A&P EXAM 2 CH 18
Damage to the ________ is referred to as heart block. Page Ref: 679 A) SA node B) AV valves C) AV bundle D) AV node
d
Norepinephrine acts on the heart by ________. Page Ref: 685-686 A) decreasing heart contractility B) causing a decrease in stroke volume C) blocking the action of calcium D) causing threshold to be reached more quickly
d
Tissues damaged by myocardial infarction are replaced by connective tissue. Page 670, 687
true
Trabeculae carneae are found in the ventricles and never the atria. Page Ref: 668
true
A) Epicardium B) Parietal layer C) Myocardium D) Endocardium 14) The inner lining of the heart. Page Ref: 664 15) Heart muscle. Page Ref: 663 16) Serous layer covering the heart muscle. Page Ref: 663 17) The outermost layer of the serous pericardium. Page Ref: 663
14d15c16a17b
A) Purkinje fibers B) AV bundle C) SA node D) AV node 18) The pacemaker of the heart. Page Ref: 677; Fig. 18.14 19) Found in the interventricular septum. Page Ref: 677 20) Network found in the ventricular myocardium. Page Ref: 677 21) The point in the conduction system of the heart where the impulse is temporarily delayed
18c19b20a21d
A) Pulmonary valves B) Aortic valve C) Mitral valve D) Tricuspid valve 22) Prevents backflow into the left ventricle. Page Ref: 670 23) Prevents backflow into the right atrium. 24) Prevents backflow into the left atrium. 25) Prevents backflow into the right ventricle. 26) AV valve with two flaps. 27) AV valve with three flaps
22b23d24c25a26c27d
A) Ischemia B) Ectopic focus C) Quiescent period D) Infarction E) Fibrillation 33) Heart muscle is deprived of oxygen. Page Ref: 675 34) Death of heart muscle cells. Page Ref: 670 35) A condition of rapid and irregular or out-of-phase contraction of heart muscle cells. Page 678 36) An abnormal pacemaker. Page Ref: 679 37) Total heart relaxation. Page Ref: 682
33a34d35e36b37c
Compared to skeletal muscle, cardiac muscle ________. Page Ref: 672-673 A) has gap junctions that allow it to act as a functional syncytium B) lacks striations C) has more nuclei per cell D) cells are larger than skeletal muscle cells
a
Foramen ovale ________. Page Ref: 688 A) connects the two atria in the fetal heart B) is a condition in which the heart valves do not completely close C) is a shallow depression in the interventricular septum D) is a connection between the pulmonary trunk and the aorta in the fetus
a
Hemorrhage with a large loss of blood causes ________. Page Ref: 682-684 A) a lowering of blood pressure due to change in cardiac output B) a rise in blood pressure due to change in cardiac output C) no change in blood pressure but a slower heart rate D) no change in blood pressure but a change in respiration
a
If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________. Page Ref: 675 A) decreased delivery of oxygen B) a decrease in the number of available mitochondria for energy production C) a lack of nutrients to feed into metabolic pathways D) an inadequate supply of lactic acid
a
If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________. Page Ref: 676-677 A) threshold is reached more quickly and heart rate would increase B) potassium channels compensate and no change in heart rate would occur C) heart rate would decrease, but blood pressure would rise due to the excess sodium present D) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle
a
Isovolumetric contraction ________. Page Ref: 682; Fig. 18.20 A) refers to the short period during ventricular systole when the ventricles are completely closed chambers B) occurs while the AV valves are open C) occurs immediately after the aortic and pulmonary valves close D) occurs only in people with heart valve defects
a
Select the correct statement about cardiac output. Page Ref: 682-684 A) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction. B) Decreased venous return will result in increased end diastolic volume. C) If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. D) Stroke volume increases if end diastolic volume decreases
a
Select the correct statement about the function of myocardial cells. Page Ref: 673-675 A) The entire heart contracts as a unit or it does not contract at all. B) Each cardiac muscle cell is innervated by a sympathetic nerve ending so that the nervous system can increase heart rate. C) The refractory period in skeletal muscle is much longer than that in cardiac muscle. D) The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.
