PSYC 371 Lecture Notes - Lamellar Corpuscle, Dorsal Root Ganglion, Glabrousness
Document Summary
Somatic sensation enables our body to feel, to ache, to chill, and to know what its parts are doing. It is sensitive to many kinds of stimuli. The central nervous system interprets the activity of the vast receptor array and uses its to generate coherent perceptions. There are two major types of skin: hairy and glabrous (hairless). Skin has an outer layer, the epidermis, and an inner layer, the dermis. Skin performs an essential protective function, and it prevents the evaporation of body fluids into the dry environment we live in. Most of the sensory receptors in the somatic sensory system are mechanoreceptors, which are sensitive to physical distortion such as bending or stretching. Pressure in the heart and blood vessels. Stretching of the digestive organs and urinary bladder force against the teeth. Each mechanoreceptor contains unmyelinated axon branches which have mechanosensitive ion channels whose gating depends on stretching or changes in tension of the surrounding membrane.