Q: Which of the following equations correctly represents cardiac output?

$$\text{CO} = \text{HR} \times \text{SV}$$

Q: A patient has a heart rate of 90 beats/min and a stroke volume of 80 mL/beat. What is their cardiac output?

$$\text{CO} = 90 \times 80 = 7200\ \text{mL/min}$$

Q: Which of the following is the correct formula for mean arterial pressure (MAP)?

$$\text{MAP} = \text{CO} \times \text{TPR}$$

Question 1

Which of the following best describes the sequence of blood flow through the heart, starting from the vena cava?

Accepted Answer

Right atrium → Tricuspid valve → Right ventricle → Pulmonary semilunar valve → Pulmonary artery → Lungs → Pulmonary vein → Left atrium → Bicuspid (mitral) valve → Left ventricle → Aortic semilunar valve → Aorta

Question 2

During which phase of the cardiac cycle are the ventricles contracting and the AV valves closed?

Accepted Answer

Ventricular systole

Question 3

Which event on an ECG corresponds to ventricular depolarization?

Accepted Answer

QRS complex

Question 4

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

Accepted Answer

It prolongs depolarization, preventing tetanus and allowing time for ventricular filling and ejection.

Question 5

Which of the following equations correctly represents cardiac output?

Accepted Answer

$$	ext{CO} = 	ext{HR} 	imes 	ext{SV}$$

Question 6

A patient has a heart rate of 90 beats/min and a stroke volume of 80 mL/beat. What is their cardiac output?

Accepted Answer

$$	ext{CO} = 90 	imes 80 = 7200\ 	ext{mL/min}$$

Question 7

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

Accepted Answer

It must generate higher pressure to pump blood through the systemic circulation.

Question 8

Which of the following chemicals is most likely to cause vasodilation during exercise?

Accepted Answer

Nitric oxide (NO)

Question 9

If the baroreceptors in the carotid sinus detect an increase in blood pressure, what is the expected autonomic response?

Accepted Answer

Increased parasympathetic activity and decreased sympathetic activity

Question 10

Which of the following is true regarding the initiation of action potentials in cardiac autorhythmic (pacemaker) cells?

Accepted Answer

They spontaneously depolarize due to a slow influx of Na+ and Ca2+ until threshold is reached.

Question 11

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

Accepted Answer

Mitral (bicuspid) valve

Question 12

Which of the following best describes the effect of sympathetic stimulation on the heart?

Accepted Answer

Increases heart rate and contractility via $$\$$beta_1$$ adrenergic receptors

Question 13

Which of the following is the correct formula for mean arterial pressure (MAP)?

Accepted Answer

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

Question 14

A patient experiences a sudden drop in blood pressure. Which of the following compensatory mechanisms is most likely to occur first?

Accepted Answer

Increased heart rate via sympathetic activation

Question 15

Which of the following statements about the cardiac cycle is correct?

Accepted Answer

The 'lub' sound is caused by closure of the AV valves at the onset of ventricular systole.

Question 16

Which of the following best explains why tetanus cannot occur in cardiac muscle?

Accepted Answer

The long plateau phase of the action potential prevents rapid re-excitation.

Question 17

Which of the following would most likely cause an increase in total peripheral resistance (TPR)?

Accepted Answer

Vasoconstriction of arterioles

Question 18

Which of the following is a direct effect of increased parasympathetic stimulation on the heart?

Accepted Answer

Decreased rate of depolarization in SA node, leading to decreased heart rate

Question 19

Which of the following best describes the role of baroreceptors in blood pressure regulation?

Accepted Answer

They detect changes in arterial wall stretch and send signals to the medulla to adjust autonomic output.

Study Guide: The Cardiovascular System – The Heart and Blood Vessels

Study Guide - Practice Questions

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