Chapter 18

Which of these vessels returns blood to the left atrium of the heart? pulmonary veins pulmonary trunk superior vena cava coronary sinus

Which of these muscles is particularly associated with anchoring the right and left atrioventricular valves? myocardium trabeculae carneae papillary muscles pectinate muscles

The right atrioventricular valve prevents backflow of blood from the right ventricle into the __________. left ventricle pulmonary trunk right atrium left atrium

Which statement is correct regarding the ventricles? The left ventricle empties into the pulmonary circuit. The left ventricle has a thinner wall than the right ventricle. The right ventricle empties into the pulmonary trunk. The right ventricle forms a complete circle in cross section.

Which heart chamber receives oxygenated blood from the lungs? left ventricle left atrium right ventricle right atrium

What is happening during the "pause" phase when the heart is resting (relaxing)? Atria are contracting. Ventricles are filling. Valves are closing. Ventricles are contracting.

What causes the abnormal swishing or whooshing sound that is heard as blood regurgitates back into an atrium from its associated ventricle? aortic recoil semilunar valve closure blood turbulence pulmonary trunk expansion

The __________ valve is located between the right atrium and the right ventricle. pulmonary semilunar tricuspid mitral aortic semilunar

Which valve is located between the right atrium and ventricle? pulmonary semilunar valve bicuspid valve mitral valve tricuspid valve

In an ischemic heart, the affected cardiac muscle cells are likely to have an altered ______. number of Z discs number of desmosomes number of slow Ca+2 channels resting membrane potential

Which of the following does NOT deliver deoxygenated blood to the heart? coronary sinus superior vena cava inferior vena cava pulmonary veins

The right side of the heart is considered the systemic circuit pump. True False

Which of the following is NOT a difference between cardiac and skeletal muscle? Cardiac muscle does not use the sliding filament mechanism for contraction; skeletal muscle does. The plasma membranes of cardiac muscle cells interlock, but skeletal muscle fibers are independent. Cardiac muscle cells quickly die in the absence of oxygen; skeletal muscle cells are better able to adapt to oxygen deficiency. Cardiac muscle cells contain more mitochondria than do skeletal muscle cells.

What structures connect the individual heart muscle cells? trabaculae carneae anastomoses intercalated discs chordae tendineae

At what rate does the sinoatrial (SA) node depolarize? 30 times per minute 40 times per minute 50 times per minute 75 times per minute

Specifically, what part of the intrinsic conduction system stimulates the atrioventricular (AV) node to conduct impulses to the atrioventricular bundle? bundle branches subendocardial conducting network (Purkinje fibers) sinoatrial (SA) node interventricular septum

Which portion of the electrocardiogram represents the depolarization wave received by the atria from the sinoatrial (SA) node? QRS complex T wave P wave S-T segment

Which portion of the electrocardiogram represents the time during which the ventricles are in systole? QRS complex Q-T interval P wave T wave

During which portion of the electrocardiogram do the atrioventricular valves close, correlating with the first heart sound ("lub")? T wave P wave P-R interval R-S waves

Determine which of the following electrocardiogram (ECG) tracings is missing P waves but is otherwise regular. A B C D

Determine which ECG shows a normal sinus rhythm. A B C D

What heart problem would be experienced by an individual whose ECG is seen at C? The atria are not pumping blood. The heart would pump with too much pressure (hypertension). The heart is not pumping any blood at all. The ventricles are not reaching systole in every cardiac cycle.

The order of impulse conduction in the heart, from beginning to end, is __________. SA node, AV node, bundle of His, bundle branches, and Purkinje fibers SA node, bundle of His, AV node, bundle branches, and Purkinje fibers SA node, bundle branches, bundle of His, AV node, and Purkinje fibers SA node, bundle branches, AV node, bundle of His, and Purkinje fibers

The P wave on an electrocardiogram represents __________. ventricular depolarization atrial depolarization ventricular repolarization atrial repolarization

Which of the following structures collects the depolarization wave from the atria to pass it onto the ventricles? atrioventricular bundle bundle branches SA node AV node

Hypercalcemia could cause ______. increased osteoclast activity prolonged T wave hypersecretion of parathyroid hormone All of the listed responses are correct.

The first heart sound (the "lub" of the "lub-dup") is caused by __________. closure of the semilunar valves ventricular contraction closure of the atrioventricular valves atrial contraction

What causes heart sounds? heart valve closure blood flowing from the atria into the ventricles pressure of blood in the ventricles opening of heart valves

Which of the following would increase cardiac output? epinephrine decreased calcium during contraction high blood pressure parasympathetic stimulation

Blood within the pulmonary veins returns to the ________. right atrium left ventricle left atrium right ventricle

A foramen ovale ________. is a shallow depression in the interventricular septum connects the two atria in the fetal heart is a condition in which the heart valves do not completely close is a connection between the pulmonary trunk and the aorta in the fetus

When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________. tracing out where the auricles connect finding the papillary muscles locating the base noticing the thickness of the ventricle walls

A man enters the hospital complaining of chest pain. His history includes smoking, a stressful job, a diet heavy in saturated fats, lack of exercise, and high blood pressure. Although he is not suffering from a heart attack, his doctor explains to him that a heart attack is quite possible. What did the chest pain indicate? Why is this man a prime candidate for further complications? Angina pectoris. If the coronary arteries are occluded (atherosclerosis), the heart muscle could be deprived of oxygen, resulting in a heart attack. Myocardial infarction. If the coronary arteries are occluded (atherosclerosis), the heart muscle could be deprived of oxygen, resulting in a heart attack. Angina pectoris. If the coronary arteries are occluded (atherosclerosis), the heart muscle could be deprived of calcium, resulting in a heart attack.

The source of blood carried to capillaries in the myocardium would be the ________. fossa ovalis coronary sinus coronary arteries coronary veins

Tissues damaged by myocardial infarction are replaced by connective tissue. True False

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________. tetanic contractions might occur, which would stop the heart's pumping action it would be much longer before cardiac cells could respond to a second stimulation contractions would last as long as the refractory period pacemaker cells would cease to spontaneously depolarize

Compared to skeletal muscle, cardiac muscle ________. cells are larger than skeletal muscle cells has more nuclei per cell lacks striations has gap junctions that allow it to act as a functional syncytium

Damage to the ________ causes heart block. sinoatrial (SA) node atrioventricular (AV) bundle atrioventricular (AV) node atrioventricular (AV) valves

Which of the events below does NOT occur when the semilunar valves are open? Blood enters pulmonary arteries and the aorta. Ventricles are in diastole. AV valves are closed. Ventricles are in systole.

The atrioventricular (AV) valves are closed ________. while the atria are contracting when the ventricles are in diastole when the ventricles are in systole by the movement of blood from atria to ventricles

During the period of ventricular filling ________. pressure in the heart is at its peak blood flows mostly passively through the atria and the open atrioventricular (AV) valves into the ventricles the atria remain in diastole the aortic and pulmonary semilunar valves are ope

Calculate the stroke volume if the end diastolic volume (EDV) is 135 mL/beat and the end systolic volume (ESV) is 60 mL/beat. [Physiological factors that determine cardiac output.] 60 mL/beat 75 mL/beat 205 mL/beat 8100 mL/beat

Which of the following increases stroke volume? severe blood loss decrease in preload exercise decrease in end diastolic volume (EDV)

Which of the following factors does NOT influence heart rate? gender skin color age body temperature

When released in large quantities, thyroxine, a thyroid gland hormone, causes a sustained increase in heart rate. True False