MCELLBI C61 Chapter Notes - Chapter 16: Cerebral Cortex, Frontal Lobe, Apraxia
19 Nov 2016
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Dendrites of somatosensory neurons terminate in top skin layers. Membranes of these nerve fibers have receptor proteins responding to touch/poke/temperature changes. Some nerve fibers have free endings in skins top layers. Some endings closely related to hair follicles. Some fibers end in structures responding to pressure associated with touch. Merkels discs, pacininian corpuscles, meissner"s corpuscles, ruffini endings------- Receptors related to touch/poking presumed to be based on mechanically-gated ion channels. Maybe similar to inner ear hair cells that open as hairs bend receptors responsive to temperature change very same trp receptors described in ch. Wilder penfield discovery of ss body map canadian neurosurgeon wilder penfield (1891-1976) He electrically stimulated various cc regions during brain surgery. By stimulating/recording answers penfield characterized location of somatosensory cortex (ssc) in parietal lobe (pl) and was first to describe ss map of body. Primary ss cortex (s1) has topographic representation of ss space (body surface) (p. 188-190) Ss receives signals from contralateral (cl) side of body.
