11-20-2011, 08:16 PM
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My some review points and images before exam. - medicalspirit
My some review points and images before exam. - medicalspirit
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My some review points and images before exam. - medicalspirit
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11-21-2011, 06:19 PM
http://www.life.umd.edu/classroom/bsci44...ture9.html
http://www.cvphysiology.com/CAD/CAD004.htm small aveoli have higher collapsing pressure and ar e harder to keep open compared to large alveoli with a low collapsing pressure and are easy to keep open. Surfactant decreases surface tension ,prevents esp. small alveoli from collapsing and increases compliance(compliance means in general to make it more like a ballon). Laplace Law puts it in mathematical terms that the pressure tending to collapse alveoli is directly proportional tosurface tension and inversely proportional to alveolar radius. P=2T/r P is pressure required to keep alveolus open T is surface tension r is radius of alveolus Most of the formulas for vessels are variants of Ohms ubiquitious law and universal law Flow equals pressure over resistance. Also in vessels wall tension is the force in the vessel to split the wall open. Laplace claims T is proportionalo to P times r T=wall tension P=pressure r=radius Law of Laplace states that transluminal pressure varies inversely with vessel radius and is directly proportional to tension that develops in the vessel walls. it means the pressure pushes against the wall causing them to stretch= tension, as the size of the vessels decreases the tension in the wall decreases too. T=Pr. T proportional to r , eg in aneurysm =more likely to burst becos of increased r even more thn aorta with more P
11-21-2011, 06:23 PM
LaPlace relationship says that wall tension (T) is proportional to the product of intraventricular pressure (P) and ventricular radius ®.
(Law of LaPlace) Wall tension can be thought of as the tension generated by myocytes that results in a given intraventricular pressure at a particular ventricular radius. Therefore, when the ventricle needs to generate greater pressure, for example with increased afterload or inotropic stimulation, the wall tension is increased (i.e., increased myocyte tension development). This relationship also shows us that a dilated ventricle (as occurs in dilated cardiomyopathy) has to generate increased wall tension to produce the same intraventricular pressure.
11-21-2011, 07:17 PM
11-21-2011, 07:55 PM
11-21-2011, 08:23 PM
11-22-2011, 03:38 PM
* collecting duct site of regulation of K+ [] in tubular fluid and urine (uw)
* http://www.medscape.com/viewarticle/730660_3 BRS physio pg 167 renin-angiotensin-aldosterone system and regulation of renal potassium (K%) excretion. Aldosterone binds to a cytosolic receptor in the principal cell and stimulates sodium (Na%) reabsorption across the luminal membrane through a well-defined sodium channel. As sodium is reabsorbed, the electronegativity of the lumen increases, thereby providing a more favorable driving force for potassium secretion through an apically located potassium channel. The permeability of the anion that accompanies sodium also influences potassium secretion, with less permeable anions having a greater stimulatory effect on potassium secretion. Disease states or drugs that interfere at any point along this system can impair renal potassium secretion and increase the risk of hyperkalemia. In many patients, this risk is magnified because of disturbances at multiple sites along this system.
11-23-2011, 03:15 PM
ADMINISTER EPINEPHRINE FOR SHOCK
Epinephrine is the drug of choice when resuscitating patients during anaphylactic shock. Alpha1-adrenergic effects produce vasoconstriction of both vascular capacitance and arterial resistance vessels to reverse hypotension; beta2 receptor stimulation bronchodilates and inhibits mediator release by increasing cyclic AMP in mast cells and basophils. http://resources.metapress.com/pdf-previ...ze=largest http://emedicine.medscape.com/article/13...view#a0104
11-24-2011, 06:12 PM
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