[02] Mechanics of Breathing

Question 1

What are the two main processes involved in the mechanics of breathing?

Answer 1

• Inhalation (Inspiration)
• Exhalation (Expiration)

Question 2

What happens during inhalation?

Answer 2

The diaphragm contracts, chest cavity expands, air pressure within the lungs decreases, and air flows into the lungs

Question 3

What happens during exhalation?

Answer 3

The diaphragm relaxes, chest cavity decreases in size, air pressure within the lungs increases, and air is expelled

Question 4

What is the role of the diaphragm in the mechanics of breathing?

Answer 4

It contracts and relaxes to cause changes in the chest cavity size and air pressure, which drives the flow of air in and out of the lungs

Question 5

What is tidal volume (TV)?

Answer 5

The amount of air that is inhaled or exhaled during a normal breath

Question 6

What is inspiratory reserve volume (IRV)?

Answer 6

The maximum amount of air that can be inhaled after a normal inhalation

Question 7

What is expiratory reserve volume (ERV)?

Answer 7

The maximum amount of air that can be exhaled after a normal exhalation

Question 8

What is residual volume (RV)?

Answer 8

The amount of air remaining in the lungs after a maximal exhalation

Question 9

What is vital capacity (VC)?

Answer 9

The total amount of air that can be exhaled after a maximum inhalation

Question 10

What is the role of the intercostal muscles in the mechanics of breathing?

Answer 10

They contract and expand to assist in changing the size of the chest cavity during breathing

Question 11

What is the role of pleural pressure in the mechanics of breathing?

Answer 11

It helps to keep the lungs inflated and aids in the expansion and contraction of the lungs during breathing

Question 12

What factors can influence the mechanics of breathing?

Answer 12

• Lung compliance
• Airway resistance
• Lung volumes and capacities
• Gas pressure differences

Question 13

What is lung compliance?

Answer 13

The measure of the lung’s ability to stretch and expand

Question 14

How does airway resistance affect the mechanics of breathing?

Answer 14

Higher resistance can make it harder to breathe, as more force is needed to move air through the airways

Question 15

How do gas pressure differences affect the mechanics of breathing?

Answer 15

Differences in gas pressure drive the flow of air in and out of the lungs. Air moves from areas of high pressure to low pressure

Question 16

What is the function of surfactant in the mechanics of breathing?

Answer 16

It reduces surface tension within the alveoli, preventing them from collapsing and aiding in lung expansion

Question 17

What is minute ventilation?

Answer 17

The total volume of air inhaled or exhaled per minute

Question 18

What is alveolar ventilation?

Answer 18

The volume of air that reaches the alveoli and participates in gas exchange per minute

Question 19

How does lung elasticity affect the mechanics of breathing?

Answer 19

It contributes to lung’s ability to return to its resting state after inhalation and affects the ease of lung inflation