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Divisions of theNervous System

Chapter 15-2

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en ra ervous

SystemCentral Nervous System consists of the brainand spinal cord

Central Nervous System is the control centerof the body

Brain- part of the CNS that controls mostfunctions in the body

Spinal cord- thickcolumn of nerve tissuethat links the brain tomost of the nerves inthe peripheral nervoussystemMost impulses from theperipheral nervous

system travel throughthe spinal cord to the

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The Structure andFunctions of theBrain

Braincontainsabout 100billioninterneurons3 layers of connectivetissuesurround thebrainSpacebetween theoutermostand middlelayer is filled

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Cerebrum

3 main regions of thebrain: cerebrum,cerebellum, andbrainstem

Cerebrum- interpretsinput from the senses,controls the movementof skeletal muscles, and carries out complexmental processes suchas learning

Right side of thecerebrum controlsmuscles on the left side of the body

Left side of the cerebrumcontrols right side of the body

Right side of cerebrumassociated withcreativit and artistic

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Cerebellum andBrainstem

Cerebellum-coordinates theactions of yourmuscles andhelps you keepyour balance

Brainstem-

between thecerebellum andspinal cord;controls yourbody’sinvoluntary

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Spinal Cord

Vertebral columnsurrounds andprotects the spinal

cordSpinal cord linksyour brain andperipheral nervoussystem

Connective tissuesurrounding brainalso cover spinalcolumn

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Function of thePeripheral Nervous System

PNS consists of anetwork of nervesthat branch out

from the CNS andfunction toconnect it to therest of the body

Impulses travel toand from the CNSon a spinal nerve

Spinal nerves

contain axons of both sensory and

Somatic NervousSystem- controlsvoluntary actions

such as using afork

Autonomic nervoussystem- controls

involuntaryactions such ascontractions of the smooth

muscles thatadjust the

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Safety and the NervousSystem

Concussions and spinal cord injuriescan injure the nervous system

Concussion- bruise-like injury of thebrain

Helmets help prevent concussionsSpinal cord injuries occur when the

spinal cord is cut or crushed; causesimpulses to be unable to pass to thebrain from the body

Paralysis can result from spinal cord

injury

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Review

What is the function of the centralnervous system? Which organs are partof this system?

What is the peripheral nervous systemand what is its function?

Explain what a reflex is. How do reflexeshelp protect the body from injury?

What symptoms might indicate that a

person’s cerebellum has been injured?