CHP 13 A&P
A decrease in afterload will lead to which of the following? 74) ______ A) increased stroke volume B) decreased stroke volume C) decreased heart rate D) increased heart rate E) decreased cardiac output
A
Age, general health, level of muscular activity and emotional state can all affect cardiac output and heart rate.
A
All veins return blood to the heart
A
An abnormally slow firing of the SA node causes bradycardia
A
An increase in venous return would result in a(n) 72) ______ A) increased end-diastolic volume. B) decreased end-systolic volume. C) increased end-systolic volume. D) increase mid-systolic volume. E) decreased end-diastolic volume.
A
Blood is ejected from the left ventricle once pressure within the 51) ______ A) ventricle is greater than pressure within the aorta. B) ventricle is less than pressure within the aorta. C) ventricle is greater than pressure within the pulmonary artery. D) ventricle is less than pressure within the pulmonary artery. E) muscles of the pulmonary semilunar valve relax.
A
Calcium entering the cell during the plateau phase of the ventricular cell action potential triggers calcium release from the sarcoplasmic reticulum.
A
Calcium movement into the cell causes the rapid depolarization of the autorhythmic cell action potential, whereas sodium movement into the cell causes the rapid depolarization of the contractile cell action potential
A
During recording of an ECG, a depolarization that travels toward a positive lead will cause an upward deflection.
A
Given a constant pressure, the greater the radius of the vessel, the greater the tension on the vessel walls
A
Ischemia is a condition in which blood flow in a tissue is insufficient to keep up with metabolic demand.
A
Keeping blood on the left side of the heart from mixing with the blood on the right side is a function of what structure(s)? 1) _______ A) septum B) apex C) valves D) chordae tendineae E) arteries
A
Normal resting heart rate is around 70 beats per minute due to the SA node. If the SA node fails, what would you expect the heart beats per minute to be? 22) ______ A) 50 beats per minute B) 10-20 beats per minute C) If the SA node fails the individual will go into heart failure and therefore there will be no heart rate. D) 70 beats per minute as the AV node takes over for the SA node E) 30-40 beats per minut
A
Prolapse involves improper alignment of the atrioventricular valve such that one or more of the cusps are pushed into the atrium by the pressure developed in the ventricle.
A
Regulation of the heart (or any organ or tissue) by neural input, circulating hormones, or any other factor originating from outside the organ is referred to as ________ control. 58) ______ A) extrinsic B) neurogenic C) intrinsic D) myogenic E) voluntary
A
The Q-T interval is the time from the onset of the QRS complex to the end of the T wave which measures 36) ______ A) the time of ventricular systole. B) the amount of time between each heartbeat. C) the time of ventricular diastole. D) the time of atrial diastole. E) the time of atrial systole
A
The cardiac cycle represents one heartbeat.
A
The contractile cycle of the heart normally originates from a pacemaker cell within the sinoatrial node
A
The heart is regulated by both intrinsic and extrinsic mechanisms.
A
The resting cardiac output for both the left and right ventricles is approximately 5.0 liters/minute
A
The term autorhythmicity refers to the heart's ability to 17) ______ A) generate its own contractile cycle. B) conduct action potentials along the conduction pathway. C) originate its contraction neurogenically. D) act as a functional syncytium. E) intrinsically modify its contractility
A
Under resting conditions, heart rate is primarily under the control of what control system? 63) ______ A) the parasympathetic nervous system B) epinephrine C) intrinsic mechanisms D) the sympathetic nervous system E) the somatic nervous system
A
What is occurring during ventricular ejection? 44) ______ A) The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles. B) The AV and semilunar valves are closed as ventricular pressure is increasing. C) The AV and semilunar valves are open as blood is leaving the ventricles. D) The AV valves are open and the semilunar valves are closed as ventricular pressure is. increasing E) The AV valves are open and the semilunar valves are closed as blood is leaving the ventricles.
A
What is the primary function of the AV and semilunar valves? 14) ______ A) to permit blood to flow forward while preventing it from flowing backward B) to keep the right and left sides of the heart separated C) to coordinate the autorhythmic movements of the heart D) to control the speed at which blood enter and leaves the heart E) The opening and closing of the valves creates the normal patterns of an EKG.
