Types of Somatic and Special Senses Create a new folder in eBackpack: “Senses” Upload 10.02 Intro notes Upload 10.03 Structures and physiological events In the last unit you learned how impulses are transmitted throughout the body. In this unit we will study how the stimulus is received.

Senses Somatic Special Receptors found in the Receptors found in the head Skin Joints Muscles Viscera Eyes Nose Taste Buds Ears

Senses Somatic Special Sensitive to Sensitive to Light Odor Taste Sound Touch Pain Temperature Pressure

Sensory Receptors Definition Types Stimulated by Structures of the nervous system that gather information about the environment. Chemoreceptor Pain receptor Thermoreceptor Mechanoreceptor Photoreceptor Changes in chemical concentrations Tissue damage Changes in temperature Changes in pressure Changes in light

Focus on the Somatic Sense Recall The sense organs are: -skin -muscles -joints -viscera

Receptors and their function Physiology Mechanorecepors -Free nerve endings -Meissner’s corpuscles -Pacinian corpuscles -sense touch and pressure in epithelial tissue -respond to the motion of objects that barely touch the skin -respond to heavy pressure

Physiology Receptor Thermoreceptors Free nerve endings -sensitive to temperatures above 77 F -most sensitive to temperatures between 50and 68 F Thermoreceptors Free nerve endings -warm receptors -cold receptors Thermoreceptors role in maintaining homeostasis

Receptor Physiology Pain receptor Free nerve endings protect the body from further injury, sometimes trigger mechanoreceptors