15. When the amount of oxygen carried in blood is reduced, cells in the _____ increase the production of the protein hormone ________.

a. kidney, erythropoietin

b. red bone marrow, calcitonin

c. liver, ferritin

d. kidney, calcitonin

e. red bone marrow, erythropoietin

16. During periods of increased sympathetic activity, drugs that block the norepinephrine receptor on arteriolar smooth muscle (α1 receptors) would be expected to ______________ blood flow by _____________.

a. increase, decreasing vascular resistance

b. decrease, decreasing vascular resistance

c. decrease, increasing vascular resistance

d. increase, increasing vascular resistance 

17. Long term (months to years) increases in the pressure required to open the pulmonary valve would be expected to increase the thickness of the myocardium in the:

a. right atrium.

b. right ventricle.

c. left atrium.

d. left ventricle.

e. pulmonary artery.

18.) Oxygen mostly diffuses from blood into contractile cardiomyocytes across the endothelium of:

a. the endocardium.

b. arteries.

c. arterioles.

d. capillaries.

e. veins.

19. During the production of lymph ____________ generates a ___________ force to return fluid to the

capillary.

a. protein in plasma, osmotic

b. protein in plasma, hydrostatic

c. the heart, hydrostatic

d. the heart, osmotic

e. a and c are correct