Q: Which equation correctly represents the calculation of minute ventilation (MV)?

$$MV = \text{tidal volume} \times \text{respiratory rate}$$

Q: A patient has the following lung volumes: tidal volume (TV) = 500 mL, inspiratory reserve volume (IRV) = 3000 mL, expiratory reserve volume (ERV) = 1100 mL, and residual volume (RV) = 1200 mL. What is their vital capacity (VC)?

$$VC = TV + IRV + ERV = 500 + 3000 + 1100 = 4600\ \text{mL}$$

Question 1

During inhalation, which physiological change occurs in the thoracic cavity to allow air to flow into the lungs?

Accepted Answer

The volume of the thoracic cavity increases, decreasing intrapulmonary pressure below atmospheric pressure.

Question 2

Which muscle is considered the primary muscle of inspiration during quiet breathing?

Accepted Answer

Diaphragm

Question 3

A patient suffers a puncture wound to the chest wall, resulting in a collapsed lung. What is the most likely physiological explanation for this event?

Accepted Answer

The attraction between the pleural membranes was disrupted, causing pneumothorax and lung collapse.

Question 4

Which of the following best describes the role of accessory inspiratory muscles during respiration?

Accepted Answer

They are recruited during increased respiratory demand to increase rib movement and accommodate O$$_2$$ need.

Question 5

Which equation correctly represents the calculation of minute ventilation (MV)?

Accepted Answer

$$MV = 	ext{tidal volume} 	imes 	ext{respiratory rate}$$

Question 6

If a person has a tidal volume of 500 mL and a respiratory rate of 12 breaths per minute, what is their minute ventilation?

Accepted Answer

$$6000\ 	ext{mL/min}$$

Question 7

Which of the following is NOT a function of the pleural membrane?

Accepted Answer

It actively contracts to expand the lungs during inhalation.

Question 8

Which respiratory volume cannot be measured in a healthy person and represents the air remaining in the lungs even after collapse?

Accepted Answer

Minimal volume

Question 9

A patient has the following lung volumes: tidal volume (TV) = 500 mL, inspiratory reserve volume (IRV) = 3000 mL, expiratory reserve volume (ERV) = 1100 mL, and residual volume (RV) = 1200 mL. What is their vital capacity (VC)?

Accepted Answer

$$VC = TV + IRV + ERV = 500 + 3000 + 1100 = 4600\ 	ext{mL}$$

Question 10

Which law states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each individual gas?

Accepted Answer

Dalton's Law

Question 11

According to Henry's Law, what determines the amount of a gas that dissolves in a liquid at a given temperature?

Accepted Answer

The partial pressure of the gas and its solubility

Question 12

Which of the following best explains why carbon monoxide (CO) poisoning is so dangerous?

Accepted Answer

CO irreversibly binds to the heme group, preventing oxygen transport.

Question 13

Which of the following is the correct formula for calculating inspiratory capacity (IC)?

Accepted Answer

$$IC = TV + IRV$$

Question 14

Which respiratory volume represents the amount of air remaining in the lungs after maximal exhalation and is necessary to prevent lung collapse?

Accepted Answer

Residual volume (RV)

Question 15

A person is exercising vigorously. Which muscles are likely to be recruited to assist with forced exhalation?

Accepted Answer

Internal intercostal muscles and rectus abdominis

Question 16

Which of the following statements about dead space is correct?

Accepted Answer

Dead space air is the volume that remains in the trachea and airways and does not participate in gas exchange.

Question 17

Which of the following is a direct result of the Hering-Breuer (inflation) reflex?

Accepted Answer

Prevents over-inflation of the lungs by inhibiting inspiratory neurons.

Question 18

Which chemical is most closely monitored by central chemoreceptors in the brain to regulate breathing rate?

Accepted Answer

CO$$_2$$

Question 19

Which of the following equations correctly represents the conversion of carbon dioxide to bicarbonate in the blood?

Accepted Answer

$$CO_2 + H_2O$$ \rightarrow H_2CO_3 \rightarrow H^+ + $$HCO_3$$^-$$

Respiratory System: Mechanics, Muscles, Membranes, and Volumes

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