Concept of homeostasis
For example, when overheatedwe may shed a layer of clothing, move into the shade, or drink a cold glass of water. Canadian-born American ecologist Robert MacArthur first proposed in that homeostasis in ecosystems results from biodiversity the variety of life in a given place and the ecological interactions predationcompetitiondecomposition, etc.
The kidneys respond by excreting sodium ions into the urine, thereby normalizing the plasma sodium ion concentration. Instead of measuring it directly in the blood flowing past the juxtaglomerular cells , these cells respond to the sodium concentration in the renal tubular fluid after it has already undergone a certain amount of modification in the proximal convoluted tubule and loop of Henle. Instead of lowering the oxytocin and causing the pain to subside, more oxytocin is produced until the contractions are powerful enough to produce childbirth. What is an example of homeostasis in a mechanical system? Fluid balance involves keeping the fluid volume stabilized, and also keeping the levels of electrolytes in the extracellular fluid stable. Osmotic pressure is detected by osmoreceptors in the median preoptic nucleus in the hypothalamus. Both internal and external events can induce negative feedback mechanisms. Diabetes occurs when the control mechanism for insulin becomes imbalanced, either because there is a deficiency of insulin or because cells have become resistant to insulin. Image credit: Shutterstock Keeping information flowing Homeostatic systems may have primarily evolved to help organisms maintain optimal function in different environments and situations. The converse happens when a high plasma pH stimulates the kidneys to secrete hydrogen ions into the blood and to excrete bicarbonate into the urine. Figure If blood pressure is too high, the heart rate decreases as the blood vessels increase in diameter vasodilation , while the kidneys retain less water. It is very probable that the renal tubular cells of the distal convoluted tubules are themselves sensitive to the pH of the plasma. The result is the maintenance of an elevated blood pressure that can have harmful effects on the body.
The term homeostasis has been used by many ecologists to describe the back-and-forth interaction that occurs between the different parts of an ecosystem to maintain the status quo. Concept in Action Watch this Discovery Channel video on thermoregulation to see illustrations of this process in a variety of animals.
Instead of lowering the oxytocin and causing the pain to subside, more oxytocin is produced until the contractions are powerful enough to produce childbirth.
Animals that do not control their body temperature are ectotherms.
The processes of homeostasis and temperature control are centered in the hypothalamus of the advanced animal brain. The hypothalamus then sends a message to the heart, blood vessels, and kidneys, which act as effectors in blood pressure regulation.
Finally, heat itself may also kill the pathogen. Anything that prevents positive or negative feedback from working correctly could lead to disease if the mechanisms of disruption become strong enough.
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