Homeostasis
Homeostasis is a self-regulating process through which an organism tends to maintain a state of equilibrium or a constant internal environment for stability. Internal environments of organisms require constant adjustments to be stable because conditions change continuously in and out of the cell. Adjustments should be made continuously to keep the cell at the normal level or near the set point with which it can operate normally. The process by which systems adjust themselves to get at an equilibrium is called homeostatic regulation. Stability attained is actually dynamic equilibrium in which some slight continuous changes continue occurring and yet uniform conditions prevail. The endocrine systems release hormones that will regulate body cell activity. The stimulus controls hormone secreted that help in controlling the internal and external conditions of the prevailing cell. The self-regulating processes are called the feedback response mechanism.
Feedback Mechanisms
Negative Feedback Mechanism
All homeostatic processes that change the direction of a given stimulus is referred to as a negative feedback mechanism. If a level is too high, the body acts in a direction to lower it down to an equilibrium. Conversely, if the level is too low, the body acts in the direction of raising back to a balance. For example, the regulation of glucose levels in the blood sugar explains the negative feedback. When levels of blood sugar rise, body receptors sense and stimulate the pancreas to secrete insulin hormone which lowers the blood sugar level to an equilibrium. The vice versa is applicable when the blood sugar levels are low, the body receptor cell stimulates the pancreas to produce glucagon hormone which breaks down glycogen to release glucose. The glucose will raise the levels of sugar in blood.
Positive Feedback Mechanism
A positive feedback mechanism maintains the direction of the stimulus. The output from the mechanism enhances the original stimulus. Blood clotting is a perfect example for positive feedback mechanism. When an organism is injured, receptor cell stimulates the blood to release platelets to cover up the injured site. Released platelets will release chemicals that will stimulate the production of more platelets, thus speeding up the healing process. The positive feedback mechanism hastens the process of healing.