Question 1

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all):
-valve does not close completely

Accepted Answer

Valvular insufficiency means the valve does not close completely, allowing blood to flow backwards through the valve.

Question 2

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all):
-decreases the rate of depolarization to threshold of the SA node

Accepted Answer

This effect is caused by parasympathetic stimulation, which releases acetylcholine and slows down the depolarization of the SA node.

Answer: A 
 This effect is caused by sympathetic stimulation, which releases norepinephrine and increases the rate of depolarization to threshold of the SA node.

Answer: C 
 This effect is not brought about by either sympathetic or parasympathetic stimulation.

Question 3

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all):
-valve does not open completely

Accepted Answer

Valvular stenosis is described as the valve not opening completely, leading to a narrowing of the valve opening and obstruction of blood flow. Valvular insufficiency is described as the valve not closing completely, allowing blood to leak back into the chamber it just left.

Question 4

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-the only point of electrical contact between the atria and ventricles

Accepted Answer

The AV node is the only point of electrical contact between the atria and ventricles, as it is the only structure that physically connects the two chambers. The SA node initiates the electrical activity, the bundle of His and Purkinje system rapidly transmits the electrical impulse to the ventricles, and gap junctions allow for the spread of electrical activity between adjacent cardiac cells.

Question 5

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-Inactivation of _____ channels brings about the slow drift of membrane potential to threshold in the cardiac autorhythmic cells.

Accepted Answer

The answer of Indicate which ion is involved in each...

Question 6

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-Explosive increase in membrane permeability to _____ brings about the rapidly rising phase of the action potential in contractile cardiac cells.

Accepted Answer

The explosive increase in membrane permeability to Na+ brings about the rapidly rising phase of the action potential in contractile cardiac cells.

Question 7

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-has the fastest rate of pacemaker activity

Accepted Answer

The factor with the fastest rate of pacemaker activity is the SA (sinoatrial) node, which is located in the right atrium and initiates cardiac excitation.

Question 8

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all):
-increases the contractility of the atrial and ventricular muscle

Accepted Answer

Sympathetic stimulation increases the contractility of the atrial and ventricular muscle.

Answer: B
 Parasympathetic stimulation does not increase the contractility of the heart.

Answer: C
 This effect is not brought about by either sympathetic or parasympathetic stimulation.

Question 9

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-Slow inward diffusion of _____ is largely responsible for the plateau portion of the cardiac action potential.

Accepted Answer

The plateau phase of the cardiac action potential is largely due to the slow inward diffusion of calcium ions.

Question 10

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-allows the impulse to spread from cell to cell

Accepted Answer

Gap junctions allow the electrical impulse generated by the SA node to spread from cell to cell in the heart muscle. The AV node serves to delay this impulse slightly to allow for appropriate coordination of ventricular contraction. The bundle of His and Purkinje system are specialized conducting fibers that rapidly carry the impulse through the ventricles of the heart.

Question 11

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-delays conduction of the impulse

Accepted Answer

The AV node is responsible for delaying the conduction of the impulse, allowing the atria time to contract and fill the ventricles with blood before the ventricles contract.

Question 12

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all):
-produces a "gurgling" murmur

Accepted Answer

A "gurgling" murmur is typically associated with valvular insufficiency (also known as regurgitation), where the valve fails to close properly and blood flows backward through the valve. Valvular stenosis, on the other hand, refers to a narrowing of the valve opening, which can produce a different type of murmur.

Question 13

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-Parasympathetic stimulation increases the permeability of the SA node to _____,whereas sympathetic stimulation decreases the permeability to this same ion.

Accepted Answer

The answer of Indicate which ion is involved in each...

Question 14

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-Changes in cytosolic _____ concentration bring about changes in the strength of cardiac contraction.

Accepted Answer

Changes in cytosolic calcium concentration are known to regulate the strength of cardiac contraction.

Question 15

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all):
-The rapid falling phase of the cardiac action potential is brought about primarily by the outward diffusion of _____.

Accepted Answer

The answer of Indicate which ion is involved in each...

Question 16

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all):
-increases the AV nodal delay

Accepted Answer

The parasympathetic nervous system, through the action of the vagus nerve, can increase the AV nodal delay, effectively slowing the heart rate by increasing the time it takes for electrical impulses to pass from the atria to the ventricles.

Question 17

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-rapidly conducts the impulse down the ventricular septum and throughout much of the ventricular musculature

Accepted Answer

The bundle of His and Purkinje system rapidly conduct the impulse down the ventricular septum and throughout much of the ventricular musculature. This allows for coordinated and synchronized contraction of the ventricular muscle. Gap junctions play a role in the spread of cardiac excitation but do not initiate it. The SA node initiates cardiac excitation, while the AV node delays it before it is transmitted to the ventricles.

Question 18

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all):
-produces a "whistling" murmur

Accepted Answer

A "whistling" murmur is typically associated with valvular stenosis, as it is indicative of a narrowed valve causing turbulence in the blood flow. Valvular insufficiency, on the other hand, typically produces a "whooshing" or "swishing" sound.

Question 19

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all):
-decreases the contractility of the ventricular muscle

Accepted Answer

The answer of Indicate the effects of sympathetic and parasympathetic...

Question 20

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all):
-the normal pacemaker of the heart

Accepted Answer

The SA node, or sinoatrial node, is recognized as the normal pacemaker of the heart because it initiates the electrical impulses that set the pace for cardiac activity.

Quiz 7: Cardiac Physiology

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all) : -valve does not close completely

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all) : -decreases the rate of depolarization to threshold of the SA node

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all) : -valve does not open completely

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -the only point of electrical contact between the atria and ventricles

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -Inactivation of _____ channels brings about the slow drift of membrane potential to threshold in the cardiac autorhythmic cells.

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -Explosive increase in membrane permeability to _____ brings about the rapidly rising phase of the action potential in contractile cardiac cells.

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -has the fastest rate of pacemaker activity

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all) : -increases the contractility of the atrial and ventricular muscle

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -Slow inward diffusion of _____ is largely responsible for the plateau portion of the cardiac action potential.

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -allows the impulse to spread from cell to cell

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -delays conduction of the impulse

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all) : -produces a "gurgling" murmur

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -Parasympathetic stimulation increases the permeability of the SA node to _____,whereas sympathetic stimulation decreases the permeability to this same ion.

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -Changes in cytosolic _____ concentration bring about changes in the strength of cardiac contraction.

Indicate which ion is involved in each event being described by using the answer code (options may be used more than once or not at all) : -The rapid falling phase of the cardiac action potential is brought about primarily by the outward diffusion of _____.

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all) : -increases the AV nodal delay

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -rapidly conducts the impulse down the ventricular septum and throughout much of the ventricular musculature

Indicate which valve abnormality is being described by using the answer code (options may be used more than once or not at all) : -produces a "whistling" murmur

Indicate the effects of sympathetic and parasympathetic stimulation on the heart by using the answer code (options may be used more than once or not at all) : -decreases the contractility of the ventricular muscle

Indicate which factor involved in the initiation and spread of cardiac excitation is being identified by using the answer code (options may be used more than once or not at all) : -the normal pacemaker of the heart