What is the primary function of type I alveolar cells?

What is the primary function of type I alveolar cells?

• A. Produce surfactant
• B. Facilitate gas exchange
• C. Secrete mucus
• D. Regulate airway resistance

Answer: (B)

Type I alveolar cells, also known as type I pneumocytes, play a critical role in the primary function of the alveoli, which is gas exchange. These cells are thin, flat epithelial cells that line the alveolar surface, providing a large surface area for the diffusion of oxygen and carbon dioxide between the air in the alveoli and the blood in the capillaries. Their structural characteristics allow for minimal barrier thickness, facilitating the efficient transfer of gases. The extensive surface area of the alveoli, composed primarily of type I cells, ensures that a sufficient amount of gas can be exchanged during each breath, making them vital to the respiratory process and overall oxygenation of the blood. While other cell types in the lungs, such as type II alveolar cells, are responsible for producing surfactant to reduce surface tension and help keep the alveoli open, or goblet cells that secrete mucus, the primary function of type I alveolar cells is indeed to facilitate gas exchange. Hence, option B accurately reflects their essential role in pulmonary physiology.

Type I alveolar cells, also known as type I pneumocytes, play a critical role in the primary function of the alveoli, which is gas exchange. These cells are thin, flat epithelial cells that line the alveolar surface, providing a large surface area for the diffusion of oxygen and carbon dioxide between the air in the alveoli and the blood in the capillaries.

Their structural characteristics allow for minimal barrier thickness, facilitating the efficient transfer of gases. The extensive surface area of the alveoli, composed primarily of type I cells, ensures that a sufficient amount of gas can be exchanged during each breath, making them vital to the respiratory process and overall oxygenation of the blood.

While other cell types in the lungs, such as type II alveolar cells, are responsible for producing surfactant to reduce surface tension and help keep the alveoli open, or goblet cells that secrete mucus, the primary function of type I alveolar cells is indeed to facilitate gas exchange. Hence, option B accurately reflects their essential role in pulmonary physiology.