31) Which of the following is(are) the only factor(s) that can be adjusted by the nervous or endocrine system to regulate blood flow?

A) vascular resistance

B) turbulence

C) viscosity

D) vascular resistance and viscosity

E) turbulence and viscosity

32) The third and fourth heart sounds are generated by

A) vascular resistance.

B) opening valves.

C) closing valves.

D) viscosity.

E) turbulence.

33) In the respiratory pump process to increase venous return, inhalation results in a(n) ________ in the thoracic cavity, which causes the inferior vena cava and right atrium to expand and fill with blood.

A) increase in pressure

B) decrease in capillary hydrostatic pressure

C) increase in capillary hydrostatic pressure

D) decrease in pressure

E) decrease in valve functioning

34) The pressure at which the pulse can first be heard corresponds to the ________ pressure.

A) peak systolic

B) peak diastolic

C) mean arterial

D) average pulse

E) capillary hydrostatic

35) Considering the factors affecting blood flow, choose the accurate relationship.

A) Under normal circumstances, blood flow equals cardiac output.

B) When pressure rises, blood flow decreases.

C) When resistance increases, blood flow increases.

D) Resistance and blood flow are directly related.

E) Vessel length and blood flow are directly related.

36) If blood has low viscosity, which result would be likely under normal conditions?

A) Blood flows at higher pressures.

B) Blood flows against high resistance.

C) Blood flow cannot occur.

D) Blood flows at lower pressures.

E) Blood contains increased numbers of plasma proteins and suspended blood cells.

37) If venous pressures in the venules range from 17-21 mm Hg and pressures in the venae cavae range from 2-4 mm Hg, what is the pressure range of the driving force pushing blood through the venous system?

A) 2-4 mm Hg

B) 13-19 mm Hg

C) 15-17 mm Hg

D) 19-25 mm Hg

E) 21-23 mm Hg

38) In which of the following would vascular resistance be the least?

A) a vessel < 30 μm in diameter

B) a vessel 10 microns in diameter

C) a vessel 8 μm in diameter

D) a vessel 1 mm in diameter

E) a vessel 1 cm in diameter

39) Why is the osmotic pressure higher in the blood compared to that in the surrounding interstitial fluid?

A) Interstitial fluid contains more dissolved proteins than blood.

B) Blood has lower solute concentrations.

C) Interstitial fluid has higher solute concentrations.

D) There are equal concentrations of dissolved proteins in blood and interstitial fluid.

E) Blood contains more dissolved proteins than does interstitial fluid.

40) As blood travels from the aorta toward the capillaries,

A) cardiovascular pressure decreases.

B) vascular resistance decreases.

C) vascular flow increases.

D) viscosity decreases.

E) both cardiovascular pressure and vascular flow increase.