Homeostasis is a point of balance or internal equilibrium. All kinds of systems — both living and non-living — can work to keep themselves in this state of balance, but the word "homeostasis" is most often used in biology, particularly to describe how the human body reacts to changes and keeps itself within certain parameters to ensure that it can function correctly. These reactions include a range of responses, from the release of hormones to regulate internal imbalances to sweating to lower body temperature.
Homeostasis is the process used by the body to maintain a stable internal environment. Either negative feedback or positive feedback can be used in homeostasis. In negative feedback, the body changes an internal condition back to its normal state; this is the most common way that the body regulates itself. Examples of negative feedback: (1) when blood pressure rises, the heart slows down; (2) when glucose levels in the blood are too high, the pancreas secretes insulin to stimulate the absorption of glucose and the conversion of glucose into glycogen. In positive feedback, the body reacts to a change from the normal state by causing an even greater change. Examples of positive feedback: (1) when constrictions in the uterus push a baby into the birth canal, contractions in the uterus increase; (2) when a blood vessel is damaged, the vessel constricts and chemicals are released to plug and repair the hole.
Body Temperature Homeostasis
In warm-blooded animals such as humans, body temperature must be maintained by various negative feedback reflex responses within the body. Heat in the body is generated by the cellular respiration reaction, combining oxygen and ATP (a product of glucose) and creating heat, carbon dioxide and water. The hypothalamus of...