NROC64H3 Chapter Notes - Chapter 4: Lamellar Corpuscle, Glabrousness, Posterior Grey Column
Document Summary
Cutaneous receptors use bipolar cells as afferent fibres. The bodies of the bipolar cells lie in the dorsal root ganglia. Their axons run from sensory ends in skin to terminals in cns. Dermatomes: regions projecting to each dorsal root. Each point of body surface connected to 2 dorsal roots; for overlap. Fibres from viscera found in para and symp of ans. Peripheral sympathetic nerves --> sympathetic chain --> drg --> Parasympathetic afferents of sacral region --> drg. Cranial afferents cell bodies (vagus) are in the inferior ganglion (nodose) Peripheral fibres end as naked or encapsulations. Pacinian corpuscle: lies deep in dermis, big: meissner corpuscle, merkel disc, ruffini ending (similar to golgi tendon organ in muscle) Encapsulated ends found in glabrous (hairless) skin. Naked ends found in hairy skin but also in glabrous skin (dermis) Glabrous skin: naked endings have small afferent fibres, can be unmyelinated. All of the above are mechanoreceptors; give brain sensitive and directional info about hair.
