🍾🥂🍾2nd 💚💚

115) Heart rate is controlled by neurons of the cardiovascular center located in the C) medulla oblongata. D) hypothalamus. E) higher centers.

C

118) The ________ is the volume of blood in a ventricle at the beginning of systole. C) end-diastolic volume D) afterload E) preload

C

129) What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function? C) Sympathetic stimulation of the heart would increase. D) Heart rate would decrease. E) None of the answers is correct.

C

110) Which of the following would decrease heart rate? A) increased sympathetic stimulation of SA node B) decreased parasympathetic stimulation of nodal fibers C) increased levels of norepinephrine and/or epinephrine D) faster depolarization of the pacemaker potential E) increased parasympathetic stimulation of nodal fibers.

E

113) Acetylcholine slows the heart because it D) causes the pacemaker potential to depolarize more slowly. E) opens potassium ion channels in SA node cells and causes the pacemaker potential to depolarize more slowly.

E

111) Drugs that block the beta-one adrenergic receptors will B) decrease heart rate. C) increase contractility. D) increase cardiac output.

B

120) The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill. B) end-systolic volume C) end-diastolic volume

B

166) What effect would an increase in venous return have on the stroke volume? (Module 18.15B) B) An increase in venous return would fill the ventricles with more blood, increasing sarcomere length, which would increase the stroke volume. C) An increase in venous return would fill the ventricles with less blood, decreasing sarcomere length, which would increase the stroke volume.

B

122) Stroke volume depends on all of the following except C) the pressure required to pump blood into the aorta. D) end-systolic volume. E) cardiac output.

D

128) Cardiac output is increased by A) more sympathetic stimulation. B) increased end-diastolic volume. C) increased stroke volume. D) All of the answers are correct.

D

130) Which of these would cause stroke volume to increase? D) both when venous return is increased and when diastolic blood pressure is decreased E) both when venous return is decreased and when diastolic blood pressure is decreased

D