let me tell you what will happen when our surrounding gets too warm ( which in turn, causes our body temperature to rise) and how our wonderful body adjusts to maintain our body temperature within normal range ( which is bet 35.8-37.7 degree celcius ) .
Homeostasis regulation occurs to maintain the body temperature within normal range. it means 'staying similar' as the tissue fluid in our body are being adjusted all the time to prevent chemical reaction from speeding up or slowing down when surrounding temperature changes.
Homeostatic regulation involves a receptor: sensitive nerve fibres on the skin which detects environmental changes (stimulus), control centre/integration centre: the brain, which processes information sent by the receptor with the help of the hypothalamus ( a form of thermostat of the body) and then sents out commands to the effector: which will respond to the commands of control centre and do what is necessary to keep the body temperature within normal range.
When the temperature of the surrounding get too warm, the receptor will detect the stimulus and sends information to the the control centre. since the temperature is too high for the body, the hypothalamus detect the abnormality and the brain will send out commands to the effector to lower the body temperature. The effector, which in this case is the skin will start sweating. Sweat glands will secrete sweat on to the skin surface to let the sweat evaporate and thus taking away the latent heat. this way, the body cools down.
Vasodilation will also occur. During vasodilation, the muscle tissues relax causing blood vessels in the dermis to dilate, allowing more blood flow near the skin so that heat can be lost through convection and then through radiation from the skin to the surroundings.
The effector responds by causing the body to sweat and vasodilation to happen, in order to keep the body cool when the surrounding is too warm.
However, when the surrounding gets to cold, the body will react differently. the recpetor will detect the environmental change and quickly sends information to the control centre. upon receiving information, the hypothalamus knows that it is too clod and thus the brain commands the effector to keep the body warm. the effector will then cause the constriction of sweat glands to reduce heat loss by evaporation.
Blood vessels in the dermis will constrict to reduce blood flow near the skin which prevents heat loss through convection. More blood will go to the internal organs such as the brain and intestines to conserve heat energy. this process is called vasoconstriction.
The body will also start to experience an uncontrollable burst of rapid muscular contraction in the limbs which releases heat to keep the body warm as a result of respiration in the muslces. This is called shivering. Besides that, the body hair will also stand in attempt to trap heat.
Outgoing impulses conteract the effects which produced the incoming impulses. this negative feedback controls the body temperature as stimulus and response work opposite of each other. A rise in the body temperature is detected by the thermoregulatory centre and sends nerve impulses to the skin which resluts in vasodilation and sweating whereby the body reacts to cool itself.
However, body temperature varies from moment to moment because of the small oscillation around the set point ( the hypothalamus ) or changes in the set point which maybe due to different environment, different level of activity or virus attack which alters the set point.
So whenever the surrounding gets too warm or too cold, the body will react to keep itself within the normal temperature range.
* please take note that this essay is written by an ameuter and information may not be that accurate. For better understanding please refer to Martini, FH Essential of Anatomy andPhysiology 4th edition. This book costs $61 can be bought at NP bookshop (which is located at the atrium) or any leading bookstore ( does not include popular).
