Question 1

An increase in cardiac sympathetic activity ____________________ the velocity of impulse conduction through the heart.

Accepted Answer

The answer of An increase in cardiac sympathetic activity ____________________...

Question 2

Stroke volume can vary by alterations in both intrinsic and extrinsic control mechanisms.

Accepted Answer

A) True 
 B)False

Question 3

Cardiac tetany never occurs under normal conditions for which of these reasons

Accepted Answer

A) because there are no distinct motor units in the heart 
B) because there is inadequate oxygen supply via the coronary circulation 
C) because of the long duration of cardiac muscle's refractory period preventing summation of contraction 
D) because the heart contracts with maximal force every beat, increasing the strength of the cardiac contraction

Question 4

What is the normal sequence of the spread of cardiac excitation

Accepted Answer

A) SA node, atria, AV node, bundle of His, Purkinje fibres, ventricular myocardium 
B) Atria, SA node, AV node, Purkinje fibres, bundle of His, ventricular myocardium 
C) SA node, atria, AV node, Purkinje fibres, bundle of His, ventricular myocardium 
D) AV node, SA node, Atria, Purkinje fibres, bundle of His, ventricular myocardium

Question 5

The rate of appearance of the QRS and T waves is unaffected if the heart develops a complete heart block.

Accepted Answer

A) True 
 B)False

Question 6

An increase in parasympathetic activity ____________________ the rate of depolarization of the SA node.

Accepted Answer

The answer of An increase in parasympathetic activity ____________________ the...

Question 7

On an electrocardiogram, what represents depolarization of the ventricles

Accepted Answer

A) P wave 
B) T wave 
C) S wave 
D) QRS complex

Question 8

Which structures join adjacent cardiac muscle cells end-to-end in the ventricles

Accepted Answer

A) intercalated discs 
B) sarcomeres 
C) Purkinje fibres 
D) sinoatrial nodes

Question 9

Which of the following actions produces the second heart sound

Accepted Answer

A) opening of the AV valves 
B) closing of the AV valves 
C) opening of the semilunar valves 
D) closing of the semilunar valves

Question 10

Match the term, labelled 
Match the term, labelled a. through g., with their correct characteristic.
-carries cholesterol to cells

Accepted Answer

A) gap junction 
B) HDL 
C) functional syncytium 
D) heart valve 
E) pericardial sac
F)LDL
G)adenosine

Question 11

____________________ carries cholesterol to cells, whereas ____________________ transports it away from cells.

Accepted Answer

The answer of ____________________ carries cholesterol to cells, whereas ____________________...

Question 12

When ECF K⁺ levels fall below normal, the heart becomes weak, flaccid, and dilated.

Accepted Answer

A) True 
 B)False

Question 13

Match the ions, labelled a. through c., with the events being described. (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

A) K⁺ 
B) Na+ 
C) Ca²⁺

Question 14

Match the EKG features, labelled a. through f., with their correct characteristic.
-time during which ventricles are filling

Accepted Answer

A) P wave 
B) QRS complex 
C) T wave 
D) PR interval 
E) TP interval
F)ST segment

Question 15

Compare and contrast intrinsic and extrinsic controls of cardiac activity.

Accepted Answer

The answer of Compare and contrast intrinsic and extrinsic controls...

Question 16

An increase in cardiac sympathetic activity ____________________ the contractility of the ventricles.

Accepted Answer

The answer of An increase in cardiac sympathetic activity ____________________...

Question 17

The right half of the heart pumps blood through the pulmonary circuit.Through which circuit does the left half pump blood

Accepted Answer

A) diastolic 
B) pulmonary 
C) systolic 
D) systemic

Question 18

The ESV of the heart averages about 140 mL.

Accepted Answer

A) True 
 B)False

Question 19

Match the term, labelled 
Match the term, labelled a. through g., with their correct characteristic.
-prevents backflow of blood

Accepted Answer

A) gap junction 
B) HDL 
C) functional syncytium 
D) heart valve 
E) pericardial sac
F)LDL
G)adenosine

Question 20

Match the effects with sympathetic or parasympathetic stimulation (or neither) of the heart. (Options may be used more than once or not at all.)
-decreases the contractility of the ventricular muscle

Accepted Answer

A) effect caused by sympathetic stimulation 
B) effect caused by parasympathetic stimulation 
C) not brought about by either sympathetic or parasympathetic stimulation

Exam 8: Cardiac Physiology

An increase in cardiac sympathetic activity ____________________ the velocity of impulse conduction through the heart.

Stroke volume can vary by alterations in both intrinsic and extrinsic control mechanisms.

Cardiac tetany never occurs under normal conditions for which of these reasons

What is the normal sequence of the spread of cardiac excitation

The rate of appearance of the QRS and T waves is unaffected if the heart develops a complete heart block.

An increase in parasympathetic activity ____________________ the rate of depolarization of the SA node.

On an electrocardiogram, what represents depolarization of the ventricles

Which structures join adjacent cardiac muscle cells end-to-end in the ventricles

Which of the following actions produces the second heart sound

Match the term, labelled Match the term, labelled a. through g., with their correct characteristic. -carries cholesterol to cells

carries cholesterol to cells, whereas transports it away from cells.

When ECF K⁺ levels fall below normal, the heart becomes weak, flaccid, and dilated.

Match the ions, labelled a. through c., with the events being described. (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.

Match the EKG features, labelled a. through f., with their correct characteristic. -time during which ventricles are filling

Compare and contrast intrinsic and extrinsic controls of cardiac activity.

An increase in cardiac sympathetic activity ____________________ the contractility of the ventricles.

The right half of the heart pumps blood through the pulmonary circuit.Through which circuit does the left half pump blood

The ESV of the heart averages about 140 mL.

Match the term, labelled Match the term, labelled a. through g., with their correct characteristic. -prevents backflow of blood

Match the effects with sympathetic or parasympathetic stimulation (or neither) of the heart. (Options may be used more than once or not at all.) -decreases the contractility of the ventricular muscle