CO = HR \times SV = 5400 ml/min; $$CO = HR \times SV$$

$$MAP = \text{diastolic pressure} + \frac{1}{3} \text{pulse pressure}$$

Question 1

Which structure acts as the primary pacemaker of the heart, and why does it have this role?

Accepted Answer

Sinoatrial (SA) node, because it produces action potentials faster than other areas.

Question 2

During the cardiac cycle, what is the duration of ventricular systole if the heart rate is 75 beats per minute?

Accepted Answer

0.3 seconds

Question 3

If the End Diastolic Volume (EDV) is 120 ml and the End Systolic Volume (ESV) is 50 ml, what is the stroke volume (SV)? Provide the formula used.

Accepted Answer

SV = EDV - ESV = 70 ml; $$SV = EDV - ESV$$

Question 4

Which event is responsible for the first heart sound (LUB) during the cardiac cycle?

Accepted Answer

Closure of the AV valves due to higher pressure in ventricles than atria

Question 5

A patient has a heart rate (HR) of 90 beats/min and a stroke volume (SV) of 60 ml/beat. What is their cardiac output (CO)? Provide the formula.

Accepted Answer

CO = HR 	imes SV = 5400 ml/min; $$CO = HR 	imes SV$$

Question 6

Which of the following would most likely cause bradycardia?

Accepted Answer

Increased parasympathetic nervous system activity

Question 7

What is the effect of increased venous return on stroke volume, according to Frank-Starling’s Law?

Accepted Answer

Increased force of contraction and increased stroke volume

Question 8

Which formula correctly represents the relationship between blood flow, pressure gradient, and resistance?

Accepted Answer

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

Question 9

A patient with high blood pressure is at risk for edema. Which pressure change most directly contributes to this condition?

Accepted Answer

Increased blood hydrostatic pressure (BHP)

Question 10

Which hormone increases mean arterial pressure (MAP) by causing vasoconstriction and increasing blood volume?

Accepted Answer

Angiotensin II

Question 11

During capillary exchange, which process is primarily responsible for the movement of oxygen and carbon dioxide?

Accepted Answer

Diffusion

Question 12

Which of the following is a consequence of third-degree heart block?

Accepted Answer

Atria contract at SA node rate, ventricles at Purkinje fiber rate

Question 13

Which equation is used to calculate mean arterial pressure (MAP) given systolic and diastolic pressures?

Accepted Answer

$$MAP = 	ext{diastolic pressure} + \frac{1}{3} 	ext{pulse pressure}$$

Question 14

Which of the following would most likely decrease cardiac output (CO)?

Accepted Answer

Increased parasympathetic nervous system activity

Question 15

Which stage of hemostasis involves the conversion of fibrinogen to fibrin, and what factors are required?

Accepted Answer

Clot formation; requires thrombin and Ca$$^{2+}$$

Question 16

Which enzyme is responsible for breaking down fibrin during fibrinolysis?

Accepted Answer

Plasmin

Question 17

A patient with malnutrition is at risk for edema. Which pressure is most likely decreased in this scenario?

Accepted Answer

Blood osmotic pressure (BOP)

Question 18

Which of the following best describes the effect of sympathetic nervous system (SNS) stimulation on the heart?

Accepted Answer

Increases heart rate and force of contraction

Question 19

Which pathway is responsible for the conversion of angiotensinogen to angiotensin II?

Accepted Answer

Renin converts angiotensinogen to angiotensin I, then ACE converts angiotensin I to angiotensin II

Question 20

Which of the following is NOT a function of plasma proteins?

Accepted Answer

Transporting oxygen on iron of heme

Cardiovascular Physiology: Structure, Function, and Regulation

Study Guide - Practice Questions