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Delivers somatic and visceral sensory information to the CNS.
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Sensation: information gathered by a sensory receptor

◦ Processing in the thalamus:
 Determines whether you perceive sensation as fine touch, as pressure, or as vibration
Sensory homunculus: visualizes the connection between different body parts and areas in brain hemispheres.

◦ Provides voluntary control over skeletal muscles
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Homunculus provides indication of how much fine motor control available hands, face, and tongue are capable of varied and complex movements

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Subconscious control over skeletal muscle tone (neck, trunk and limbs)
* Controls responses to equilibrium sensations
(balance)

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Somatic Nervous System (SNS)
◦ Operates under conscious control
◦ SNS controls skeletal muscles
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Autonomic Nervous System (ANS)
◦ Operates without conscious instruction
◦ ANS controls visceral effectors
◦ Coordinates system functions: cardiovascular, respiratory, digestive, urinary, reproductive

 Sympathetic division:
 increases alertness, metabolic rate, and muscular abilities
 "fight or flight"
 Parasympathetic division:
 reduces metabolic rate, conserves energy and promotes digestion
 “rest and digest”
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