Smital Patel Alexa Paganini Nathan Penn Period 3

 Free Nerve Endings: free ends extend between epithelial cells; associated with sensations of touch and pressure  Meissner’s Corpuscles: small, flattened masses of connective tissue cells; respond to the motion of objects that barely contact the skin by interpreting impulses  Pacinian Corpuscles: large structures composed of connective tissue fibers and cells; respond to heavy pressure

Types of ReceptorsStimulated by… ChemoreceptorsChanges in chemical concentration of substances Pain ReceptorsTissue damage ThermoreceptorsChanges in temperature MachanoreceptorChanges in pressure or movement PhotoreceptorsLight energy

 Receptors are distributed throughout the skin and internal tissues, except for that of the brain.  When stimulated, receptors send impulses to the central nervous system.  These impulses are processed in the gray matter of the spinal cord before they ascend to the brain.  Within the brain, impulses pass through the reticular formation before being conducted to the cerebral cortex.  The cerebral cortex then interprets the source of the impulses and determines how to react.

 Giaccai type acroosteolysis AKA Hereditary Sensory Neuropathy, Type 2 (HSN2):  Rare genetic disorder that usually begins in childhood.  Loss of feeling, especially in the hands and feet.  Loss of sensation often leads to neglect of wounds.  Could result in amputation in extreme cases.

 Tactile Agnosia:  Subtle and nondisabling disorder.  Results from lesions, tumors, or damage to the mesial temporal, relosplenial, or mesial occipital cortices of the brain.  Causes an individual to be unable to recognize objects by touch.  However, other senses can be used to identify objects without difficulty.