Answer:
Explanation:
Homeostasis is the tendency to resist change in order to maintain a stable, relatively constant internal environment.
Homeostasis typically involves negative feedback loops that counteract changes of various properties from their target values, known as set points.
In contrast to negative feedback loops, positive feedback loops amplify their initiating stimuli, in other words, they move the system away from its starting state.
Introduction
What's the temperature in the room where you're sitting right now? My guess would be that it's not exactly 98.6\,^\circ\text F98.6
∘
F98, point, 6, degrees, start text, F, end text/ 37.0\,^\circ\text C37.0
∘
C37, point, 0, degrees, start text, C, end text. Yet, your body temperature is usually very close to this value. In fact, if your core body temperature doesn't stay within relatively narrow limits—from about 95\,^\circ\text F95
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F95, degrees, start text, F, end text/ 35\,^\circ\text C35
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C35, degrees, start text, C, end text to 107\,^\circ\text F107
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F107, degrees, start text, F, end text/ 41.7\,^\circ\text C41.7
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C41, point, 7, degrees, start text, C, end text—the results can be dangerous or even deadly.^1
1
start superscript, 1, end superscript
The tendency to maintain a stable, relatively constant internal environment is called homeostasis. The body maintains homeostasis for many factors in addition to temperature. For instance, the concentration of various ions in your blood must be kept steady, along with pH and the concentration of glucose. If these values get too high or low, you can end up getting very sick.
Homeostasis is maintained at many levels, not just the level of the whole body as it is for temperature. For instance, the stomach maintains a pH that's different from that of surrounding organs, and each individual cell maintains ion concentrations different from those of the surrounding fluid. Maintaining homeostasis at each level is key to maintaining the body's overall function.
So, how is homeostasis maintained? Let's answer this question by looking at some examples.
