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| 1 | |
Which of these structures is NOT found in the mediastinum? |
| | A) | esophagus |
| | B) | heart |
| | C) | lung |
| | D) | thymus gland |
| | E) | trachea |
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| 2 | |
Which of these descriptions of the heart's location is correct? |
| | A) | The heart lies obliquely in the mediastinum. |
| | B) | Its base is directed anteriorly and slightly superiorly. |
| | C) | Its apex is directed posteriorly and slightly inferiorly. |
| | D) | Two-thirds of the heart's mass lies to the right of the midline of the sternum. |
| | E) | all of these |
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| 3 | |
The epicardium |
| | A) | is also known as the parietal pericardium. |
| | B) | is a layer of cardiac muscle. |
| | C) | is the visceral pericardium. |
| | D) | lines the heart chambers. |
| | E) | is the pacemaker of the heart. |
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| 4 | |
The heart valves have a double layer of __________ with a layer of __________ in between. |
| | A) | epicardium, myocardium |
| | B) | epicardium, endocardium |
| | C) | myocardium, endocardium |
| | D) | endocardium, connective tissue |
| | E) | connective tissue, epicardium |
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| 5 | |
Musculi pectinati are found in the __________ ; trabeculae carneae are found in the __________ . |
| | A) | auricles, auricles |
| | B) | auricles, ventricles |
| | C) | ventricles, auricles |
| | D) | ventricles, ventricles |
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| 6 | |
Which of these structures deliver(s) blood to the left atrium? |
| | A) | coronary sinus |
| | B) | superior vena cava |
| | C) | inferior vena cava |
| | D) | pulmonary veins |
| | E) | pulmonary arteries |
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| 7 | |
The anterior interventricular artery is a branch of the |
| | A) | left pulmonary artery. |
| | B) | right pulmonary artery. |
| | C) | left coronary artery. |
| | D) | right coronary artery. |
| | E) | aorta. |
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| 8 | |
The valve located between the left atrium and left ventricle is the |
| | A) | aortic semilunar valve. |
| | B) | bicuspid (mitral) valve. |
| | C) | pulmonary semilunar valve. |
| | D) | tricuspid valve. |
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| 9 | |
Strong connective tissue strings that are attached to papillary muscles and to the cusps of the atrioventricular valves are |
| | A) | musculi pectinati. |
| | B) | chordae tendineae. |
| | C) | trabeculae carneae. |
| | D) | the skeleton of the heart. |
| | E) | the interventricular septum. |
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| 10 | |
Given these valves:
1. aortic semilunar valve
2. bicuspid (mitral) valve
3. pulmonary semilunar valve
4. tricuspid valve.
Arrange them in the order in which an erythrocyte would pass through them after returning to the heart from the left arm. |
| | A) | 1,2,3,4 |
| | B) | 2,3,1,4 |
| | C) | 3,1,2,4 |
| | D) | 3,4,2,1 |
| | E) | 4,3,2,1 |
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| 11 | |
The skeleton of the heart |
| | A) | electrically insulates the atria from the ventricles. |
| | B) | is composed of bones and cartilage. |
| | C) | is the location of the pacemaker. |
| | D) | is composed of calcified cardiac muscle. |
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| 12 | |
Which of these structures is NOT present in cardiac muscle cells? |
| | A) | desmosomes |
| | B) | gap junctions |
| | C) | smooth sarcoplasmic reticulum |
| | D) | terminal cisternae |
| | E) | transverse (T) tubules |
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| 13 | |
The group of modified cardiac muscle cells that delays action potentials between the atria and the atrioventricular bundle is called the |
| | A) | Purkinje fibers. |
| | B) | SA node. |
| | C) | bundle branches. |
| | D) | AV node. |
| | E) | apex. |
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| 14 | |
If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur? |
| | A) | The heart will stop. |
| | B) | The ventricles will contract, but the atria will stop. |
| | C) | Another part of the heart, possibly the AV node, will become the pacemaker. |