A
What phase of the cardiac cycle is the heart in when all four valves of the heart are closed and ventricular pressure is building, but is not yet great enough to open a valve? 46) ______ A) isovolumetric contraction B) isovolumetric relaxation C) ventricular ejection D) ventricular filling E) none
A
What structure provides the pathway for the movement of electrical current between the cells of the conduction pathway and the ventricular muscle fibers? 18) ______ A) gap junctions B) potassium channels C) desmosomes D) funny channels E) sodium channels
A
What two major regions of the heart contain a concentration of pacemaker cells? 16) ______ A) sinoatrial node and atrioventricular node B) sinoatrial node and bundle of His C) bundle of His and atrioventricular node D) sinoatrial node and Purkinje fibers E) bundle of His and Purkinje fibers
A
Where is the SA node located? 78) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
A
Which channel type allows ion movement out of the cell during repolarization of the autorhythmic cells? 86) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
A
Which component of an ECG represents atrial depolarization? 91) ______ A) P wave B) P-R interval C) T wave D) Q-T interval E) QRS complex
A
Which heart structure receives deoxygenated blood from veins? 76) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
A
Which of the following best describes the effect of sympathetic activity on ventricular contractile cells? 66) ______ A) The rates of contraction and relaxation and the force of contraction all increase. B) The force of contraction increases, whereas the rates of contraction and relaxation are not affected. C) The rates of contraction and relaxation both decrease, whereas the force of contraction increases. D) The rates of contraction and relaxation both increase, whereas the force of contraction decreases. E) The rate of contraction and the force of contraction both increase, whereas the rate of relaxation decreases.
A
Which of the following components of an ECG represents atrial depolarization? 32) ______ A) P wave B) QRS complex C) T wave D) PQ interval E) TQ segment
A
Which of the following is responsible for the repolarization of pacemaker cells? 26) ______ A) an increase in PK B) a decrease in PK C) an increase in PCa D) an increase in PNa E) a decrease in PNa
A
Which of the following is true of the ventricular filling phase of the cardiac cycle? 45) ______ A) Ventricular pressure is less than aortic pressure. B) Ventricular pressure is greater than atrial pressure. C) Ventricular pressure is decreasing. D) Ventricular filling occurs during systole. E) All valves in the heart are open
A
Which statement best describes parallel flow in the circulatory system? 6) _______ A) The organs of the body are arranged in a parallel circuit to allow adequate flow and pressure to all body systems and maintain homeostasis of blood pressure. B) Parallel flow refers to the flow of electrical impulses in the heart. C) Parallel flow refers to deoxygenated blood only and not to oxygenated blood. D) Parallel flow refers to the flow of blood just to the heart itself, which keeps it oxygenated at all times. E) In the systemic circuit blood flows from one organ directly to the next, hence in parallel.
A
Which statement best describes why clinicians use a defibrillator? 42) ______ A) The applied current depolarizes all the muscle cells at the same time, returning synchronous electrical activity to the heart. B) A defibrillator takes the place of the SA node and must be applied every minute to keep the heart rate normal until it regains its strength and beats on its own. C) The ventricles of the heart are so large that only a strong current can make them depolarize, which is needed in order for them to contract and get blood to the body. D) The applied current opens up voltage gated calcium channels in the atria causing the heart to begin a new P wave. E) The applied current repolarizes the cells of the heart, hence resetting the heart for normal rhythm
A
A heart attack is also known as myocardial ischemia
B
Abnormal electrical activity of the heart is called myocardial infarction.
B
All veins contain deoxygenated blood.
B
An electrocardiogram recording is the same thing as an action potential
B
Arteries are vessels that always carry oxygenated blood.
B
Arteries have a high compliance compared to veins.
B
Atrial fibrillation is usually fatal if not treated immediately.
B
Blood supply to the heart comes from 7) _______ A) cerebral arteries. B) coronary arteries. C) blood within the ventricles. D) aorta. E) blood within the atria
B
Cardiac output is determined by what two variables? 57) ______ A) preload and afterload B) heart rate and stroke volume C) end-diastolic volume and end-systolic volume D) heart rate and ejection fraction E) stroke volume and ejection fraction
B
Contractile activity of cardiac muscle is neurogenic
B
Deoxygenated blood is blue.
