to the blood in the capillaries in the body?
The capillaries are in close contact with body cells. Oxygen is removed from the blood and into
the body cells. Carbon dioxide is removed from the body cells and into the blood.
12. Briefly describe the structure of the following:
a. Arteries- Thick walls that consist of three layers of muscle and tissue that enable it to
withstand the pressure of the blood pumping throughout the body.
b. Capillaries- Very small and thin structures that allow materials (wastes and nutrients) to
pass through between the blood and the body cells.
c. Veins-Blood vessels with thin walls that consist of three layers of muscle and tissue
13. What causes a “pulse” in your artery?
A pulse is caused when an artery expands then relaxes as blood surges through the artery.
14. Define blood pressure.
Blood pressure is the force at which blood moves through your arteries.
Directions: Using page 403 in your book. Label and describe the parts of the heart.
Major vein from the
upper body to the heart
Pacemaker:
Regulates the
beating of the heart.
Right Atrium: Receives
blood from the body that’s
low in oxygen and high CO2
Right Ventricle: When it
contracts, it pumps oxygen
poor blood to the lungs.
Major vein from the lower
body to the heart
Aorta: the largest blood vessel
in the body that carries blood
from the left ventricle to the
body
Artery from the heart to lungs
Left Atrium: Oxygen rich blood moves
from the lungs into left atrium
Left Ventricle: Pumps oxygen rich blood
to all parts of the body
Septum: Thick muscular layer that
separates left side of heart from right
side. Prevents mixing of oxygen-rich blood
and oxygen-poor blood.