Homeostasis - Essay Example

Download file to see previous pages The term homeostasis was first used by Walter Cannon in 1932 to illustrate the “maintenance of body’s dynamic constancy”. Homeostasis is a key concept in human physiology which represents the regulatory processes of the body for its optimum functioning mediated by several biochemical and physiological pathways. According to Gilbert, on a cellular level it is a practice through which a relatively constant electrical, chemical, osmotic and internal environment is maintained against a background of extensive range of metabolic demand, intake and loss. Maintenance of homeostasis is vital for the body as seen during exercise. The elevated cardiac and respiratory rates in response to increased CO2 and blood acidity must be readjusted later to meet the demand of lower metabolic rate. If this service is not done the body conditions lead to disease and ultimately death. Homeostasis is maintained by stimulus identification at tissue level with the help of sensors present in skin and sensory organs. These signals are then sent to peripheral sensory nerves and later to spinal cord and brain where depending on the type of stimulus a chain of physiological reaction is set off to maintain homeostasis in the body which may involve survive mechanism, stability in autonomic functions and immunological responses (Lawton, 2003). These responses are carried out by effectors such as muscles and glands. In some cases the responses to a stimulus are particularly elicited by either nervous or endocrine system however, in some cases it is a combination of both (Farabee, 2006). The process through which a constant internal environment (homeostasis) is maintained is known as homeostatic mechanism. Homeostatic control in the body is achieved through feed-back system which may be negative feed-back loop or positive feed-back loops. Negative feed-back loops (employed by most of the body’s systems) turns off the response to a particular stimulus thereby maintaining most of homeostatic activities while positive feed-back loop intensifies the effect of the particular response (Farabee, 2006). Positive feed-back intensifies the effects of change and therefore does not play a vital role in maintaining homeostasis. Stimulus? Sensor?Integrator? Effector Negative feed-back loop Systems involved in homeostasis: In a healthy body homeostatic maintenance is done by collaborative efforts of central systems of the body such as nervous, endocrine, circulatory, digestive and lymphatic. The balancing responses of these systems to a stimulus tend to maintain a proper homeostasis in body (Lawton, 2003). Major homeostatic controllers of the body are nervous and endocrine systems which constitute extrinsic control system. However, local or intrinsic control system usually involves an organ or a tissue e.g. dilation of blood vessels in reaction to higher levels of carbon dioxide and lower oxygen levels (Farabee, 2006).  ...Download file to see next pagesRead More