B
During isovolumetric contraction, which chamber has the greatest pressure? 82) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
B
In what phase is the cardiac cycle when the AV valves are open and semilunar valves are closed? 98) ______ A) atrial contraction B) ventricular filling C) isovolumetric contraction D) isovolumetric relaxation E) ventricular ejection
B
On average, women have anatomically larger hearts than men.
B
The R-R interval is the time between the peaks of two successive QRS complexes and represents 38) ______ A) atrial diastole. B) the amount of time between heartbeats. C) atrial systole. D) ventricular diastole. E) ventricular systole.
B
The T-Q segment is the time from the end of the T wave to the beginning of the QRS complex which measures the time 37) ______ A) of ventricular systole. B) of ventricular diastole. C) between heartbeats. D) of atrial diastole. E) of atrial systole
B
The initial depolarization that occurs in pacemaker cells is caused by closing of ________ channels and opening of ________ channels. 106) _____ A) sodium : T-type calcium B) potassium : funny C) sodium : L-type calcium D) potassium : T-type calcium E) sodium : funny
B
The muscular wall of the right ventricle is thicker than that of the left ventricle because it develops a greater pressure in order to deliver blood to the organs of the body
B
The period of ventricular contraction is called ________, whereas the period of ventricular relaxation is called ________. 108) _____ A) action potential : refractory period B) systole : diastole C) diastole : systole D) V fib : A fib E) action potential : graded potential
B
The repolarization of the ventricle is reflected in the ________ of the electrocardiogram. 110) _____ A) P wave B) T wave C) QRS complex D) R-R interval E) P-Q interval
B
Ventricular contraction begins at the top of the heart and travels downward to its apex.
B
What chamber empties into the aorta? 80) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
B
What chamber has the thickest myocardium? 81) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
B
When blood moves through the body it travels in a circular pattern. The general pattern of blood flow follows which sequence of vessels as it leaves the heart? 3) _______ A) arteries, veins, venules, arterioles, capillaries B) arteries, arterioles, capillaries, venules, veins C) veins, venules, capillaries, arterioles, arteries D) arterioles, arteries, capillaries, venules, veins E) veins, capillaries, venules, arterioles, arteries
B
Which channel type allows calcium movement into the cell during the late spontaneous depolarization in autorhythmic cells? 85) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
B
Which of the following components of an ECG represents ventricular depolarization? 33) ______ A) P wave B) QRS complex C) T wave D) PQ interval E) TQ segment
B
Which of the following describes the effect of end-diastolic volume on stroke volume? 67) ______ A) A decrease in end-diastolic volume creates a vacuum drawing more blood into the ventricle increasing stroke volume. B) An increase in end-diastolic volume stretches ventricular muscle cells to lengths closer to optimum, increasing the strength of contraction and thereby increasing stroke volume. C) A decrease in end-diastolic volume allows ventricular muscle cells to relax more during diastole, allowing more blood to return to the heart increasing stroke volume. D) A decrease in end-diastolic volume allows cardiac muscle to relax, conserving energy for the next contraction, thereby increasing stroke volume of that next contraction. E) An increase in end-diastolic volume stretches ventricular muscle cells to lengths greater than optimum, decreasing the strength of contraction and thereby decreasing stroke volume.
B
Which of the following is a FALSE statement about sympathetic activity to the SA node? 62) ______ A) Funny channel opening is enhanced. B) Potassium channel closing is enhanced. C) cAMP levels in the pacemaker cells increases. D) The rate of spontaneous depolarization is increased. E) Norepinephrine binds to beta1adrenergic receptors.
B
Which of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells? 25) ______ A) an increase in PK B) an increase in PCa C) an increase in PNa D) a decrease in PK E) a decrease in PNa
B
Which of the following statements best describes a portal system? 8) _______ A) The portal system refers to ports located in the veins (which does not allow for the backflow of blood). B) Blood flows from one capillary bed to another, bypassing general circulation. C) The portal system allows enough pressure to be generated to close the foramen ovale in the fetal heart. D) The portal system is the same as parallel flow. E) Blood flows in one direction throughout the circulatory system
B
Which of the following statements best describes the function of the chordae tendineae? 13) ______ A) The chordae tendineae act like a parachute and capture blood as it enters the right ventricle. B) They pull downward on the valve cusps, thereby preventing the AV valves from being pushed into the atria (prolapsing). C) They open and close the AV valve due to the movement of the papillary muscle during contraction. D) The chordae tendineae generate autorhythmicity within the heart. E) When the heart contracts, the chordate tendineae separate the flow of blood from the right and left sides of the heart.
