NROC64H3 Chapter Notes - Chapter 4: Pyramidal Cell, Red Blood Cell, List Of Thalamic Nuclei
Document Summary
Skin is the largest sensory organ, there are 2 types: hairy and glabrous. The outer layer is known as the epidermis and the inner layer is the dermis. Overall, skin functions for protection, prevention of evaporation, and direct contact with the world: mechanoreceptors: sensory receptors of the somatic sensory system that detect distortion such as bending or stretching. These are used to monitor skin contact, blood pressure in the heart/blood vessels, stretching of digestive organs and the bladder, force against teeth etc. The axon branches are unmyelinated with mechanosensitive ion channels. There are 4 main types: pacinian corpuscle: largest receptor, found in the dermis, large receptive fields, quick response to stimulus and stop firing with continuous stimulus (rapid adapting). These are sensitive to vibrations at 200-300hz: ruffini endings: smaller than pacinian corpuscles, found in hairy or glabrous skin, large receptive fields, generate a sustained response during long stimulus (slow adapting).