BIOLOGY 20 Lecture Notes - Lecture 31: East Los Angeles College, Mediastinum, Pulmonary Pleurae
Document Summary
Each alveolus surrounded by a basket of blood capillaries supplied by the pulmonary artery. Respiratory membrane the barrier between the alveolar air and blood. Endothelial cell of blood capillary their shared basement membrane important to prevent fluid from accumulating in alveoli. Respiratory distress syndrome lack of surfactant: infants are not strong enough to inflate their alveoli. Protein rich fluid leaks into the alveoli forming a membrane which further blocks oxygen uptake treatment with mechanical ventilation may cause bronchopulmonary dysplasia and chronic respiratory insufficiency over time. Surfactants are suspended in saline and administered into the airways through a endotracheal tube. Coats alveolar surfaces and reduces surface tension. Create pressure gradient: lower pressure than atmospheric pressure and assists lung inflation. Compartmentalization: prevents spread of infection from one organ in the mediastinum to others. Intrapulmonary pressure intra alveolar pressure ie the pressure within the lungs which varies with inspiration and expiration intrapleural pressure.