B
Why do AV nodal cells NOT determine the heart rate under normal circumstances? 21) ______ A) They depolarize faster than all other conducting fibers. B) As depolarization initiated in the SA node reaches the AV node, it leaves the AV node in a refractory state. C) They slow conduction of the wave of excitation. D) They depolarize slower than all other conducting fibers. E) The AV node is connected to the SA node, but not to other conducting fibers in the heart.
B
Although blood is a fluid, nearly half its volume is composed of cells. The most numerous cells are ________. The remainder of the cells are ________, which help the body defend itself against foreign particles and microorganisms. 4) _______ A) erythrocytes : platelets B) platelets : leukocytes C) erythrocytes : leukocytes D) leukocytes : erythrocytes
C
Blood is moved through the pulmonary vasculature by pressure generated within the 103) _____ A) right atrium. B) aorta. C) right ventricle. D) left atrium. E) left ventricle
C
Conduction through which of the following is slow to allow atria to contract before the ventricles? 20) ______ A) SA node B) atria C) AV node D) AV bundle (bundle of His) E) Purkinje fibers
C
During isovolumetric relaxation, 43) ______ A) the AV and semilunar valves are open and ventricular pressure is decreasing. B) the AV and semilunar valves are closed and ventricular pressure is increasing. C) the AV and semilunar valves are closed and ventricular pressure is decreasing. D) the AV valves are open, the semilunar valves are closed, and ventricular pressure is decreasing. E) the AV and semilunar valves are open and ventricular pressure is increasing
C
During repolarization (phase 3) of a contractile cell action potential, 28) ______ A) only sodium permeability is increased. B) only calcium permeability is increased. C) only potassium permeability is increased. D) sodium and calcium permeability are both increased. E) sodium and potassium permeability are both increased
C
Ejection of blood from the right ventricle will continue until 48) ______ A) pressure in the aorta is less than pressure in the right ventricle. B) the pulmonary semilunar valve contracts, inducing closure. C) pressure in the pulmonary artery is greater than pressure in the right ventricle. D) pressure in the aorta is greater than pressure in the right ventricle. E) pressure in the pulmonary artery is less than pressure in the right ventricle
C
If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart? 23) ______ A) The individual would be in heart failure or have a myocardial infarction due to the lack of a beating heart. B) The vagus nerve takes over and maintains a normal heart rate. C) The rate would be 30-40 beats per minute due to the concentration of pacemaker cells in the Purkinje fibers. D) The heart is autorhythmic therefore it continually beats even after death because death is defined as a lack of brain waves. E) The sympathetic nervous system takes over and maintains normal heart rate
C
If damage to the AV node slowed down conduction through this tissue, what would be observed on an ECG? 39) ______ A) a longer P wave B) a larger P wave C) a longer PR interval D) a wider QRS complex E) an inverted T wave
C
The circulatory system consists of two divisions and is supplied with blood by different sides of the heart. The right heart supplies blood to the ________ circuit, whereas the left heart supplies blood to the ________ circuit. 5) _______ A) superior (upper body) : inferior (lower body) B) arterial : venule C) pulmonary : systemic D) oxygenated : deoxygenated E) systemic : pulmonary
C
The depolarization of the action potential in the pacemaker cells is driven by the rapid influx of ________ ions through ________ channels. 107) _____ A) sodium : funny B) potassium : funny C) calcium : L-type calcium D) sodium : T-type calcium E) potassium : T-type calcium
C
The end-diastolic volume minus the end-systolic volume is the 53) ______ A) cardiac output. B) total ventricular volume. C) stroke volume. D) total atrial volume. E) ejection fraction.
