Section 29-4Section 29-4“Nervous “Nervous SystemSystem””

Write everything that isWrite everything that is underlinedunderlined

29.4 Central and Peripheral Nervous Systems

KEY CONCEPT KEY CONCEPT The The centralcentral nervous system interprets nervous system interprets information, and the information, and the peripheralperipheral nervous nervous system gathers and transmits information.system gathers and transmits information.

29.4 Central and Peripheral Nervous Systems

Nervous?Nervous?• Nervous doesn’t mean afraid or Nervous doesn’t mean afraid or

uncomfortableuncomfortable

• It is just talking about the It is just talking about the nerves which are strands of nerves which are strands of neurons or nerve cellsneurons or nerve cells

• Think of it as Nerve-ousThink of it as Nerve-ous

29.4 Central and Peripheral Nervous Systems

How about How about interpretinterpret??

• Definition of Interpret: to explain the Definition of Interpret: to explain the meaning ofmeaning of

• The Central Nervous System processes The Central Nervous System processes and makes sense of the information it’s and makes sense of the information it’s given from your bodygiven from your body

• When someone pours water over your When someone pours water over your head how do you automatically know head how do you automatically know it’s water?it’s water?

• Your nervous system takes the info and Your nervous system takes the info and “tells” your brain what’s going on“tells” your brain what’s going on

29.4 Central and Peripheral Nervous Systems

Peripheral – hard to say isn’t it?Peripheral – hard to say isn’t it?

•Peripheral means Peripheral means “outer edge” “outer edge”

•Peripheral vision Peripheral vision means seeing stuff means seeing stuff behind youbehind you

29.4 Central and Peripheral Nervous Systems

I. The nervous system’s two parts work I. The nervous system’s two parts work togethertogether

• The Central Nervous System The Central Nervous System (CNS) includes the brain, (CNS) includes the brain, brain stem, and spinal cord.brain stem, and spinal cord.

• The Peripheral Nervous The Peripheral Nervous System (PNS) includes four System (PNS) includes four systems of nerves.systems of nerves.

29.4 Central and Peripheral Nervous Systems

• CNS CNS (Central (Central Nervous Nervous System)System)

• PNS PNS (Peripheral (Peripheral

Nervous Nervous System)System)

29.4 Central and Peripheral Nervous Systems

• The CNS and PNS pass The CNS and PNS pass signals between each othersignals between each other–Sensory receptor generates Sensory receptor generates

impulse impulse

–PNS passes impulse to CNSPNS passes impulse to CNS

–CNS interprets impulseCNS interprets impulse

–CNS passes impulse to PNSCNS passes impulse to PNS

–PNS stimulates a responsePNS stimulates a response

29.4 Central and Peripheral Nervous Systems

The CNS processes informationThe CNS processes information• The brain has three The brain has three

parts:parts:

– cerebrum controls cerebrum controls thought, movement, thought, movement, emotionemotion

– cerebellum allows for cerebellum allows for balancebalance

– brain stem controls brain stem controls basic life functionsbasic life functions

midbrainponspons

medulla oblongata

Brainstem

29.4 Central and Peripheral Nervous Systems

• The brain stem has three parts:The brain stem has three parts:

–midbrain controls some midbrain controls some reflexesreflexes

–pons regulates breathing pons regulates breathing

–medulla oblongata medulla oblongata controls heart function, controls heart function, swallowing, coughingswallowing, coughing

midbrain

medulla oblongata

pons

29.4 Central and Peripheral Nervous Systems

• The spinal cord controls reflexesThe spinal cord controls reflexes–sensory neuron sends sensory neuron sends

impulse to spinal cordimpulse to spinal cord

–spinal cord directs spinal cord directs impulse to motor impulse to motor neuron neuron

–does not involve the does not involve the brainbrain

interneuron

motor neurons

sensory neuron

29.4 Central and Peripheral Nervous Systems II. The PNS links the CNS to muscles and other II. The PNS links the CNS to muscles and other

organsorgans• The somatic nervous system The somatic nervous system

regulates voluntary movementsregulates voluntary movements

• The autonomic nervous system The autonomic nervous system controls involuntary, functionscontrols involuntary, functions– sympathetic nervous sympathetic nervous

system: “fight or flight”system: “fight or flight”

– parasympathetic nervous parasympathetic nervous system: calms the body, system: calms the body, conserves energy conserves energy