The Importance of Homeostasis Within The Human Body

Homeostasis is the maintenance of a constant internal environment within an organism or cell to maintain equilibrium, usually using a system of feedback controls to stabilise health and proper functioning. Homeostasis can control steady water levels, blood sugar level and temperature which are vital in survival as they can be changed depending on the external environment, whether being in a cold or hot climate, the body will adapt internally in order to keep itself functioning. The human body has receptors to detect stimuli, processing centers which receive information, a coordinator which receives and controls the information from the receptor and triggers the response that will correct the change and an effector that carries out the action that will bring about the change.

For example, the body’s temperature must remain at 37 degrees Celsius as this is the temperature at which enzymes can function optimally. There are temperature receptors found within the skin which detect change in the external environment and then this information is passed onto the hypothalamus as it is the brain’s processing centre and it also has receptors that can detect change in blood temperature. Whenever the internal or external temperature changes, the hypothalamus will trigger a change in the body’s effector (in this case sweat glands and muscles) to maintain the correct temperature. If it discovers that the body is too hot, glands within the skin will secrete sweat onto its surface to increase heat loss by evaporation. If the body is too cold, muscles in the skin contract, causing the hair on the arms to stand up straight which in turn traps a layer of warm air next to the skin to prevent heat loss. This happens all over the body in many different ways in order to maintain stability in the body or the body could malfunction.

Glucose level within the bloodstream must be maintained in homeostasis, so when this level changes, the body will react to correct it. When there is an increase in glucose levels in the blood, for example, eating glucose rich food such as fruit and vegetable, the increase of the glucose level in the blood will be detected by the beta cells found in the pancreas. The pancreas then releases insulin into the bloodstream which helps the liver to take up the glucose and break it down into glycogen to be stored. Insulin increases the rate of respiration within the body cells, therefore increasing the glucose uptake which helps in the regulation of the glucose level in the blood. This is a negative feedback loop because the change detected was an increase and this had to be reduced.

When there is a decrease in glucose level in the blood, for example, not eating for an entire day, the alpha cells in the pancreas will detect this change and glucagon will be released. The glucagon will facilitate the breakdown of glycogen stored to glucose within the liver and released into the bloodstream, therefore increasing the glucose level in the blood. This is a positive feedback loop as the change detected was a decrease so there needed to be an increase to correct it.

Hyperglycemia is when the glucose level is above the normal range (980mg-100mg/100ml), this can be a result of type 1 diabetes where the body cannot make insulin, or type 2 diabetes where the body cannot respond to insulin properly, so the glucose builds up in the blood. This can result in damaging the vessels that supply blood to vital organs, increasing risk of heart disease/stroke, kidney disease, vision problems and nerve problems for diabetic people. Hypoglycemia is the opposite, where the level of glucose in the blood is lower than the normal range which can be a result of not eating, or not taking diabetic medicine and can result in confusion, seizures or death.

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