Cardiovascular System

Question 1

Outline the pathway of blood flow through the heart.

Answer 1

In pulmonary (lung) circulation: Blood moves from the right ventricle of the heart to the lungs and back to the left atrium
In systemic (rest of the body) circulation: Blood moves fro the left ventricle to the body, back to the right atrium

Question 2

Compare arteries, veins, and capillaries.

Answer 2

Arteries, veins, and capillaries all consist of endothelium, but they each have different functions:
Arteries carry blood AWAY from the heart,
Veins carry blood TO the heart, and
Capillaries exchange materials between tissues

Question 3

State the function of capillaries.

Answer 3

Capillaries, which are just one epithelial cell thick, are responsible for exchanging oxygen and carbon dioxide through their thin walls.

Question 4

Compare pulmonary and systemic circulation.

Answer 4

Pulmonary circulation exchanges CO2 for O2 in the lungs.

Systemic exchanges O2 for CO2 in the body.

Question 5

List the components of blood.

Answer 5

55% plasma (the liquid portion of the blood)

45% cell fragments

Question 6

State the function of each component of the blood.

Answer 6

Red blood cells (erythrocytes): carry oxygen to cells
White blood cells (leukocytes): supplement the immune system by marking and destroying certain harmful cells that have invaded the body
Platelets (fragments of WBCs): help blood to clot, which prevents us from bleeding out each time we incur a small injury.

Question 7

Explain how blood pressure and blood volume impact low blood flow in the body.

Answer 7

Higher blood pressure causes vessels to contract, slowing blood flow.
Similarly, as blood volume decreases, blood flow slows because the heart does not have enough to pump.