HTHSCI 1G03 Lecture Notes - Lecture 9: Resource Acquisition Is Initialization, Afferent Nerve Fiber, Mechanoreceptor

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1G03
• Professor: Mike Wong

Document Summary

Receptors act as an interface between the external world and the brain: gives you awareness of the external world. Tactile receptors are activated by deformation of the skin: stretch-gated ion channels: when they open it allows cations to enter into receptor. Receptive field: area to which a neuron responds (ex: skin) Tactile mechanoreceptors of skin: merkel cells (corpuscle, meis(cid:374)(cid:374)e(cid:396)"s (cid:272)o(cid:396)pus(cid:272)le, pacinian corpuscle, ruffini corpuscle. ** receptors are innervated (attached) by afferents (attached to afferent nerve) Slowly adapting type-i, sai (merkel cell: static indentation. Slowly adapting type-ii, saii (ruffini corpuscle: lateral skin stretch. Rapidly adapti(cid:374)g type i, rai (cid:894)meiss(cid:374)e(cid:396)"s (cid:272)o(cid:396)pus(cid:272)le(cid:895: low-frequency vibrations (20-40hz) Rapidly adapting type-ii, raii (pacinian corpuscle: high frequency vibrations (1-300hz/second) Adaptation decrease in firing rate if stimulus is left on skin. Increase in slope indicates increased strength of stimulus. Not in skin, increasingly pressed into skin, taken off skin.