416
edits
Changes
Jump to navigation
Jump to search
Thermoregulation in Skin - Anatomy & Physiology (view source)
Revision as of 14:22, 12 August 2008
, 14:22, 12 August 2008→Physiology
If this insulating layer of air is replaced by water, heat is readily lost from the skin's surface, leading to a decrease in core body temperature and ultimately '''hypothermia'''. The layer is protected by secretions from the skin onto the fur or feathers. In birds, secretions from the [[The Integument of Exotic Species#Avian Skin|uropygial gland]] maintain the water repellant properties of the plumage. In mammals that are regularly exposed to water, a thick layer of subcutaneous adipose tissue of '''blubber''' is present as the insulating air is completely lost and replaced by water.
If this insulating layer of air is replaced by water, heat is readily lost from the skin's surface, leading to a decrease in core body temperature and ultimately '''hypothermia'''. The layer is protected by secretions from the skin onto the fur or feathers. In birds, secretions from the [[The Integument of Exotic Species#Avian Skin|uropygial gland]] maintain the water repellant properties of the plumage. In mammals that are regularly exposed to water, a thick layer of subcutaneous adipose tissue of '''blubber''' is present as the insulating air is completely lost and replaced by water.
===Sweating===
Sweating is controlled from a centre in the preoptic and anterior regions of the [[Nervous System - CNS - Anatomy & Physiology|hypothalamus]] where thermosensitive neurons are located. The heat regulatory function of the hypothalamus is also affected by inputs from temperature receptors in the [[Skin - Anatomy & Physiology|skin]]. High skin temperature reduces the hypothalamic set point for sweating and increases the gain of the hypothalamic feedback system in response to variations in core body temperature. Overall, however, the sweating response to a rise in hypothalamic ('core') temperature is much larger than the response to the same increase in average skin temperature.
Sweat is not pure [[water]]; it always contains a small amount (0.2 - 1%) of [[solute]].