PSYB51H3 Lecture Notes - Lecture 11: Ventral Posterior Nucleus, Lamellar Corpuscle, Dorsal Root Ganglion
Document Summary
Touch: mechanical displacements and other physical impacts on the skin. Somatosensation: collective term for sensory signals from the body. E(cid:448)e(cid:374) though you"re tappi(cid:374)g at spe(cid:272)ifi(cid:272) pla(cid:272)e (cid:449)/ gaps i(cid:374) (cid:271)et(cid:449)ee(cid:374), (cid:449)e te(cid:374)d to per(cid:272)ei(cid:448)e tappi(cid:374)g as though it"s spa(cid:272)ed apart i(cid:374) so(cid:373)e patter(cid:374) 2 separate locations stimulated multiple times in quick succession feels like a bunny, hopping across the skin between the 2 locations. Touch receptors: embedded in the outer layer (epidermis) and underlying (dermis) There are multiple types of touch receptors. Touch receptors (and other somatosensory receptors) have 3 attributes: Mechanoreceptors: respond to mechanical stimulation or pressure. There are 4 mechanoreceptors: [organized top bottom: meissner corpuscles (fa i) skin slip, low frequency vibrations (3-40 hz) Small receptive field, fast adapting: merkel cell neurite complexes (sa i) fine spatial details, textures, patterns (braille); sustained pressure, spatial deformations (<5 hz) Small receptive field, slow adapting: ruffini endings (sa ii) lateral stretch (grasping), hand shape; low sensitivity to vibrations.
