PHGY 214 Lecture Notes - Lecture 2: Pulmonary Compliance, Alveolar Pressure, Viscosity
12 May 2016
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Document Summary
Mechanics: express the relation between flow, pressure and resistance. Airways smooth muscles regulate resistance to flow. Flow : express the relation between resistance and the viscosity of the fluid, the length of the tube, and the radius of the tube (poiseuille"s law, state the most common unit of measurement of pressure in respiratory physiology. Most respiratory physiologists use cmh20: convert pressures in mmhg to cmh2o and vice versa. 1mmhg = 1. 36cmh20: explain the difference between absolute and relative (to barometric) pressures. Barometric pressure is the weight of the atmosphere (absolute pressure) In respiratory physiology, ambient barometric pressure is set equal to zero, and all other pressures are relative to this value (relative pressure: list the three forces opposing movement of air into and out of the lungs. Tone of airway smooth muscle (active) degree of contraction. Is regulated by inputs from the ans branches (sympathetic and parasympathetic) The parasympathetic is dominant at rest when ventilator demands are low.
