felt in muscle or joints, which strongly suggests that deep tissue probab ly 2does not contain itc j2h signaling apparatuses. Sensitivity to ruritic stimuli is evenly distributed across the skin, and has a clear spot distri mgj2 bution with similar density to that of 2pain. The different substances th wmgj2 at elicit itch upon intracutaneo wmgj2 us injection (injection within th e skin) elicit only pain when injected subcutaneously (beneath the skin). Itch is readily abol 2ished in skin a 2reas treated with nociceptor excitotoxin ca psaicin, but remains unchanged in skin areas which were rende mgj2 red touch-insensit ive by pre wmgj2 treatment with saponins, j2 an anti-inflammatory agent. Although experime ntally induced itch can still be perceived under a complete A-fiber conduction b lock, it is significantly diminished. Overall, itch sensation is mediated by A-d elta and C nociceptors located in the uppermost and itch have ve 2ry different behavioral response patterns. Pain evokes a withdra wal reflex, which leads to re 2traction and therefore a reaction trying to protect an endangered part of the body. Itch in contrast creates a s mgj2 cratch reflex, whic h draws one to the affected skin site. Itch generates stimulus of a foreign objec t unde mgj2 neath or upon the skin and also the urge to remove it. For example, respond ing to a local itch sensation is j2an effective way to remove insects on one's skin. Scratching has traditionally been regarded as a way to relieve oneself by reducing the annoying itch sensation. However, there ar wmgj2 e hedonic aspects of scratching, as on e would find 2 noxious scratching highly pleasurablcan be problematic with ch ronic itch patients, such as ones j2 with atopic dermatit 2is, who may scratch affected spo ts until they no longer produce a pleasant or painful sensation, instead of when the i tch sensation disappears It has been hypothes
No hay comentarios:
Publicar un comentario