NRSC 277 Chapter Notes - Chapter 12: Glabrousness, Posterior Grey Column, Lamellar Corpuscle
Document Summary
Somatic sensation - enables body to feel, and to know what its parts are doing. 2 unique differences from other sensory systems: Receptors are distributed throughout the body; no specialized locations. Group of multiple senses, not one; responds to various stimuli. Hairy skin and glabrous skin (hairless) - 2 types of skin; back&front of hand. Epidermis (outer layer) and dermis (inner layer) Unmyelinated axon branches that are sensitive to stretching, bending, pressure or vibration. Pacinian corpuscle - lies deep within the dermis; largest and best studied. Ruffini"s endings - hairy and glabrous skin; slightly smaller. Meissner"s corpuscles - ridges of glabrous skin (raised parts of fingerprint); 1/10th size of p. c. Merkel"s disks - nerve terminal and merkel cell; in epidermis. Merkel cell - flattened, non-neural epithelial cell. Krause end bulbs - border regions of dry skin and mucous membrane. Supplied by thinly myelinated and unmyelinated fibers that terminate as free nerve endings. Mechanoreceptors: in the wall of hollow organs.
