Thursday, September 6, 2012

Homeostasis

I bet that when you hear the word homeostasis, you probably wonder what it means. I know that when I first heard it I wondered what it meant. Homeostasis is the ability to maintain a relatively stable internal environment In an ever-changing outside world. The internal Environment Of the body is in a dynamic state of equilibrium, so chemical, thermal, and neural factors interact to maintain homeostasis. Most homeostatic is controlled by the release of hormones into the bloodstream.
      With Homeostatic Control Mechanisms, the variable produces a change in the body. The three interdependent components of control mechanisms are the receptor, the control center, and the effector. The receptor monitors the environments and responds to changes (stimuli). the control center determines the set point at which the variable is maintained. And the effector provides the means to the stimulus.
    This is a chart that kind of puts the control mechanisms into a better understanding for you.


     Watching a video in our Anatomy and Physiology a couple days ago showed us some of the things that homeostasis deals with. They were showing a race and all the the things you need to keep track of when you are running a marathon rice like that. There are actually more things that go to it when you are talking about your heart rate, temperature, weight, fuel for glucose levels, and breathing. They kept track of one particular woman's levels throughout a race and everything was pretty good throughout the race, but towards the end some things started going a little wrong. She stayed hydrated through the race and was well hydrated before the race. At the end she had lost five pound from sweating all her hydration off and all of her rates started to go back to normal. When you are doing a physical activity like that you have to know that all of your levels of heart rate, temperature, your breathing rate, glucose levels and everything are either going to drop or rise, but most likely rise. When all of your levels or rates start to go back to normal that isn't always the best thing because that is called negative feedback. In negative feedback the output shuts off the original stimulus.

There is also something called Positive feedback. With positive feedback systems, the output enhances or exaggerates the original stimulus. An example of this would be the regulation of blood clotting. With this  there could be a break or tear in the blood vessel wall which causes the feedback cycle to initiate. The clotting occurs as platelets adhere to site and release chemicals. Then the feedback cycle just ends. Released chemicals start to attract more platelets, The clotting then proceeds until the break is sealed by a new clot that forms. And thats pretty much how a positive feedback cycle works.
     There is also something called Homeostatic Imbalance. With homeostatic imbalance there is a disturbance of the bodies normal equilibrium. It pretty much goes crazy! Overwhelming of negative feedback mechanisms allow destructive positive feedback mechanisms to take over. This is definitely something that you don't ever want to happen!