MEDICAL PHYSIOLOGY

Detailed explanation-1: -Type 2 pneumocytes are alveolar cells that secrete surfactant proteins to reduce surface tension.

Detailed explanation-2: -Type II pneumocytes are identified as the synthesizing cells of the alveolar surfactant, which has important properties in maintaining alveolar and airway stability. Lung surfactant can reduce the surface tension and prevent alveolar collapse and the airway walls collapse.

Detailed explanation-3: -Pulmonary surfactant is produced by alveolar type II cells and is required for lung function after birth. Pulmonary surfactant is composed of lipids and four lipid-associated proteins, SP-A, SPB, SP-C, and SP-D, that regulate surfactant function, structure, metabolism, and innate host defense.

Detailed explanation-4: -Type II cells are spherical pneumocytes which comprise only 4% of the alveolar surface area, yet they constitute 60% of alveolar epithelial cells and 10-15% of all lung cells.

Detailed explanation-5: -Type 2 pneumocytes secrete surfactant Their nuclei are round and dark-staining, and their cytoplasm is rich in mitochondria and both rough and smooth endoplasmic reticulum.