C
The increased aortic pressure that occurs during systole reflects a(n) 52) ______ A) decreased stiffness of the aorta. B) decreased volume of blood within the aorta. C) increased volume of blood in the aorta. D) decreased resistance of the vasculature. E) increased resistance of the vasculature
C
The mitral valve separates what chamber from its associated ventricle? 79) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
C
The opening and closure of the atrioventricular and semilunar valves is driven by 11) ______ A) contraction of muscles attached to the valves. B) contraction of the ventricle and atria that pull the valves into place. C) differences in pressure across the valve. D) contraction of the valve. E) contraction and relaxation of the valve
C
The preload is approximately the same as the ________ pressure. 70) ______ A) aortic systolic B) end-systolic C) end-diastolic D) atrial E) aortic diastolic
C
The small increase in ventricular pressure observed late in diastole is caused by 50) ______ A) ventricular relaxation. B) blood moving into the atria from vena cava. C) atrial contraction. D) atrial relaxation. E) ventricular contraction
C
What component of the conduction pathway transmits the action potential to the ventricular contractile cells? 104) _____ A) SA node B) bundle of His C) Purkinje fibers D) nodal pathways E) AV node
C
What is the pacemaker of the heart? 105) _____ A) bundle of His B) AV node C) SA node D) nodal pathways E) Purkinje fibers
C
Which channel type allows sodium movement into the cell during the early spontaneous depolarization in autorhythmic cells? 84) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
C
Which component of an ECG represents ventricular repolarization? 92) ______ A) P wave B) P-R interval C) T wave D) Q-T interval E) QRS complex
C
Which heart structure receives blood from the pulmonary veins? 77) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
C
Which of the following components of an ECG represents ventricular repolarization? 34) ______ A) P wave B) QRS complex C) T wave D) PQ interval E) TQ segment
C
Which of the following decreases heart rate? 75) ______ A) increase in stroke volume B) increase in venous pressure C) increase in parasympathetic activity D) increase in sympathetic activity E) increase in filling time
C
Which of the following would NOT result from an increase in ventricular contractility? 65) ______ A) increased proportion of end-diastolic volume that is ejected B) increased stroke volume C) decreased end-diastolic volume D) decreased end-systolic volume E) increased ejection fraction
C
Blood returns to the left atrium via what blood vessels? 101) _____ A) aorta B) coronary artery C) iliac vein D) pulmonary veins E) superior and inferior vena cavae
D
Closure of the atrioventricular valve occurs when 12) ______ A) pressure inside the ventricle is less than pressure inside the atrium. B) the valve contracts. C) the papillary muscle contracts. D) pressure inside the ventricle is greater than pressure inside the atrium. E) the atrium contracts.
D
Given end-diastolic volume = 130 mL and end-systolic volume = 50 mL, what is the stroke volume and ejection fraction? 55) ______ A) SV = 180 mL, EF = 0.38 B) SV = 180 mL, EF = 0.61 C) SV = 50 mL, EF = 0.61 D) SV = 80 mL, EF = 0.61 E) SV = 80 mL, EF = 0.38
D
In an ECG recording, the RR interval is 0.5 seconds. What is the heart rate? 40) ______ A) 60 beats/min B) 100 beats/min C) 50 beats/min D) 120 beats/min E) 30 beats/min
D
In what phase is the cardiac cycle when all four valves are closed and pressure in the ventricle is decreasing? 96) ______ A) atrial contraction B) ventricular filling C) isovolumetric contraction D) isovolumetric relaxation E) ventricular ejection
D
Starling curves plot ________ against ________. 69) ______ A) heart rate : end-systolic volume B) heart rate : end-diastolic volume C) cardiac output : end-diastolic volume D) stroke volume : end-diastolic volume E) stroke volume : end-systolic volume
D
The SA node is innervated by the 60) ______ A) somatic nervous system only. B) sympathetic nervous system only. C) parasympathetic nervous system only. D) sympathetic and parasympathetic nervous systems. E) sympathetic, parasympathetic, and somatic nervous systems.
D
The increase in ventricular volume early in diastole reflects the 49) ______ A) back-flow of blood from the aorta. B) contraction of the atria moving blood into the ventricle. C) relaxation of the ventricle. D) passive movement of blood through the atrium and into the ventricle. E) increased stiffness of the heart.
