Welcome to my blog!
I will be blogging about everything we will learn in Ms. Birekeland's Biology 12 class this year. My first entry is about homeostasis. Homeostasis means to 'stay the same', which is the ability of life to maintain a constant, stable and organised environment. In order to do this, humans have sensitive receptors which moniter each condition and keep the body under homeostatic control. Examples include making sure the temperature, blood pressure, sugar levels, osmolarity, and pH remain at the same level. Moniters are linked and a linked series of receptors and corrective mechagnisms is formed. These feedback loops can be either positive or negative.Negative feedback loops will shut off at a certain set point. If a stimulus occurs, for example if the body temperature rises above 37.5 degrees celcius, a message goes to the receptor. The receptor in this case is is the thermoreceptor. The job of the hypothalamus is to maintain a set point of 37.5 degrees in the body. This is the regulatory center. From there, an effoector is activated, in this case the sweat glands, and your body will begin to sweat. A response will occur; the arterioles will dilate, flushing the sweat. Once your body cools down back to its normal temperature, the system shuts itself off.
Positive feedback loops occur when the product of an initial product stimulates, or causes another pathway to increase activity. An example of this is labour.
