THE NERVOUS SYSTEM

THE NERVOUS SYSTEM


THE NERVOUS SYSTEM is made up of 2 parts
● Central Nervous System (CNS!!!)
● Peripheral Nervous System (PNS)

Central Nervous System is also just 2 parts:
● Brain
● Spinal Cord
Makes sense because the brain and spinal cord are located at the CENTER of your body.
Your brain is in the CENTER of your head and the spinal cord runs down the CENTER
of your body. So, CENTRAL Nervous System.


Peripheral Nervous System
● Everything in the nervous system outside brain and spinal cord (CNS) that
relays info to and from brain
● Made up of neurons called long Axons and Dendrites. (A and D like ADD and
that rhymes with P, so they go with the P of the Peripheral Nervous System)
● Think of Perry the Platypus, as in Peri-pheral
● It also has 2 parts:
○ SOMATIC (VOLUNTARY) - Remember that SOME actors volunteer
their time. SOM-ATIC IS VOLUNTARY. Somatic system controls
actions you can control, like moving your muscles.
○ (Autonomic !) AUTONOMIC system (INVOLUNTARY) so it controls
heart rate, breathing, digestion--stuff you don’t control voluntarily
because it’s like on auto-pilot.

AUTONOMIC SYSTEM (INVOLUNTARY -happens without you thinking about
it!) also has 2 parts:
○ Sympathetic Division and
○ Parasympathic Division

SYMPATHETIC Division
● Responds to STRESS or your “fight or flight” response
● S for Sympathetic or S for Stress