BIO 115 Lecture Notes - Lecture 10: Phospholipid, Hydrophile, Transudate
Document Summary
Prevents continuous transudate (edema) from pulmonary capillaries to alveoli. Surfactant and oncotic pressure cause reabsorption into the capillaries - this force is stronger. Surfactant decreases surface tension by interfering with the intermolecular cohesive forces that are responsible for surface tension. Hydrostatic pressure and surface tension draw fluid into the lung. A lipoprotein complex: 30% protein and 70% phospholipid (mostly dipalmitoyl phosphatidyl choline) Synthesized in and released from the lamellar bodies in type ii alveolar epithelial cells. Becomes functional around 30 weeks of gestation even though it is being produced starting around week 18-20. Has a hydrophilic head (towards water) and a hydrophobic tail (towards air) that creates a compatible environment for both air and water in its immediate vicinity. Surfactant released into the alveoli as a result of lung distention or stimulation of beta-adrenergic receptors. Forms a monolayer along the interior lining of the alveoli (hypophase)
