The effects of the hormones depend largely on their concentration in blood and extracellular fluid. Almost inevitably, disease results when hormone concentrations are either too high or too low, and precise control over circulating concentrations of hormones is, therefore, crucial.<\/p>\n
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The concentration of hormone as seen by target cells is determined by three obvious factors\u2014the rate of production of the hormone, the rate at which it is delivered, and how long it takes to degrade.<\/p>\n
To decide how much hormone should be circulating at any given time, good control systems need to be in place. Feedback circuits are at the root of most control mechanisms in our body, and are particularly prominent in the hormonal (endocrine) system. Instances of positive feedback certainly occur, but negative feedback is much more common, particularly so for the stress hormones. We are familiar with this negative feedback control system from the air conditioners used to cool the rooms in our homes or the water tank in the toilet.<\/p>\n
In the case of air conditioners, when the temperature rises above a certain set point, cool air is blown into the room. As the room cools down and the temperature drops, a feedback is sent to the thermostat. When the temperature drops below the set point, the thermostat is triggered and the cooling stops. When the temperature rises again, the negative feedback is stopped and the cooling cycle starts.<\/p>\n","protected":false},"excerpt":{"rendered":"
The effects of the hormones depend largely on their concentration in blood and extracellular fluid. Almost inevitably, disease results when hormone concentrations are either too high or too low, and precise control over circulating concentrations of hormones is, therefore, crucial.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"class_list":["post-4706","post","type-post","status-publish","format-standard","hentry","category-stress-relief"],"yoast_head":"\n