Water - cells. Cells in hypertonic solutions lose water and...

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Water Unsurprisingly, maintaining the proper amount of water in the body is essential. Recall that we are essentially bags of water with solutes dissolved in it. Several mechanisms contribute to water homeostasis, which will be discussed later. However, it is important to understand what happens to cells if water balance is not maintained. The correct amount of water in the body results in an isotonicity , where the amount of solutes (and therefore water) is the same inside and outside the cell. Cells in isotonic solutions keep their correct shape. However, if the body becomes over- watered, then the solutions surrounding our cells becomes hypotonic . Cells in hypotonic solutions take on water and swell or burst. In contrast, dehydration results in hypertonicity , where the cells are in a solution that has many more solutes (and therefore less water) than the
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Unformatted text preview: cells. Cells in hypertonic solutions lose water and shrink. Figure 3 Positive Feedback Loops Negative feedback is a process that enables the body to maintain homeostasis by effecting changes in the body to maintain the proper "set point". In contrast, positive feedback results in self-amplifying changes. For instance, if you cut yourself, the blood begins to clot. Under negative feedback, the result would be destruction of the clot and continued bleeding. But blood clotting works by positive feedback, where the clotting results in more clotting and ceases the loss of blood. Similarly, child birth is positively controlled. Once labor starts, changes in the body result in increasing uterine contractions and expulsion of the fetus....
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