$$\text{Cardiac Output} = \text{Stroke Volume} \times \text{Heart Rate}$$

Question 1

Which of the following best describes the function of the chordae tendineae and papillary muscles during ventricular systole?

Accepted Answer

They contract to prevent the AV valves from prolapsing into the atria.

Question 2

During the cardiac cycle, which event directly causes the 'lub' sound heard during auscultation?

Accepted Answer

Closure of the AV (atrioventricular) valves

Question 3

Which of the following correctly traces the pathway of electrical depolarization through the heart’s intrinsic conduction system?

Accepted Answer

SA node → AV node → Bundle of His → Purkinje fibers

Question 4

Which phase of the cardiac cycle is characterized by ventricular filling and open AV valves?

Accepted Answer

Ventricular diastole

Question 5

What is the significance of the plateau phase in the action potential of a cardiac contractile cell?

Accepted Answer

It prolongs depolarization, ensuring sufficient time for ventricular ejection.

Question 6

Which equation correctly represents cardiac output?

Accepted Answer

$$	ext{Cardiac Output} = 	ext{Stroke Volume} 	imes 	ext{Heart Rate}$$

Question 7

Which of the following chemicals is most likely to cause vasodilation in arterioles?

Accepted Answer

Histamine

Question 8

A patient’s ECG shows an abnormal QRS complex. Which of the following is most likely affected?

Accepted Answer

Ventricular depolarization

Question 9

If the left ventricle fails to contract properly, which of the following will most likely occur?

Accepted Answer

Blood will accumulate in the pulmonary veins.

Question 10

Which of the following best explains the effect of increased sympathetic stimulation on the heart?

Accepted Answer

Increases heart rate and contractility

Question 11

Which of the following is the main driving force for blood flow in the systemic circulation?

Accepted Answer

Mean arterial pressure (MAP)

Question 12

During exercise, which of the following changes is most likely to occur in the cardiovascular system?

Accepted Answer

Increase in stroke volume and heart rate

Question 13

Which of the following statements about the baroreceptor reflex is correct?

Accepted Answer

It decreases sympathetic activity when blood pressure rises.

Question 14

Which of the following best describes the effect of acetylcholine (ACh) on pacemaker cells in the heart?

Accepted Answer

It decreases the rate of depolarization, slowing heart rate.

Question 15

Which of the following is true regarding the opening and closing of heart valves?

Accepted Answer

Semilunar valves open when ventricular pressure exceeds pressure in the arteries.

Question 16

Which of the following equations correctly represents mean arterial pressure (MAP)?

Accepted Answer

$$	ext{MAP} = 	ext{CO} 	imes 	ext{TPR}$$

Question 17

Which of the following is a direct effect of increased norepinephrine release on arterioles?

Accepted Answer

Vasoconstriction and increased resistance

Question 18

Which of the following best describes the effect of the plateau phase on the refractory period in cardiac contractile cells?

Accepted Answer

It lengthens the refractory period, preventing tetanus.

Question 19

Which of the following is most likely to occur if the baroreceptors in the carotid sinus are damaged?

Accepted Answer

The body will be unable to detect changes in blood pressure, impairing homeostasis.

Question 20

Which of the following best explains why the left ventricle wall is thicker than the right ventricle wall?

Accepted Answer

It pumps blood to the entire body, requiring greater pressure.

The Cardiovascular System: The Heart and Blood Vessels

Study Guide - Practice Questions