Ch 21 The Cardiovascular System: Blood Vessels and Hemodynamics

The what reflex helps maintain normal blood pressure in the brain; the what reflex governs general systematic blood pressure.

carotid sinus, aortic

In addition to the pressure created by contraction of the left ventricle, venous return is aided by the what, and the what, both of which depend on the presence of valves in the veins.

skeletal muscle pump, respiratory pump

T/F

Basoreceptors and chemoreceptors are located in the aorta and carotid arteries.

T

T/F

The most important method of capillary exchange is simple diffusion.

T

Which of the following are not true?

(1) Muscular arteries are also known as conducting arteries.

(2) Capillaries play a key role in regulating resistance.

(3) The flow of blood through true capillaries is controlled by precapillary sphincters.

(4) The lumen of an artery is larger than in a comparable vein.

(5) Elastic arteries help propel blood.

(6) The tunica media of arteries is thicker than the tunica media of veins.

(a) 2, 3, and 6

(b) 1, 2, and 4

(c ) 1, 2, 4, and 6

(d) 3, 4, and 5

(e) 1, 2, 3, and 4

b

Which of the following are true concerning capillary exchange?

(1) Large, lipid-insoluble molecules cross capillary walls by transcytosis.

(2) The blood hydrostatic pressure promotes reabsorption of fluid into the capillaries.

(3) If the pressures that promote filtration are greater than the pressures that promote reabsorption, fluid will move out of a capillary and into interstitial spaces.

(4) A negative net filtration pressure results in reabsorption of fluid from interstitial spaces into a capillarity.

(5) The difference in osmotic pressure across a capillary wall is due primarily to red blood cells.

(a) 1, 3, and 4

(b) 1, 2, 3, 4, and 5

(c ) 1, 2, 3, and 4

(d) 3 and 4

(e) 2, 4, and 5

a

Which of the following would not increase vascular resistance?

(1) vasodilation

(2) polycythemia

(3) obesity

(4) dehydration

(5) anemia

(a) 1 and

(b) 1, 3, and 4

(c ) 1 and 5

(d) 1, 4, and 5

(e) 1 only

c

Capillary exchange is enhanced by

(1) the slow rate of flow through the capillaries

(2) a small cross-sectional area

(3) the thinness of capillary walls

(4) the respiratory pump

(5) extensive branching, which increases the surface area

(a) 1, 2, 3, 4, and 5

(b) 1, 2, 3, and 5

(c ) 1 and 3

(d) 3 and 5

(e) 1, 3, and 5

e

Systematic vascular resistance depends on which of the following factors?

(1) blood viscosity

(2) total blood vessel length

(3) size of the lumen

(4) type of blood vessel

(5) oxygen concentration of the blood

(a) 1, 2, and 3

(b) 2, 3, and 4

(c ) 3, 4, and 5

(d) 1, 3, and 5

(e) 2, 4, and 5

a

Which of the following help regulate blood pressure and help control regional blood flow?

(1) baroreceptor and chemoreceptor reflexes

(2) hormones

(3) autoregulation

(4) H+ concentration of blood

(5) oxygen concentration of the blood

(a) 1, 2, and 4

(b) 2, 4, and 5

(c ) 1, 4, and 5

(d) 1, 2, 3, 4, and 5

(e) 3, 4, and 5

d