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Transcript of touch
TOUCH
Smital Patel
Alexa Paganini
Nathan Penn
Period 3
TOUCH SENSORY STRUCTURES
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
TOUCH SENSORY STRUCTURES
TYPES OF RECEPTORSTypes of Receptors Stimulated by…
Chemoreceptors Changes in chemical concentration of
substances
Pain Receptors Tissue damage
Thermoreceptors Changes in temperature
Machanoreceptor Changes in pressure or movement
Photoreceptors Light energy
PATHWAY OF SENSORY INFORMATION
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.
DIAGRAM OF PATHWAY
DISORDERS
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.
DISORDERS
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.