Question

Which of the following is correct about alveolar type I and II cells?

A. Alveolar type II cells make up the alveolar membrane and alveolar type I cells produce surfactant.
B. Alveolar type I cells produce mucus and alveolar type II cells act to clear debris from the alveoli.
C. Alveolar type I cells act to clear debris from the alveoli and alveolar type II cells produce mucus.
D. Alveolar type I cells make up the alveolar membrane and alveolar type II cells produce surfactant.

Answer 1

Alveolar type I cells make up the alveolar membrane and are involved in gas exchange, while alveolar type II cells produce surfactant, which reduces the surface tension in the alveoli. The correct statement is D, with type I cells constituting the alveolar surface and type II cells secreting surfactant.

Step-by-step explanation:

The correct statement about alveolar type I and type II cells is: Alveolar type I cells make up the alveolar membrane and are squamous epithelial cells that are highly permeable to gases. They constitute up to 97 percent of the alveolar surface area. On the other hand, alveolar type II cells are interspersed among the type I cells and are responsible for secreting pulmonary surfactant, a substance composed of phospholipids and proteins that reduces the surface tension of the alveoli, preventing their collapse during expiration. Therefore, the correct answer is D. Alveolar type I cells make up the alveolar membrane, whereas alveolar type II cells produce surfactant.

Moreover, alveolar macrophages roam the alveolar walls and are involved in removing pathogens and debris, not type I or type II cells. Type I and type II cells focus on gas exchange and surfactant production, respectively

Answer 2

The following is correct about alveolar type I and II cells: D. Alveolar type I cells make up the alveolar membrane, and alveolar type II cells produce surfactant.

Step-by-step explanation:

Alveolar type I cells are responsible for forming the structural framework of the alveoli, making up the alveolar membrane. These cells are thin and flat, facilitating gas exchange. On the other hand, alveolar type II cells produce surfactant, a substance that reduces surface tension within the alveoli, preventing their collapse and facilitating efficient gas exchange. Surfactant is crucial for maintaining lung compliance and preventing respiratory distress. Options A, B, and C provide incorrect information about the roles of alveolar type I and II cells.

Option D is the answer.