homeostasis

Homeostasis maintains the body’s internal environment it allows organs and cells to function at their best. It keeps the body at steady state, this refers to the fact that conditions need to remain constant, if not then normal function would be disrupted. However there is a certain limit set , this is due to the changing values , rather they are maintained around an ideal value which is also known as the set point.
The skin regulates most of the body temperature and uses a mechanism called negative feedback with a control centre , receptor and effector in the nervous system, this is to reverse any change. The skin is divided into two layers: the epidermis and the dermis. The epidermis is the outer layer, this contains pores which sweat exits the body from. The dermis is the second layer underneath; this has most of the effectors used to control the body’s temperature.
With the change of body temperature, receptors, normally nerve endings, in the dermis encounter the change, then sends an impulse to the hypothalamus, the control centre in the brain. An impulse is then sent to the effectors in the skin and will respond in either increasing or decreasing temperature; this would depend on the change. Responses are carried out by the structure in the dermis. When temperature goes back to its set point the hypothalamus then stops sending impulses to the effectors. This process is the negative feedback.
Hair follicles are seen on the outside of the skin and are the root of the hairs. With the decrease of temperature, muscles attach to the follicle. The erector Pilli cause the hair to stand through contracting which in turn traps hair which acts as an insulator. With the increase of temperature the erector Pilli relaxes and hairs naturally lie flat. Blood vessels within the human body also play a vital part for the homeostasis of the body. Parker (2007) demonstrates the vasodilation process; this is dilation of the blood vessels once body temperature increases,