D
The primary site of exchange between blood and interstitial fluid occurs across what type of blood vessel? 2) _______ A) arterioles B) venules C) veins D) capillaries E) arteries
D
The second heart sound coincides with the beginning of which period in the cardiac cycle? 100) _____ A) atrial contraction B) ventricular filling C) isovolumetric contraction D) isovolumetric relaxation E) ventricular ejection
D
The volume of blood that is pumped by the heart every minute is determined by the equation 111) _____ A) SV = EDV - ESV. B) T = PR/2. C) EF = EDV - ESV. D) CO = HR × SV. E) BP - PR × VL.
D
What causes the rapid depolarization phase of a contractile cell action potential? 27) ______ A) calcium movement into the cell B) sodium movement out of the cell C) potassium movement into the cell D) sodium movement into the cell E) calcium movement out of the cell
D
What causes the sounds that one hears as the heart beats? 56) ______ A) the snapping of the valves into a closed position B) the snapping of the valves into the open position C) the turbulence created as the valves open D) the turbulence created as the valves close E) the bulk movement of blood into and out of the ventricle
D
What channels open during the plateau phase of the cardiac contractile cell action potential? 88) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
D
What is the function of the sodium-calcium exchanger in cardiac muscle? 31) ______ A) interact with troponin to initiate cross-bridge cycling B) trigger the release of calcium from the sarcoplasmic reticulum C) remove calcium from the cytosol by transporting it into the sarcoplasmic reticulum D) remove calcium from the cytosol by transporting it to the extracellular fluid thereby relaxing the muscle E) depolarize the cell
D
What structure separates the thoracic cavity from the abdominal cavity? 9) _______ A) lungs B) intestines C) heart D) diaphragm E) liver
D
Which chamber is connected to the pulmonary arteries? 83) ______ A) right atrium B) left ventricle C) left atrium D) right ventricle E) AV bundle (bundle of His)
D
Which channel type is responsible for ion movement during the depolarization phase of the autorhythmic cell action potential? 87) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
D
Which component of an ECG represents the AV nodal conduction time? 95) ______ A) T-Q segment B) T wave C) QRS complex D) P-R interval E) Q-T interval
D
Which component of an ECG represents ventricular systole? 93) ______ A) P wave B) P-R interval C) T wave D) Q-T interval E) QRS complex
D
Which of the following describes second-degree heart block? 41) ______ A) Not every ventricular contraction is preceded by an atrial contraction. B) There is a longer delay between atrial contraction and ventricular contraction. C) The atria no longer contract. D) Not every atrial contraction is followed by a ventricular contraction. E) The ventricles no longer contract
D
Which of the following is an effect of parasympathetic activity to the heart? 61) ______ A) Postganglionic neurons release acetylcholine, which binds to nicotinic cholinergic receptors in the SA node. B) Heart rate is increased. C) SA nodal cells are depolarized. D) The rate of spontaneous depolarization in SA nodal cells decreases. E) cAMP is activated.
D
Which of the following is the correct conduction pathway through the heart? 19) ______ A) Purkinje fibers, bundle of His, bundle branches, SA node, AV node B) Bundle of His, bundle branches, Purkinje fibers, SA node, AV node C) SA node, Purkinje fibers, AV node, bundle of His, bundle branches D) SA node, AV node, bundle of His, bundle branches, Purkinje fibers E) AV node, SA node, bundle branches, bundle of His, Purkinje fibers
D
Which of the following structures is poorly innervated by the parasympathetic nervous system and, therefore, an increase in parasympathetic activity has little effect on this structure? 59) ______ A) conduction pathway B) Purkinje fibers C) sinoatrial node D) ventricles E) atrioventricular node
D
Which of the following variables is NOT involved in determining ventricular preload? 73) ______ A) venous return B) atrial pressure C) filling time D) afterload E) central venous pressure
D
An increase in heart rate can be mediated through which of the following? 64) ______ A) a decrease in parasympathetic nervous activity only B) a decrease in sympathetic activity only C) an increase in sympathetic activity only D) an increase in parasympathetic activity and a decrease in sympathetic activity E) a decrease in parasympathetic activity and an increase in sympathetic activity
E
During which phase of the cardiac cycle are all four heart valves open? 47) ______ A) isovolumetric relaxation B) ventricular ejection C) isovolumetric contraction D) ventricular filling E) none
E
In what phase is the cardiac cycle when the semilunar valves are open and AV valves are closed? 99) ______ A) atrial contraction B) ventricular filling C) isovolumetric contraction D) isovolumetric relaxation E) ventricular ejection
E
In what phase of the cardiac cycle does ventricular pressure exceed aortic pressure? 97) ______ A) atrial contraction B) ventricular filling C) isovolumetric contraction D) isovolumetric relaxation E) ventricular ejection
E
Opening of what channels is responsible for the depolarization phase of the cardiac contractile cell action potential? 89) ______ A) potassium channels B) T-type calcium channels C) funny channels D) L-type calcium channels E) voltage-gated sodium channels
E
The P wave of the electrocardiogram is created by 109) _____ A) atrial repolarization. B) atrial hyperpolarization. C) ventricular depolarization. D) ventricular repolarization. E) atrial depolarization.
