Anatomy and Physiology Answer Key

G muscular dystrophy and obesity 5 it is only through

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Unformatted text preview: its ability to produce a concentrated urine. When salt transport is inhibited, the ability to concentrate the urine is also impaired and urine volume increases as a result. Fluid and Electrolyte Balance (page 204) 1. The intracellular fluid compartment is the fluid found within the body's cells. it accounts for 60-65% of the body's water and is important for the metabolic reactions occurring within their fluid environment. Biozone International 2009 Photocopying Prohibited (a) Fall in blood volume caused by blood loss (as a result of trauma) or a sudden loss of blood pressure (e.g. as a result of shock) or a drop in electrolyte levels. (b) A drop in blood volume is detected by the juxtaglomerular cells of the kidney which monitor the blood in the afferent arteriole of the glomerulus. They respond by producing the enzyme renin, which catalyzes the formation of angiotensin II in the blood. It is angiotensin II that causes blood vessels to constrict (which raises blood pressure) and stimulates the adrenal cortex to release aldosterone (which causes tubular reabsorption of sodium and water by osmosis). Angiotensin II also stimulates the thirst center of the hypothalamus to promote drinking. When blood volume increases, the juxtaglomerular cells cease to be stimulated and renin production falls. Anatomy and Physiology The salt gradient allows water to be withdrawn from the urine (allows the urine to be concentrated). Note: Because the salt gradient increases through the medullary region, the osmotic gradient is maintained and water can be continually withdrawn from the urine. 2. 34 Kidney Dialysis (page 206) 1. The dialysing solution is constantly been replaced because it needs to be free of urea and other wastes in order to maintain the concentration gradient between the blood and the dialysate. Without a gradient, urea and other wastes would stay in the blood. 2. Other ions and small molecules do not diffuse into the dialysate because they are at a similar concentration in both blood and dialysate, i.e. the dialysate has a similar ionic composition to blood and there is no concentration gradient for these molecules. T...
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This document was uploaded on 01/28/2014.

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