16 Somatosensory Receptors

No work in long term but are slowly conducting but

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Unformatted text preview: ork in long-term but are slowly conducting BUT efferents are fast-conducting - Length restoration eventually comes after sustained contraction Somatosensory Receptors October 20, 2010 8 Group II & III Proprioceptors: Joint receptors - Attach to capsule enveloping joint - Golgi-Mazzoni corpuscles (paciniform) respond to orthogonal forces - Ruffini endings respond to capsule strain (tangential forces: extending joint) Type 2: Thermoreceptors - Location: free nerve endings in skin - Warm: group C; respond to skin temps from 25-45C (>45C: noxious!) - Cool: group A; respond to skin temps from 10-28C (<10C: afferents anesthetized) - Slowly adapting but strong phasic component - Like Ia muscle spindle: strong dynamic component - No specialized capsules around them: no assoc cells at terminals = free nerve endings - True also for nociceptors: histologically, they look the same! Or look for... - All have receptor proteins `TRP' (transient receptor potential) cation channels 9 4 of 5 Somatosensory Receptors October 20, 2 PSL302Y: Lecture 15, by Prof. MacKay# 40C 34C Wed., Oct.20, 2010 Thermoreceptors: response Skin Temperature - Warm receptors respond to skin T warm - Strong phasic component (respond to rate receptor of change) cold Somatosensory Receptors receptor - Also sustained asOctober 20, 2010 T maintained long as - Cold receptor silent - Warm receptors fall into group C b/c unmyelinated, S diam = slow conducting - Cool skin down: phasic burst in cool receptor warm - Cool receptors fall into group A b/c cold myelinated, S diam = quickly conducting - Must respond to cool stimuli more quickly b/c we're warm-blooded creatures - Dynamic range broader than static range of receptors 40C Skin Temperature warm recept...
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This note was uploaded on 03/27/2012 for the course PSL PSL300 taught by Professor Mackayfrench during the Fall '11 term at University of Toronto- Toronto.

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