$$SV = EDV - ESV = 120\,\text{mL} - 50\,\text{mL} = 70\,\text{mL}$$

$$CO = SV \times HR = 65\,\text{mL} \times 80 = 5200\,\text{mL/min}$$

Question 1

Which of the following correctly describes the function of the pericardium in the heart?

Accepted Answer

It prevents overstretching of the heart and reduces friction during heartbeats.

Question 2

During the cardiac cycle, which event occurs immediately after ventricular filling?

Accepted Answer

Isovolumetric contraction

Question 3

Which equation correctly represents cardiac output ($$CO) in $$terms of stroke volume ($$SV) $$and heart rate ($$HR$$)?

Accepted Answer

$$CO = SV 	imes HR$$

Question 4

A patient has an end diastolic volume ($$EDV) of 120 mL $$and an end systolic volume ($$ESV) of 50 mL. $$What is their stroke volume ($$SV$$)?

Accepted Answer

$$SV = EDV - ESV = 120\,	ext{mL} - 50\,	ext{mL} = 70\,	ext{mL}$$

Question 5

Which heart valve prevents backflow of blood from the left ventricle to the left atrium?

Accepted Answer

Mitral (bicuspid) valve

Question 6

Which of the following best explains the plateau phase in the action potential of cardiac contractile cells?

Accepted Answer

It is caused by the influx of $$Ca^{2+}$$ ions through slow channels, balancing $$K^+$$ efflux.

Question 7

Which component of the intrinsic conduction system is responsible for the 0.1 second delay, and why is this delay important?

Accepted Answer

Atrioventricular (AV) node; it allows the atria to finish contracting before the ventricles contract.

Question 8

Which abnormality in an ECG tracing is characterized by rapid, irregular electrical activity and loss of coordinated contraction?

Accepted Answer

Fibrillation

Question 9

During ventricular ejection, which valves are open and which are closed?

Accepted Answer

Semilunar valves are open; AV valves are closed.

Question 10

Which layer of a blood vessel is primarily responsible for vasoconstriction and vasodilation?

Accepted Answer

Tunica media

Question 11

Which type of artery is known as a pressure reservoir and can be found in the aorta?

Accepted Answer

Elastic artery

Question 12

Which capillary type is most likely to be found in the liver and allows passage of large molecules and cells?

Accepted Answer

Sinusoidal capillary

Question 13

Which equation correctly describes the relationship between blood flow ($$F$$), blood pressure ($$\Delta P$$), and resistance ($$R$$)?

Accepted Answer

$$F = \frac{\Delta P}{R}$$

Question 14

Which factor is the most significant influence on peripheral resistance in the circulatory system?

Accepted Answer

Blood vessel diameter

Question 15

Where in the circulatory system is the steepest drop in blood pressure observed?

Accepted Answer

Arterioles

Question 16

Which mechanism assists venous return by increasing pressure in the veins during inhalation?

Accepted Answer

Respiratory pump

Question 17

Which vessel type has the highest relative cross-sectional area, resulting in the slowest velocity of blood flow?

Accepted Answer

Capillaries

Question 18

At which end of the capillary is filtration predominant, and what pressure drives this process?

Accepted Answer

Arterial end; hydrostatic pressure

Question 19

A patient with a heart rate of 80 beats per minute and a stroke volume of 65 mL has a cardiac output of:

Accepted Answer

$$CO = SV 	imes HR = 65\,	ext{mL} 	imes 80 = 5200\,	ext{mL/min}$$

Question 20

Which of the following best describes the effect of vagal tone on heart rate?

Accepted Answer

It decreases heart rate by increasing parasympathetic activity.

The Cardiovascular System: Heart and Blood Vessels – Study Guide

Study Guide - Practice Questions