E
The rapid depolarization phase of a pacemaker cell action potential is caused by movement of 24) ______ A) calcium through T-type channels. B) sodium through funny channels. C) sodium and calcium through funny channels. D) potassium through funny channels. E) calcium through L-type channels
E
The volume of blood ejected from the ventricle with each contraction can be described by the equation 54) ______ A) (pulse pressure) - (end-diastolic volume). B) (end-systolic volume) - (stroke volume). C) (ejection fraction) × (end-diastolic volume). D) (stroke volume) - (end-diastolic volume). E) (end-diastolic volume) - (end-systolic volume).
E
What are the three layers of the heart, from inside to outside? 102) _____ A) myocardium, endothelium, and epicardium B) epicardium, myocardium, and endothelium C) myocardium, epicardium, and endothelium D) endothelium, epicardium, and myocardium E) endothelium, myocardium, and epicardium
E
What is the equation relating stroke volume (SV), end-diastolic volume (EDV), and end-stroke volume (ESV)? 112) _____ A) SV = EDV/ESV B) SV = EDV + ESV/3 C) SV = EDV + ESV D) SV = EDV × ESV E) SV = EDV - ESV
E
Whereas the contractile activity of skeletal muscle is called ________, that of cardiac muscle is ________ because the contraction originates within the musculature itself. 15) ______ A) voluntary : involuntary B) extrinsic : intrinsic C) somatic : autorhythmic D) somatic : autonomic E) neurogenic : myogenic
E
Which chamber of the heart has the thickest musculature? 10) ______ A) left ventricle B) right ventricle C) right atrium D) left atrium E) Both ventricles have equal thickness and are thicker than the atria
E
Which component of an ECG represents ventricular depolarization? 90) ______ A) P wave B) P-R interval C) T wave D) Q-T interval E) QRS complex
E
Which component of an ECG represents ventricular diastole? 94) ______ A) Q-T interval B) QRS complex C) T wave D) P-R interval E) T-Q segment
E
Which of the following factors determines preload? 71) ______ A) parasympathetic activity of the ventricles B) end-diastolic volume and end-systolic volume C) the pressure in the aorta and the lungs D) peripheral resistance and tension E) heart rate and venous return
E
Which of the following ion channels does not participate in the contractile cell action potential? 29) ______ A) type L calcium channels B) inward rectifying potassium channels C) delayed rectifying potassium channels D) voltage-gated sodium channels E) type T calcium channels
E
Which of the following is NOT a part of the excitation-contraction coupling in cardiac muscle? 30) ______ A) An action potential travels along transverse tubules. B) Calcium channels in the sarcoplasmic reticulum open, allowing calcium ions to enter the cytosol. C) Calcium channels in the plasma membrane open, allowing calcium ions to enter the cell. D) Calcium opens calcium channels in the sarcoplasmic reticulum. E) Calcium binds to calmodulin in the cytosol.
E
Which of the following variables is NOT an intrinsic factor that alters cardiac function? 68) ______ A) preload B) atrial pressure C) end-systolic volume D) Starling's law E) hormonal stimulation
E
Which statement best describes why atrial depolarization is usually not detected on a normal ECG? 35) ______ A) The electrodes cannot be placed high enough on the chest to detect the atria. B) The atria are so small and the depolarization happens so quickly that it cannot be detected. C) The atria do not contract only the AV valves open. D) The voltage change in the atria is minimal and therefore does not register on an ECG. E) It occurs at the same time as the QRS complex
E