| | D) | The heart will beat faster. |
| | E) | The atria will keep contracting, but the ventricles will stop. |
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| 15 | |
Which of these statements concerning cardiac muscle is correct? |
| | A) | Cardiac muscle has more sarcoplasmic reticulum than skeletal muscle. |
| | B) | Cardiac muscle has a prolonged period of slow repolarization called the plateau phase. |
| | C) | Cardiac muscle has a shorter refractory period than skeletal muscle. |
| | D) | Depolarization of cardiac muscle occurs when K+ and Na+ diffuse into the cell. |
| | E) | All of these are correct. |
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| 16 | |
Action potentials pass rapidly from one cardiac muscle cell to another because of |
| | A) | intercalated disks and numerous gap junctions. |
| | B) | large nerves with branches going to each cardiac muscle cell. |
| | C) | the large voltage of cardiac action potentials. |
| | D) | the plateau phase of the action potential. |
| | E) | open Ca2+ channels. |
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| 17 | |
The depolarization phase of the cardiac muscle action potential occurs when |
| | A) | voltage-gated Ca2+ ion channels open. |
| | B) | voltage-gated K+ ion channels open. |
| | C) | voltage-gated Na+ ion channels open. |
| | D) | both b and c |
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| 18 | |
Early repolarization of cardiac muscle cells occurs when |
| | A) | voltage-gated Ca2+ ion channels open. |
| | B) | voltage-gated K+ ion channels open. |
| | C) | voltage-gated Na+ ion channels close. |
| | D) | both b and c |
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| 19 | |
Which of these conditions occur in the cardiac muscle cell during the plateau phase? |
| | A) | voltage-gated Ca2+ ion channels are open |
| | B) | voltage-gated K+ ion channels are open |
| | C) | voltage-gated Na+ ion channels are closed |
| | D) | all of these |
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| 20 | |
Which of these conditions occurs in the cardiac muscle cell during the final repolarization phase? |
| | A) | voltage-gated Ca2+ ion channels are open |
| | B) | voltage-gated K+ ion channels are open |
| | C) | voltage-gated Na+ ion channels are open |
| | D) | all of these |
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| 21 | |
Unlike other cardiac muscle cells, the movement of __________ into the pacemaker cells is primarily responsible for the depolarization phase of the action potential. |
| | A) | Ca2+ ions |
| | B) | K+ ions |
| | C) | Na+ ions |
| | D) | Cl- ions |
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| 22 | |
Which of these conditions results in a prepotential in pacemaker cells? |
| | A) | Na+ ions move into the cell through specialized Na+ ion channels. |
| | B) | Membrane permeability to K+ ions increases. |
| | C) | Voltage-gated Ca2+ ion channels close. |
| | D) | All of these are correct. |
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| 23 | |
In an EKG, the P wave represents |
| | A) | depolarization of the atria. |
| | B) | repolarization of the atria. |
| | C) | depolarization of the ventricles. |
| | D) | repolarization of the ventricles. |
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| 24 | |
During the QT interval of the EKG, the |
| | A) | atria contract and begin to relax. |
| | B) | atria relax. |
| | C) | ventricles contract and begin to relax. |
| | D) | ventricles relax. |
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| 25 | |
Which of these conditions is most likely to cause bradycardia? |
| | A) | ectopic action potentials in the atria |
| | B) | damage to the tricuspid valve |
| | C) | excessive sympathetic stimulation |
| | D) | excessive parasympathetic stimulation |
| | E) | too much coffee |
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| 26 | |
During the period of ejection in the cardiac cycle, the atrioventricular valves are __________ and the semilunar valves are __________ . |
| | A) | closed, closed |
| | B) | closed, open |
| | C) | open, closed |
| | D) | open, open |
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| 27 | |
Blood flows neither into nor out of the ventricles during |
| | A) | the period of isovolumic contraction. |
| | B) | the period of isovolumic relaxation. |
