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Politics : Sioux Nation -- Ignore unavailable to you. Want to Upgrade?

To: SiouxPal who wrote (100112)	2/20/2007 8:18:22 PM
From: Wharf Rat	Read Replies (1) \| Respond to of 362642

Study this outline; I'll be back later... (Oh, trivia; you lose 42% more moisture breathing thru your mouth as thru your nose) Gas Exchange Gas exchange occurs by diffusion from the blood to the lungs across to cell layers: an endothelial cell layer surrounding the capillary and a lung alveolar cell. Mechanics of Breathing Breathing muscles: diaphragm, external and internal intercostals Interpleural space lies between two membranes: parietal and visceral Boyles law: , PV = constant (at T=37oC), so if – V® ¯ P P: Pressure V: Volume n: number of moles R: Gas Constant T: Temperature Compliance and elasticity: . Compliance is how much a compartment will expand if the pressure in that compartment is change. A balloon has a high compliance because a small pressure increase inside the balloon will greatly expand the balloon. A rigid tube has a low compliance because a small pressure increase inside the rigid tube will not result in a significant increase in the volume of the rigid tube. Elasticity: tendency to return to initial structure after being distended Lung volumes: Tidal volume (TV) Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV) Residual volume (RV) Lung Capacities Total lung capacity = IRV + ERV + TV + RV Vital capacity = IRV + ERV + TV Functional residual capacity: ERV +RV. This volume is the equilibrium volume for the lung and the chest wall. Inspiration is active, requiring muscle contraction and expiration is passive, involving muscle relaxation. Thus at the end of passive expiration the lung (and chest wall) have relaxed back to there equilibrium position. This position corresponds to a lung volume equal to the functional residual volume. Surface tension Surface tension in the alveolus is created by interacting water molecules which direct a force inward and could caused the alveoli to collapse. . Comparing two different alveoli with the same surface tension, the smaller the radius the greater the pressure created by a given surface tension. Air will flow from high pressure (smaller alveoli) to lower pressure (larger alveoli). Thus smaller alveoli are more likely to collapse. Surfactant lowers the surface tension. This will Lower the pressure inside the alveoli making it easier to inflate the alveoli when breathing. Prevent collapse of the smaller alveoli because surfactant lowers the surface tension to a greater extent on smaller alveoli than larger alveoli. Force Vital Capacity FEV1.0: Forced expiratory volume in one second: the volume of gas that can be exhaled in 1 second after maximal inspiration. FVC: Forced vital capacity: the maximum volume that can be rapidly expired after maximal inspiration (it is approximately equal to the vital capacity, which is the maximum volume with slow expiration) Fox Textbook (7th ed) Figure 16.17, page 494: shows . Normally FEV1.0 is 80% FVC Obstructive lung disease: increased resistance to airflow caused by a reduction in the diameter of the conducting pathways. Asthma, chronic bronchitis, emphysema. Chronic obstructive pulmonary disease is chronic bronchitis and emphysema. Restrictive lung disease: scarring of lung tissue mainly due to fibrosis – elastic recoil ¯ lung compliance mcb.berkeley.edu

To: SiouxPal who wrote (100112)	2/20/2007 8:23:12 PM
From: Wharf Rat	Read Replies (1) \| Respond to of 362642

Oh, and you need to memorize this law. en.wikipedia.org Very important. Someday you may want to put in a bunch of water pipes around your place, and this will tell you how much you can move thru the pipe. You can figure that out by diameters. Other than that, pretty useless.