PHGY 210 Lecture Notes - Lecture 9: Globin, Cerebral Cortex, Dominate
25 Apr 2018
School
Department
Course
Professor
Document Summary
Alveoli = end of bronchioles, air sac, majority of ge between air/ blood. Branching of airway: connective flow, requires energy for muscle contraction maintain airflow, diffusive flow, passive action, allows air to flow into alveoli, diffusion zone begins at respiratory bronchioles. Respiration: respiratory muscles need to generate pressure gradient to move air from airways to lungs, ability of oxygen and carbon dioxide to diffuse across alveolar-capillary barrier. Allows for intrinsic tendency to deflate following inflation. Stretching lungs = elastic recoil and deflates lungs (during inspiration) Forced exerted by liquid lining inside alveoli (70% of elastic recoil of lungs) Law of laplace: magnitude of collapsing pressure is directly proportional to surface tension. Inversely proportional to radius of alveoli: decrease size = increase collapsing pressure. 2t (surface tension)/ r (alveolar radius) = p (collapsing pressure) Alveolar pressure (pa) = pleural pressure (p ) = lung recoil pressure (pi)
