BIO 360 - Exam 3 - Chapter 15 Concept Check Questions

Answer 1

Veins from the brain do not require valves because blood flow is aided by gravity.

Answer 2

The carotid wave would arrive slightly ahead of the wrist wave because the distance from heart to carotid artery is shorter.

Answer 3

Pressure of 130/95 has the higher pulse pressure (35 mm Hg).

Answer 4

If heart rate increases, the relative time spent in diastole decreases. In that case, the contribution of systolic pressure to mean arterial pressure increases, and MAP increases.

Answer 5

Pulse pressure is 112−68=44 mm Hg. MAP is 68+1/3(44)≈83 mm Hg.

Answer 6

(d)

Answer 7

Extracellular K+ dilates arterioles, which increases blood flow (see Tbl. 15.2).

Answer 8

Epinephrine binding to myocardial β1-receptors increases heart rate and force of contraction. Epinephrine binding to β2-receptors on heart arterioles causes vasodilation.

Answer 9

α-Receptors have lower affinity for epinephrine than β2-receptors, so the β2-receptors dominate and arterioles dilate.

Answer 10

(a) The kidney has the highest blood flow per unit weight. (b) The heart has the lowest total blood flow.

Answer 11

The most likely ion is Na+ moving into the receptor cell.

Answer 12

This map should look exactly like Fig. 15.14b except that the directions of the arrows are reversed.

Answer 13

Stimulus: sight, sound, and smell of the T. rex. Receptors: eyes, ears, and nose. Integrating center: cerebral cortex, with descending pathways through the limbic system. Divergent pathways go to the cardiovascular control center, which increases sympathetic output to heart and arterioles. A second descending spinal pathway goes to the adrenal medulla, which releases epinephrine. Epinephrine on β2-receptors of liver, heart, and skeletal muscle arterioles causes vasodilation of those arterioles. Norepinephrine onto α-receptors in other arterioles causes vasoconstriction. Both catecholamines increase heart rate and force of contraction.

Answer 14

Loss of plasma proteins will decrease colloid osmotic pressure. As a result, hydrostatic pressure will have a greater effect in the filtration-absorption balance, and filtration will increase.

Answer 15

Using osmotic pressure rather than osmolarity allows a direct comparison between absorption pressure and filtration pressure, both of which are expressed in mm Hg.

Answer 16

If the left ventricle fails, blood backs up into the left atrium and pulmonary veins, and then into lung capillaries. Edema in the lungs is known as pulmonary edema.

Answer 17

Low-protein diets result in a low concentration of plasma proteins. Capillary absorption is reduced while filtration remains constant, resulting in edema and ascites.