Functions
Skin performs the following functions:
- Protection: an anatomical barrier from pathogens and damage between the internal and external environment in bodily defense; Langerhans cells in the skin are part of the adaptive immune system.
- Sensation: contains a variety of nerve endings that jump to heat and cold, touch, pressure, vibration, and tissue injury (see somatosensory system and haptic perception).
- Thermoregulation: eccrine (sweat) glands and dilated blood vessels (increased superficial perfusion) aid heat loss, while constricted vessels greatly reduce cutaneous blood flow and conserve heat. Erector pili muscles in mammals adjust the angle of hair shafts to change the degree of insulation provided by hair or fur.
- Control of evaporation: the skin provides a relatively dry and semi-impermeable barrier to fluid loss.
- Storage and synthesis: acts as a storage center for lipids and water
- Absorption: oxygen, nitrogen and carbon dioxide can diffuse into the epidermis in small amounts; some animals use their skin as their sole respiration organ (in humans, the cells comprising the outermost 0.25–0.40 mm of the skin are "almost exclusively supplied by external oxygen", although the "contribution to total respiration is negligible")
- Water resistance: The skin acts as a water resistant barrier so essential nutrients aren't washed out of the body. The nutrients and oils that help hydrate our skin are covered by our most outer skin layer, the epidermis. This is helped in part by the sebaceous glands that release sebum, an oily liquid. Water itself will not cause the elimination of oils on the skin, because the oils residing in our dermis flow and would be affected by water without the epidermis.
Read more about this topic: Skin
Other articles related to "functions, function":
... make assumptions about the room's original functions and how those functions may be similar to or differ from kivas used in modern practice ... This suggests that the room's older functions may have been changed or adapted to suit the new religious practice ...
... For more details on this topic, see elementary function (differential algebra) ... The logarithm and the exponential function are examples of transcendental functions ... Transcendental function is a term often used to describe the trigonometric functions (sine, cosine, tangent, their reciprocals cotangent, secant, and cosecant, the now little-used versine, haversine, and ...
... The Vice-President performs some important functions and duties ... If the President is not able to perform his functions due to absence or illness etc ... the Vice-President shall perform the functions of President until the President resumes his duty ...
... Following are several candidates for one-way functions (as of April 2009) ... Clearly, it is not known whether these functions are indeed one-way but extensive research has so far failed to produce an efficient inverting algorithm for any of them ...
... Since 1999 InCopy from Adobe is a direct competitor to QuarkCopyDesk, which was launched in 1991 ... QuarkCopyDesk offers three viewing modes Story, Galley and WYSIWYG ...
Famous quotes containing the word functions:
“When Western people train the mind, the focus is generally on the left hemisphere of the cortex, which is the portion of the brain that is concerned with words and numbers. We enhance the logical, bounded, linear functions of the mind. In the East, exercises of this sort are for the purpose of getting in tune with the unconsciousto get rid of boundaries, not to create them.”
—Edward T. Hall (b. 1914)
“The mind is a finer body, and resumes its functions of feeding, digesting, absorbing, excluding, and generating, in a new and ethereal element. Here, in the brain, is all the process of alimentation repeated, in the acquiring, comparing, digesting, and assimilating of experience. Here again is the mystery of generation repeated.”
—Ralph Waldo Emerson (18031882)
“Those things which now most engage the attention of men, as politics and the daily routine, are, it is true, vital functions of human society, but should be unconsciously performed, like the corresponding functions of the physical body.”
—Henry David Thoreau (18171862)