PSC 131 Lecture Notes - Lecture 15: Lamellar Corpuscle, Michael Merzenich, Bulbous Corpuscle
Document Summary
Lecture 15 touch & pain (may 31, 2017) Skin is the heaviest organ in the body. Somatosensation a collective term for sensory signals from the body. Touch receptors embedded in outer layer (epidermis) and underlying layer (dermis) of the skin. Tactile mechanoreceptors respond to mechanical stimulation (pressure, vibration, or movement: touch receptors can be categorized by three criteria: Type of stimulation to which the receptor responds: size of the receptive field (small, big) iii. Surface receptors have smaller receptive fields than deep receptors. Rate of adaptation (fast vs slow) b. c. Slow adaptation; large receptive field; stretching of skin during grasping; larger receptor fields b. sensitive to continuous pressure. Pacinian corpuscles (fa ii) fast adaptation (sensitive to on/off stimuli), large receptive field; sense rapid vibrations and fine texture (buzz) Feeling shape of key in hand (merkel cell complex, sa i) Shaping your fingers grasp the key (ruffini endings, sa ii) b.
