Question 1

Which law explains why air moves into the lungs during inspiration when the thoracic cavity volume increases?

Accepted Answer

Boyle's Law

Question 2

During normal quiet expiration, which of the following events occurs?

Accepted Answer

Elastic lungs recoil and intrapulmonic pressure increases

Question 3

A patient with chronic respiratory disease relies primarily on which regulatory mechanism to stimulate breathing?

Accepted Answer

Peripheral chemoreceptors responding to decreased PaO$$_2$$

Question 4

According to Dalton’s Law, what is the partial pressure of oxygen in atmospheric air at sea level ($$P_{atm} = 760 mm Hg$$, $$O_2 = 21$$%)?

Accepted Answer

$$P_{O_2$} = 160 mm Hg$$

Question 5

Which of the following factors will increase the release of oxygen from hemoglobin in peripheral tissues?

Accepted Answer

Increased 2,3-biphosphoglycerate (BPG)

Question 6

A patient is hyperventilating. What effect does this have on blood CO$$_2$$ levels and pH?

Accepted Answer

CO$$_2$$ decreases, pH increases

Question 7

Which structure is responsible for preventing over-expansion of the lungs during inspiration?

Accepted Answer

Hering-Breuer reflex

Question 8

Which of the following best describes the role of the visceral pleura?

Accepted Answer

Covers the external lung surface including the fissures

Question 9

During forced expiration, which muscles are primarily involved?

Accepted Answer

Internal intercostals and abdominal muscles

Question 10

Which of the following is the correct formula for calculating Functional Residual Capacity (FRC)?

Accepted Answer

$$FRC = ERV + RV$$

Question 11

A patient with anemia is most likely to experience which type of hypoxia?

Accepted Answer

Hypemic hypoxia

Question 12

Which of the following statements about oxygen transport is correct?

Accepted Answer

Only dissolved oxygen can diffuse into tissues

Question 13

Which of the following mechanisms accounts for the majority of carbon dioxide transport in the blood?

Accepted Answer

As bicarbonate ions

Question 14

If the partial pressure of oxygen in the alveoli is 100 mm Hg and in the capillary blood is 40 mm Hg, in which direction will oxygen diffuse?

Accepted Answer

From alveoli into capillary blood

Question 15

Which of the following will decrease oxygen concentration in the blood?

Accepted Answer

Decreased diffusion across the pulmonary membrane

Question 16

Which respiratory control center is primarily responsible for initiating inspiration?

Accepted Answer

Dorsal respiratory group (DRG) in the medulla

Question 17

According to Henry’s Law, the amount of gas dissolved in a liquid is proportional to which factors?

Accepted Answer

Partial pressure and solubility coefficient

Question 18

Which of the following best describes the Bohr effect?

Accepted Answer

Decreased pH reduces oxygen affinity for hemoglobin

Question 19

A patient with a collapsed portion of alveoli is most likely experiencing which physiological problem?

Accepted Answer

Ventilation/perfusion mismatch

Question 20

Which of the following is a correct sequence for the process of respiration?

Accepted Answer

Ventilation → Diffusion → Perfusion

Physiology of the Respiratory System: Mechanics, Gas Exchange, and Regulation

Study Guide - Practice Questions