Deck 12 (MR): The Heart

Question 1

Which of the following statements are true of the great vessels of the heart (Select all that apply)?

A)The pulmonary artery takes blood from the left ventricle to the lungs.
B)The superior vena cava returns blood from the upper body to the right atrium.
C)The inferior vena cava returns blood from the lower body to the left atrium.
D)The aorta takes blood from the right ventricle to the body.
E)The pulmonary veins return oxygenated blood from the lungs to both atria.
F)There are two caval veins and four pulmonary veins.

Answer 1

B,F

Question 2

Which of the following statements are true of the reflex arc for heart rate and blood pressure (Select all that apply)?

A)A drop in blood pressure is the stimulus to increase heart rate.
B)The receptors for this reflex are pressoreceptors located in the femoral artery.
C)The CNS center for this reflex is in the spinal cord.
D)The effector of this reflex is the myocardium.

Answer 2

A,D

Question 3

Which of the following statements are true of cardiac output (Select all that apply)?

A)Cardiac output equals stroke volume plus pulse.
B)Average resting cardiac output is approximately 5 liters per hour,and varies with the size of the person.
C)A certain level of cardiac output is necessary to maintain proper oxygenation of tissues.
D)Cardiac output may be decreased by severe hemorrhage.

Answer 3

C,D

Question 4

Which of the following statements are true of the nervous regulation of heart rate (Select all that apply)?

A)The cardiac centers are in the medulla of the brain.
B)Only the sympathetic nervous system has nerves to the heart muscle.
C)Heart rate changes in response to changes in blood pressure or blood gas levels.
D)Sympathetic nerve fibers to the heart are part of the vagus nerves.
E)The neurotransmitter norepinephrine decreases heart rate.f.The heart generates its own beat,but the neurotransmitter acetylcholine can increase the rate.

Question 5

Which of the following statements are true of coronary circulation (Select all that apply)?

A)The coronary arteries are branches of the ascending aorta.
B)The blood in the coronary arteries is high in oxygen.
C)Blockage of a coronary vessel may cause ischemia and necrosis of cardiac muscle.
D)The coronary veins merge into the coronary sinus,which empties blood into the left atrium.

Question 6

Which of the following statements are true of circulation through the heart (Select all that apply)?
a.The right side of the heart pumps blood to the body.
b.The left side of the heart pumps blood to the lungs.
c.The heart is really two pumps that work in alternating beats.
d.If the right side pump were to stop working,the left side pump could partially compensate.

Question 7

Which of the following statements are true of the cardiac conduction pathway (Select all that apply)?

A)The electrical events along the pathway are triggered by the mechanical events of the chambers.
B)The AV node depolarizes most rapidly.
C)The heart's natural pacemaker is the SA node.
D)The right and left bundle branches are in the interatrial septum.
E)Purkinje fibers are in the walls of the ventricles.
F)The AV bundle (of His)has a slower natural rate of contraction than does the AV node.

Question 8

Which of the following statements are true of the location and layers of the heart (Select all that apply)?

A)The heart is medial to the lungs and inferior to the diaphragm.
B)The fibrous pericardium is the thickest and outermost pericardial membrane.
C)The parietal and visceral pericardia are mucous membranes.
D)The endocardium lines the heart and prevents friction as the heart beats.
E)The apex of the heart is at the upper right of the mediastinum.
F)The myocardium is the thickest layer of the wall of the heart,and is responsible for contraction.

Question 9

Which of the following statements are true of the valves of the heart (Select all that apply)?

A)The pulmonary and aortic valves are important to prevent backflow of blood when the ventricles contract.
B)The right and left AV valves are important to prevent backflow of blood when the ventricles relax.
C)The pulmonary and aortic valves prevent backflow of blood from arteries to ventricles.
D)The edges of the semilunar valves are anchored by the chordae tendineae and papillary muscles.
E)The right and left AV valves prevent backflow of blood from atria to ventricles.
F)The valve openings are kept from stretching by the fibrous skeleton of the heart.

Question 10

Which of the following statements are true of the cardiac cycle (Select all that apply)?

A)The cardiac cycle is all of the events that take place in the heart in 1 minute.
B)Atrial systole is accompanied by ventricular diastole and is followed by ventricular systole.
C)Systole is the contraction phase,and diastole is the relaxation phase.
D)Most of the blood that moves from the atria to the ventricles is pumped.
E)About a third of the blood that moves from the ventricles to the arteries flows passively.
F)The AV valves are closed by the contraction of the ventricles.