Question

Describe the morphology of the alveolus and identify the type I and type II alveolar cells and indicate their function

a) Squamous, Cuboidal, Pneumocytes, Gas Exchange, Surfactant Production
b) Cuboidal, Columnar, Macrophages, Mucus Secretion, Antibody Production
c) Spherical, Spindle-shaped, Interstitial Cells, Collagen Synthesis, Elasticity
d) Circular, Irregular, Lymphocytes, Phagocytosis, Hormone Release

Answer 1

The alveoli are composed of type I alveolar cells (squamous epithelial cells) for gas exchange, type II alveolar cells (cuboidal epithelial cells) for surfactant production, and alveolar macrophages for immune defense. The correct option is A.

Step-by-step explanation:

The alveolus is a critical structure in the respiratory zone responsible for gas exchange. The morphology of the alveolus includes three major cell types: type I alveolar cells, type II alveolar cells, and alveolar macrophages.

Type I alveolar cells are squamous epithelial cells that make up approximately 97 percent of the alveolar surface area, being highly permeable to gases due to their thinness, approximately 25 nm.

On the other hand, Type II alveolar cells, which are dispersed among Type I cells, are cuboidal epithelial cells that have a key function in secreting pulmonary surfactant, which is vital in reducing the surface tension within the alveoli to prevent their collapse during exhalation.

Alveolar macrophages roam the alveolar walls, acting as phagocytic cells of the immune system, tasked with the removal of debris and pathogens that reach the alveoli.