Unit 5 - A and P Module - Respiratory System Structure and Airflow Physics

Question 1

The direction and magnitude of air flow during breathing is determined by changes in __________ pressure.

Answer 1

alveolar

Question 2

Pulmonary surfactant is the fluid responsible for coming between the water molecules in the alveoli to reduce surface tension. By reducing surface tension within the alveoli, the compliance of the lung increases, which makes it easier to expand the lungs during an inspiratory cycle.

Answer 2

Additionally, reducing surface tension within the alveoli reduces the collapsing pressure, which will prevent the smaller alveoli from collapsing into larger ones.

Question 3

Put the events of inspiration in the correct order:

a. Pip decreases
b. Transpulmonary pressure increases
c. Diaphragm and intercostals contract
d. Palv decreases to less than Patm

(Pip = intrapleural pressure; Palv = intra-alveolar pressure; Patm = atmospheric pressure)

Answer 3

c, a, b, d

Question 4

Type I alveolar cells __________.

Answer 4

are simple squamous epithelial cells adapted for exchange

Question 5

Which of the following statements is not correct?

1. The radius of an individual bronchiole is low, but the overall cross-sectional area of all the bronchioles is quite high.
2. Airway resistance during inspiration increases.
3. In healthy lungs, the overall resistance in the conducting zone is high.
4. During quiet breathing, the difference between Palv and Patm is less than 2 mmHg.

Answer 5

Airway resistance during inspiration increases.

Question 6

Which of the following structures can allow gas exchange?

Answer 6

Alveoli

Question 7

Where does the most airway resistance in our respiratory system occur?

Answer 7

The trachea and bronchi

Question 8

Airway resistance is decreased by __________.

Answer 8

epinephrine and elevated carbon dioxide

Question 9

The pleural fluid surrounding each lung __________.

Answer 9

helps the lungs adhere to the thoracic cage

Question 10

Which of the following is the lowest pressure at rest following a quiet expiration?

Answer 10

Intrapleural

Question 11

The cells and structures that defend against bacteria and foreign particles entering the lungs include the __________.

Answer 11

mucus escalator, goblet cells, and macrophages

Question 12

Arrange these airways in the order that a breath of inhaled air would encounter them:

a. Larynx
b. Trachea
c. Pharynx
d. Bronchioles
e. Bronchi

Answer 12

c, a, b, e, d

Question 13

Which of the following statements is false?

1. The primary muscles involved in quiet breathing are the diaphragm, the external intercostals, and the scalenes.
2. The conducting portions of the airways filter out foreign materials via the mucus escalator.
3. The primary muscles involved in passive expiration are the internal intercostals and the abdominal muscles.
4. The upper airways and the bronchi warm air to body temperature.

Answer 13

The primary muscles involved in passive expiration are the internal intercostals and the abdominal muscles.

Question 14

According to Boyle’s law, __________.

Answer 14

the volume of a container of gas and the pressure of the gas within are inversely related