| | C) | systole. |
| | D) | diastole. |
| | E) | both a and b |
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| 28 | |
At the end of __________ , the ventricles are 70% filled. |
| | A) | active ventricular filling |
| | B) | passive ventricular filling |
| | C) | ventricular diastole |
| | D) | ventricular systole |
| | E) | atrial systole |
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| 29 | |
The average end-diastolic volume of the ventricles is about __________ , whereas the end-systolic volume is about __________ . |
| | A) | 125 mL, 55 mL |
| | B) | 125 mL, 0 mL |
| | C) | 0 mL, 55 mL |
| | D) | 0 mL, 125 mL |
| | E) | 55 mL, 125 mL |
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| 30 | |
During the period of ejection, the left ventricular pressure reaches a high point of approximately |
| | A) | 20 mm Hg. |
| | B) | 60 mm Hg. |
| | C) | 80 mm Hg. |
| | D) | 100 mm Hg. |
| | E) | 120 mm Hg. |
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| 31 | |
The second heart sound, described as "dupp" is actually the sound of the |
| | A) | atria contracting. |
| | B) | ventricles contracting. |
| | C) | atrioventricular valves closing. |
| | D) | semilunar valves closing. |
| | E) | heart slapping the liver. |
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| 32 | |
If the heart rate for a patient is 80 bpm, and her stroke volume is 70 mL/beat, then her cardiac output is |
| | A) | O.87 mL/min |
| | B) | 1.1 mL/min. |
| | C) | 10 mL/min. |
| | D) | 56 mL/min. |
| | E) | 5600 mL/min |
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| 33 | |
Preload |
| | A) | is the extent to which the ventricular walls are stretched. |
| | B) | if increased, causes a decrease in cardiac output. |
| | C) | is the pressure in the aorta which contracting ventricles must overcome. |
| | D) | is part of the extrinsic regulation of the heart. |
| | E) | all of these. |
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| 34 | |
Increased venous return to the heart causes increased |
| | A) | stroke volume. |
| | B) | preload. |
| | C) | cardiac output. |
| | D) | force of contraction. |
| | E) | all of these. |
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| 35 | |
Parasympathetic nerve fibers |
| | A) | are carried to the heart through the Accessory nerve (XI). |
| | B) | extend to terminal ganglia within the wall of the heart. |
| | C) | release the neurotransmitter norepinephrine. |
| | D) | if stimulated, result in an increased heart rate. |
| | E) | if stimulated, greatly increase stroke volume. |
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| 36 | |
When normal arterial blood pressure decreases, baroreceptors cause a response that |
| | A) | decreases heart rate. |
| | B) | decreases stroke volume. |
| | C) | returns blood pressure to normal. |
| | D) | results in parasympathetic stimulation of the heart. |
| | E) | all of these. |
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| 37 | |
If blood pH decreases and blood carbon dioxide increases, |
| | A) | heart rate increases. |
| | B) | stroke volume decreases. |
| | C) | increased parasympathetic stimulation of the heart occurs. |
| | D) | the change is detected by chemoreceptors in the pulmonary arteries. |
| | E) | all of these. |
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| 38 | |
Increased sympathetic stimulation of the heart |
| | A) | increases the force of ventricular contraction. |
| | B) | opens a larger number of calcium slow channels. |
| | C) | increases the heart rate. |
| | D) | increases cardiac output. |
| | E) | all of these. |
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| 39 | |
Generally, an increase in extracellular Ca2+ ions causes __________ force of contraction, and __________ heart rate. |
| | A) | decreased, decreased |
| | B) | decreased, increased |
| | C) | increased, decreased |
| | D) | increased, increased |
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| 40 | |
Excess K+ ions in cardiac tissue cause heart rate and stroke volume to __________ and decreased extracellular K+ ions result in a __________ in heart rate. |
| | A) | decrease, decrease |
| | B) | decrease, increase |
| | C) | increase, decrease |
| | D) | increase, increase |
| | E) | be unchanged, increase |
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