Biology 1002B Study Guide - Quiz Guide: Bronchus, Atmospheric Pressure, Cardiac Output
Document Summary
Non-resp lung functions: defensive filter out particulates/microbes, metabolic 100% of cardiac output, endocrine prostaglandins, angiotensin , haemotologic filtering. Immunologic muco-ciliary escalator, macrophages: thermoregulatory, water-eliminative, phonation speech. Metabolic rate = vo2 (oxygen consumption) in mls/min. Rq at steady state depends on food being metabolised. If only fat rq=0. 7: mixed diet rq=0. 8. Rq less than 1 because more o2 needed for metabolism. Lungs must accommodate 30-fold inc in gas transfer. Z17+ gas exchange because membrane thin enough. No gas exchange in conducting zone airways. Diameter decreases as number inc from trachea alveoli. As area (a) increases down airways speed (v) of air movement through lungs increases. Beyond z17 gas speed doesn"t increase anymore that of diffusion not convection speed of molecular diffusion. Above z17 gas movement dependant on convection pressure gradients from breathing. Diffusion depends upon partial pressure gradients greater chemical gradient, greater rate of flow. *note: diffusion is limiting at high altitudes because less dense so smaller conc. gradient.
