Question

question 20
1 pts
all of the following are true regarding the structure of surfactant except:
surface - active complex of phospholipids and proteins
produced in the main stem bronchus
keeps the lung inflated at the end of respiration
formed by type ii alveolar cells
question 21
1 pts
which of the following is true of the intrinsic muscles of the larynx?
their origin is the hyoid bone.
they move the larynx as a whole.
they serve in voice production.
both a and b are correct.
question 22
1 pts
which of the following is not part of the respiratory membrane?
ciliated respiratory mucosa
alveolar epithelium
capillary epithelium
all of the above are part of the respiratory membrane.

Explanation:

• Question 20: Surfactant is a surface - active complex of phospholipids and proteins formed by type II alveolar cells. It keeps the lung inflated at the end of respiration. It is not produced in the main stem bronchus.
• Question 21: The intrinsic muscles of the larynx serve in voice production. Muscles with origin in the hyoid bone and those that move the larynx as a whole are extrinsic laryngeal muscles.
• Question 22: The respiratory membrane consists of the alveolar epithelium, capillary epithelium, and the fused basement membranes between them. Ciliated respiratory mucosa is not part of the respiratory membrane.

Answer:

• Question 20: produced in the main stem bronchus
• Question 21: They serve in voice production
• Question 22: Ciliated respiratory mucosa