Ch. 12 somatic & sensory

Somatosensory System Sensations

Pain (nociception), touch, temperature, body position (proprioception)

Nociceptive

Stimulus originates outside nervous system

Ex. Falling twisting your ankle playing beach volley ball

Neurogenic or neuropathic

Stimulus originates within nervous system

Ex. (MS patients)

Conduction of Pain Sensation

Stimulation of free nerve endings
Chemical, mechanical, or thermal stimuli

l

Transduction of noxious stimuli into a nerve impulse
l

Transmission from tissues to CNS
Type A (delta) and C fibers, Induction of autonomic & reflex responses C fibers

Conduction of pain sensation Modulation

Substances released during
impulse transmission, Slow the rate of impulse
transmission

Perception

Sensory (somatosensory cortex) and emotional (limbic system) involvement