Question

1. Where are the heart valves located and describe the purpose of each valve. (10 points – location, function, citation, grammar/spelling)

2. Why is there more muscle tissue around the left ventricle than the other three chambers?(3 points – answer, citation, grammar/spelling)

3. Describe pulmonary circulation versus systemic circulation. (4 points – answer, citation, grammar/spelling)

4. In what vessel does blood gas exchange occur?(3 points – answer, citation, grammar/spelling)

5. What is the purpose of blood gas exchange? (3 points – answer, citation, grammar/spelling)

6. Myocardial infarction: (3 points – answers, citation, grammar/spelling)
   1. Explain what causes a heart attack.
   2. Which vessel(s) are involved in a heart attack?
   3. What are the signs and symptoms of a heart attack?

7. Stroke: (5 points – answers, citation, grammar/spelling)
   1. What are the two types?
   2. Which vessel(s) are involved in a stroke?
   3. What are the signs and symptoms of a stroke?
   4. If a patient survives, list or describe some of the permeant physiological damages that a stroke survivor may have.

8. Explain the surgical procedure of angioplasty? (3 points – answer, citation, grammar/spelling)

Answer 1

Ans) The heart consists of four chambers, two atria (upper chambers) and two ventricles (lower chambers). There is a valve through which blood passes before leaving each chamber of the heart. The valves prevent the backward flow of blood. These valves are actual flaps that are located on each end of the two ventricles (lower chambers of the heart). They act as one-way inlets of blood on one side of a ventricle and one-way outlets of blood on the other side of a ventricle. Each valve actually has three flaps, except the mitral valve, which has two flaps. The four heart valves include the following:

tricuspid valve: located between the right atrium and the right ventricle
pulmonary valve: located between the right ventricle and the pulmonary artery
mitral valve: located between the left atrium and the left ventricle
aortic valve: located between the left ventricle and the aorta

Heart valves function:
As the heart muscle contracts and relaxes, the valves open and shut, letting blood flow into the ventricles and atria at alternate times. The following is a step-by-step illustration of how the valves function normally in the left ventricle:

After the left ventricle contracts, the aortic valve closes and the mitral valve opens, to allow blood to flow from the left atrium into the left ventricle.
As the left atrium contracts, more blood flows into the left ventricle.
When the left ventricle contracts again, the mitral valve closes and the aortic valve opens, so blood flows into the aorta.

- The ventricles of the heart have thicker muscular walls than the atria. This is because blood is pumped out of the heart at greater pressure from these chambers compared to the atria. The left ventricle also has a thicker muscular wall than the right ventricle, as seen in the adjacent image.

- Pulmonary circulation moves blood between the heart and the lungs. ... The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body. It sends oxygenated blood out to cells and returns deoxygenated blood to the heart.

- Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.