Functions
Stretch-activated ion channels are of use in the initial formation of an action potential from a mechanical stimulus, for example by the mechanoreceptors in an animal's vibrissae (whiskers).
Afferent nerve fibers responsible for sensory stimulus detection and feedback are especially sensitive to stimulation. This results from the specialized mechanoreceptor cells that are superimposed upon the afferent nerve fibers. Stretch-activated ion channels are located on these mechanoreceptor cells and serve to lower the action potential threshold, thus making the afferent nerves more sensitive to stimulation. Afferent nerve endings without mechanoreceptor cells are called free nerve endings. They are less sensitive than the encapsulated afferent fibers and generally function in the perception of pain.
Stretch-activated ion channels are responsible for many bodily functions in mammals. In the skin they are responsible for sensing vibration, pressure sensation, stretch, touch, and light touch. They are expressed in sensory modalities including taste, hearing, smell, heat sensation, volume control, and vision. They can also regulate internal functions of our body including, but not limited to, osmotic pressure in cells, blood pressure in veins and arteries, micturition, and heart contractility. In addition to these functionalities, stretch-activated ion channels have also been found to be involved with balance and proprioceptive sensation.
Read more about this topic: Stretch-activated Ion Channel
Famous quotes containing the word functions:
“Adolescents, for all their self-involvement, are emerging from the self-centeredness of childhood. Their perception of other people has more depth. They are better equipped at appreciating others’ reasons for action, or the basis of others’ emotions. But this maturity functions in a piecemeal fashion. They show more understanding of their friends, but not of their teachers.”
—Terri Apter (20th century)
“If photography is allowed to stand in for art in some of its functions it will soon supplant or corrupt it completely thanks to the natural support it will find in the stupidity of the multitude. It must return to its real task, which is to be the servant of the sciences and the arts, but the very humble servant, like printing and shorthand which have neither created nor supplanted literature.”
—Charles Baudelaire (1821–1867)
“Nobody is so constituted as to be able to live everywhere and anywhere; and he who has great duties to perform, which lay claim to all his strength, has, in this respect, a very limited choice. The influence of climate upon the bodily functions ... extends so far, that a blunder in the choice of locality and climate is able not only to alienate a man from his actual duty, but also to withhold it from him altogether, so that he never even comes face to face with it.”
—Friedrich Nietzsche (1844–1900)