Thursday, September 3, 2015

Let's Talk About Homeostasis

Today we are going to talk about homeostasis and figure out exactly what it is, while learning about some examples and important terms.

To begin, let's find out what homeostasis means. By definition, it is "the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes." So, essentially, homeostasis is where the body uses physiological processes to maintain a balance and stable environment within the body.




We are constantly putting our bodies through changing environments and altering the patterns of what we consume, but even so, our bodies manage to stay balanced through homeostasis. For example, when the environment outside of the body is cold, homeostasis makes sure the internal systems inside the body keep it at the correct temperature. 


The picture above illustrates another example of homeostasis. As you run, your body generates more heat than when you are at rest. Your body is also subjected to the weather outside, and must adapt to the temperature to maintain an internal balance. To do this, homeostasis causes increased respiratory, sweat, and radiation production. 

Another important part of homeostasis is feedback. Feedback is separated into two categories: positive and negative. 

Negative feedback- "the diminution or counteraction of an effect by its own influence on the process giving rise to it, as when a high level of a particular hormone in the blood may inhibit further secretion of that hormone, or where the result of a certain action may inhibit further performance of that action."

Negative feedback isn't a "bad" thing. Basically, something happens to your body, such as an increase in your blood glucose level, and as a result, your body has a reaction, such as secreting insulin that stores the glucose as glycogen. Because of the insulin reaction, your body begins to detect lower levels of glucose, and therefore, slow insulin secretion. This is negative feedback; your body was able to balance blood glucose levels by starting/stopping insulin production. This example is illustrated below.


Positive Feedback-"the enhancement or amplification of an effect by its own influence on the process that gives rise to it."

Positive feedback is basically where your body detects something and reacts to the change. Unlike negative feedback, the body continues to react until the disturbance is completely controlled. For example, when a woman is giving birth, the baby's head being pushed causes nerve impulses which lead to the contraction of the uterus. This pushes the baby forward, and again, a contraction occurs. this cycle repeats until the baby is pushed out. This example is also shown below. 


So there it is-the basics of homeostasis, its functions, and positive/negative feedback!



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