a
The time of day most hazardous for heart attacks is ________. Page Ref: 685-686 A) morning B) noontime C) evening D) during sleep
a
Which of the events below does not occur when the semilunar valves are open? A) Ventricles are in diastole. B) Blood enters pulmonary arteries and the aorta. C) AV valves are closed. D) Ventricles are in systole. Page Ref: 670
a
) The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________. Page Ref: 668 A) pumps a greater volume of blood B) pumps blood against a greater resistance C) expands the thoracic cage D) sends blood through a smaller valve
b
Blood within the pulmonary veins returns to the ________. Page Ref: 668 A) right atrium B) left atrium C) right ventricle D) left ventricle
b
During contraction of heart muscle cells ________. Page Ref: 673-675 A) the action potential is initiated by voltage-gated slow calcium channels B) some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores C) the action potential is prevented from spreading from cell to cell by gap junctions D) calcium is prevented from entering cardiac fibers that have been stimulated
b
During the period of ventricular filling ________. Page Ref: 682 A) pressure in the heart is at its peak B) blood flows passively through the atria and the open AV valves into the ventricles C) the atria remain in diastole D) it is represented by the P wave on the ECG
b
If the vagal nerves to the heart were cut, the result would be that ________. Page Ref: 686 A) the heart would stop, since the vagal nerves trigger the heart to contract B) the heart rate would increase by about 25 beats per minute C) the AV node would become the pacemaker of the heart D) parasympathetic stimulation would increase, causing a decrease in heart rate
b
The tricuspid valve is closed ________. Page Ref: 682; Fig. 18.20 A) while the ventricle is in diastole B) when the ventricle is in systole C) while the atrium is contracting D) by the movement of blood from atrium to ventricle
b
When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________. Page Ref: 668 A) tracing out where the auricles connect B) noticing the thickness of the ventricle walls C) locating the apex D) finding the papillary muscles
b
Which vessel of the heart receives blood during right ventricular systole? Page Ref: 668, 682 A) venae cavae B) pulmonary trunk C) aorta D) pulmonary veins
b
) The left ventricular wall of the heart is thicker than the right wall in order to ________. A) accommodate a greater volume of blood B) expand the thoracic cage during diastole C) pump blood with greater pressure D) pump blood through a smaller valve Page Ref: 668
c
Small muscle masses attached to the chordae tendineae are the ________. Page Ref: 670 A) trabeculae carneae B) pectinate muscles C) papillary muscles D) venae cavae
c
The source of blood carried to capillaries in the myocardium would be the ________. A) coronary sinus B) fossa ovalis C) coronary arteries D) coronary veins Page Ref: 669
c
Select the correct statement about the heart valves. Page Ref: 670 A) The mitral valve separates the right atrium from the right ventricle. B) The tricuspid valve divides the left atrium from the left ventricle. C) Aortic and pulmonary valves control the flow of blood into the heart. D) The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
d
Select the correct statement about the structure of the heart wall. Page Ref: 663-664 A) The fibrous skeleton forms the bulk of the heart. B) Connective tissue in the heart wall aids in the conduction of the action potential. C) The heart chambers are lined by the endomysium. D) The myocardium is the layer of the heart that actually contracts.
d
The P wave of a normal electrocardiogram indicates ________. Page Ref: 679 A) ventricular repolarization B) ventricular depolarization C) atrial repolarization D) atrial depolarization
d
The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________. Page Ref: 670 A) ischemia B) pericarditis C) myocardial infarct D) angina pectoris
d
Which of the following is not an age-related change affecting the heart? Page Ref: 686-687 A) atherosclerosis B) decline in cardiac reserve C) fibrosis of cardiac muscle D) thinning of the valve flaps
d
Which of these vessels receives blood during ventricular systole? Page Ref: 682 A) aorta only B) pulmonary arteries only C) pulmonary veins only D) both the aorta and pulmonary trunk
d
) Autonomic regulation of heart rate is via two reflex centers found in the pons. Page Ref: 685
false
Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole. Page Ref: 669-670
false
Cardiac muscle has fewer mitochondria and depends less on a continual supply of oxygen than does skeletal muscle. Page Ref: 673
false
The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic valves. Page Ref: 681
false
The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the AV valve flaps. Page Ref: 670
false
Anastomoses among coronary arterial branches provide collateral routes for blood delivery to the heart muscle. Page Ref: 669
true
As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve. Page Ref: 687
true
Chronic release of excess thyroxine can cause a sustained increase in heart rate and a weakened heart. Page Ref: 686
true
Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues. Page Ref: 687
true
The left side of the heart pumps the same volume of blood as the right. Page Ref: 668
true
The myocardium receives its blood supply from the coronary arteries. Page Ref: 670
true
