undertand that homoeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis.
-negative feedback loop- method of control and maintaining constant conditions.
-in the case of humans our fixed body point is our body temperature (around 37/38 degrees)
- in order for it to work we have receptors- hypothalamus (region of the brain)
-responds to the stimulus- temperature of body and blood.
-body temp feeds into the brain and is compared- if the body temp needs to be increased or decreased then it is brought about bye the effectors eg. skin.
-response is either decrease or decrease in body temp. feedback to the hypothalamus, and based on the input, a new output would be produced.
-x axis- time
-level on y- regulation points 37/ 38 degrees
-if the body temp increase- input to hypothalamus, stimulates response in the skin for cooling- sweating
and increased of blood flow to surface of skin.
-blood vessels dilate (widen) so more blood can flow to the surface.
-increases exchange of heat to outside of body by evaporation of sweat and radiation.
-this brings about the cooling of blood which returns body temp to fix level
-if body temp falls, this feeds to the hypothalamus and switches on regulation to increase the body temp- causes shivering, raised hairs.
-forces blood to travel deeper through tissue and reduces heat exchange with external environment.
-temp varies (of blood) up and down around the fixed point (37/38) making efficiency of the system is determined by how far they deviate from fixed point.
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