Q: If a person’s inspiratory reserve volume (IRV) is 3000 mL, tidal volume (TV) is 500 mL, and expiratory reserve volume (ERV) is 1200 mL, what is their vital capacity (VC)?

$$VC = TV + IRV + ERV = 500 + 3000 + 1200 = 4700\ \text{mL}$$

Question 1

Which of the following best describes the role of surfactant in the lungs?

Accepted Answer

It decreases the surface tension in the alveoli, making them easier to inflate.

Question 2

A patient with emphysema has difficulty exhaling because:

Accepted Answer

Their lungs become overly compliant and cannot easily expel air.

Question 3

Which equation correctly represents the calculation for cardiac output (CO)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 4

During an acute asthma attack, which of the following changes occurs in the airways?

Accepted Answer

Bronchioles constrict and airway resistance increases.

Question 5

Which of the following best explains why increasing blood vessel length increases resistance to blood flow?

Accepted Answer

Longer vessels provide a larger surface area for friction between blood and vessel walls.

Question 6

If a person’s inspiratory reserve volume (IRV) is 3000 mL, tidal volume (TV) is 500 mL, and expiratory reserve volume (ERV) is 1200 mL, what is their vital capacity (VC)?

Accepted Answer

$$VC = TV + IRV + ERV = 500 + 3000 + 1200 = 4700\ 	ext{mL}$$

Question 7

Which of the following would most likely increase the forced expiratory volume (FEV1) in a patient with asthma?

Accepted Answer

Administering a bronchodilator to relax smooth muscle in the airways.

Question 8

Which of the following is the correct formula for total lung capacity (TLC)?

Accepted Answer

$$TLC = TV + IRV + ERV + RV$$

Question 9

A decrease in which of the following would most directly result in a decrease in cardiac output, assuming all other variables remain constant?

Accepted Answer

Stroke volume (SV)

Question 10

Which of the following best describes the effect of increased blood viscosity on blood flow?

Accepted Answer

Blood flow decreases due to increased resistance.

Question 11

During moderate aerobic exercise, which respiratory variable increases the most to meet the increased metabolic demand?

Accepted Answer

Tidal volume

Question 12

Which of the following is a direct consequence of pneumothorax?

Accepted Answer

Collapse of the lung (atelectasis)

Question 13

If the pressure gradient across a blood vessel increases while resistance remains constant, what happens to blood flow?

Accepted Answer

Blood flow increases.

Question 14

Which of the following best explains why the heart rate must increase if stroke volume decreases, in order to maintain cardiac output?

Accepted Answer

Because cardiac output is the product of heart rate and stroke volume.

Question 15

Which of the following is the best definition of afterload?

Accepted Answer

The pressure that must be overcome to open the aortic and pulmonary semilunar valves.

Question 16

A patient has a heart rate (HR) of 80 beats/min and a stroke volume (SV) of 70 mL/beat. What is their cardiac output (CO)?

Accepted Answer

$$CO = HR 	imes SV = 80 	imes 70 = 5600\ 	ext{mL/min}$$

Question 17

Which of the following would most likely occur if the intrapleural pressure becomes equal to atmospheric pressure?

Accepted Answer

The lungs would collapse due to loss of the partial vacuum.

Question 18

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The greater the end diastolic volume, the greater the force of contraction.

Question 19

Which of the following is a likely compensation mechanism for aortic valve stenosis?

Accepted Answer

Increasing contractility to increase stroke volume.

Question 20

Which of the following would most likely decrease the rate of blood flow through a vessel, assuming all other factors remain constant?

Accepted Answer

Decreasing the vessel radius.

Respiratory and Cardiovascular Physiology: Ventilation, Blood Flow, and Cardiac Function

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