Question 1

Which of the following best describes atmospheric pressure ($$P_{atm}) at $$sea level?

Accepted Answer

The pressure exerted by the air surrounding the body, equal to 760 mm Hg

Question 2

If a person ascends to a high elevation, what happens to atmospheric pressure ($$P_{atm}) $$and why does this matter for pulmonary ventilation?

Accepted Answer

$$P_{atm}$$ decreases, reducing the pressure gradient for air to flow into the lungs

Question 3

Which statement about intrapulmonary (intra-alveolar) pressure ($$P_{pul}) is $$correct?

Accepted Answer

$$P_{pul}$$ fluctuates with breathing and eventually equalizes with $$P_{atm}$$

Question 4

During normal quiet inspiration, which of the following occurs?

Accepted Answer

Thoracic volume increases and $$P_{pul}$$ drops below $$P_{atm}$$

Question 5

What is the primary reason intrapleural pressure ($$P_{ip}) is $$always negative relative to both $$P_{atm}$$ and $$P_{pul}$$?

Accepted Answer

The inward recoil of the lungs and surface tension oppose the outward pull of the chest wall, creating a slight vacuum

Question 6

If intrapleural pressure ($$P_{ip}) $$becomes equal to atmospheric pressure ($$P_{atm}$$), what is the likely consequence?

Accepted Answer

The lungs will collapse due to loss of the pressure gradient

Question 7

Which of the following best explains why a puncture wound to the chest can cause lung collapse (atelectasis)?

Accepted Answer

It allows air to enter the pleural cavity, equalizing $$P_{ip}$$ with $$P_{atm}$$

Question 8

Which of the following forces opposes lung collapse and helps keep the lungs inflated?

Accepted Answer

Elasticity of the chest wall pulling the thorax outward

Question 9

A patient with a chest injury has air in the pleural cavity. What is the medical term for this condition, and what is the immediate effect on lung function?

Accepted Answer

Pneumothorax; loss of negative $$P_{ip}$$ and lung collapse

Question 10

Which of the following best describes the relationship between pressure and volume during inspiration, according to Boyle's Law?

Accepted Answer

As thoracic volume increases, intrapulmonary pressure decreases

Question 11

During expiration, which of the following changes occurs in the thoracic cavity and pressures?

Accepted Answer

Thoracic volume decreases and $$P_{pul}$$ increases above $$P_{atm}$$

Question 12

Which of the following scenarios would most likely result in a positive respiratory pressure?

Accepted Answer

Intrapulmonary pressure is greater than atmospheric pressure

Question 13

A climber at high altitude is experiencing difficulty breathing. Which pressure change is primarily responsible for this?

Accepted Answer

Decreased $$P_{atm}$$

Question 14

Which of the following best explains why the lungs do not normally collapse between breaths?

Accepted Answer

Intrapleural pressure is always negative, creating a pressure gradient that keeps the lungs expanded

Question 15

If a patient has a disease that increases the surface tension of alveolar fluid, what is the most likely effect on intrapleural pressure and lung function?

Accepted Answer

Intrapleural pressure becomes less negative, increasing the risk of lung collapse

Pulmonary Ventilation and Pressure Relationships in the Thoracic Cavity

Guida di studio - Domande di pratica

Study guide - Flashcard