Question 1

The middle layer of the heart wall that is made of cardiac muscle tissue is the ________.

Accepted Answer

The answer of The middle layer of the heart wall...

Question 2

The ________ cardiac vein travels alongside the right marginal artery.

Accepted Answer

The answer of The ________ cardiac vein travels alongside the...

Question 3

About 70% of the ventricle filling is achieved passively without the contraction of the atria.

Accepted Answer

During the cardiac cycle, about 70% of ventricular filling occurs passively when blood flows from the atria to the ventricles due to pressure differences, before atrial contraction (atrial systole) completes the remaining 30% of filling.

Question 4

Parasympathetic and sympathetic influence on heart rate is controlled by reflexes.

Accepted Answer

The autonomic nervous system regulates heart rate through reflexes, with the parasympathetic and sympathetic systems providing opposing influences.

Question 5

The connections shared by arteries that allow them to shunt blood from one artery to another are called ________.

Accepted Answer

The answer of The connections shared by arteries that allow...

Question 6

The numerous ________ within the intercalated discs prevent cardiac muscle fibers from pulling apart.

Accepted Answer

The answer of The numerous ________ within the intercalated discs...

Question 7

The inferior chambers of the heart are called ________.

Accepted Answer

The answer of The inferior chambers of the heart are...

Question 8

Though the autonomic innervation by autonomic centers in the brainstem cannot initiate a heartbeat, it can increase or decrease the heart rate.

Accepted Answer

The autonomic centers in the brainstem can modify the rate of the heartbeat by increasing or decreasing it, but they cannot initiate the beat. The rhythmic contractions of the heart are initiated by the sinoatrial node (SA node), the natural pacemaker of the heart.

Question 9

The term used to describe the inadequate blood flow to a structure caused by obstruction of the blood supply is ________.

Accepted Answer

The answer of The term used to describe the inadequate...

Question 10

Select all that occur during the plateau phase of an action potential on a cardiac muscle cell.
A) Calcium is entering the cell.
B) Potassium is exiting the cell.
C) Sodium is entering the cell.
D) Calcium is exiting the cell.

Accepted Answer

The answer of Select all that occur during the plateau...

Question 11

Normally, the left and right ventricles eject the same amount of blood.

Accepted Answer

The left and right ventricles are part of the heart's circulatory system and are designed to pump the same volume of blood to maintain a balanced circulation between the systemic and pulmonary circuits.

Question 12

The property that allows the heart to initiate each heartbeat itself is called ________.

Accepted Answer

The answer of The property that allows the heart to...

Question 13

________ innervation increases the rate and the force of heart contraction.

Accepted Answer

The answer of ________ innervation increases the rate and the...

Question 14

The heartbeat is initiated by the cells of the ________ node.

Accepted Answer

The answer of The heartbeat is initiated by the cells...

Question 15

The atrial reflex relies upon chemoreceptors to detect stretch in the atrial wall.

Accepted Answer

The atrial reflex, also known as the Bainbridge reflex, relies on baroreceptors, not chemoreceptors, to detect stretch in the atrial wall.

Question 16

Around day 21 of development the primitive heart begins to beat. At this stage it contains the four chambers: two atria and two ventricles.

Accepted Answer

At around day 21, the primitive heart begins to beat, but it does not yet have four chambers. The heart initially forms as a simple tube and later develops into a four-chambered structure.

Question 17

If the stroke volume is unequal between the left and right ventricles, ________ may occur, which is excess fluid surrounding or within cells.

Accepted Answer

The answer of If the stroke volume is unequal between...

Question 18

During ventricular contraction, the semilunar valves close in order to permit the blood to enter the large arterial trunks that carry blood away from the heart.

Accepted Answer

During ventricular contraction, the semilunar valves (aortic and pulmonary valves) open to allow blood to enter the large arterial trunks (aorta and pulmonary artery) that carry blood away from the heart; they close to prevent backflow of blood into the heart when the ventricles relax.

Question 19

Purkinje fibers are small fibers within the atria that conduct impulses rapidly.

Accepted Answer

Purkinje fibers are located in the ventricles, not the atria, and they conduct impulses rapidly to ensure coordinated contraction of the ventricles.

Question 20

The anterior part of each atrium is a flaplike extension called a(n) ________.

Accepted Answer

The answer of The anterior part of each atrium is...

Quiz 19: Cardiovascular System: Heart