Download Divisions of the Nervous System

The Nervous System
 Nervous System – The
entire network of
neurons in the body.
 Includes:

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Central Nervous System
Peripheral Nervous
System
Their subdivisions
The Central Nervous System
 Central Nervous System –
The brain and spinal
cord.
 “Command Central”
The Central Nervous System
 The Brain
 Makes complex
decisions
 Coordinates body
functions
 Initiates our behaviors
 Responsible for
voluntary movements
The Central Nervous System
 The Spinal Cord
 Serves as a sort of neural
cable, connecting the
brain with parts of the
peripheral nervous
system extending into
the trunk and limbs.
 Does not connect the
brain to internal organs.
 Responsible for simple
reflexes.
The Peripheral Nervous System
 The Peripheral Nervous
System – Plays a
supportive role,
connecting the central
nervous system with the
rest of the body through
bundles of sensory and
motor axons, called
nerves.
The Peripheral Nervous System
 Carries messages
between the brain and:
 Sense Organs (eyes, ears,
etc.)
 Internal Organs
 Muscles
The Peripheral Nervous System
 The “Pick-up and
Delivery Service” for the
Central Nervous System.
Divisions of the PNS
 Somatic Nervous System
 Carries sensory
information to the
central nervous system.
 Sends voluntary
messages to the body’s
skeletal muscles.
Divisions of the PNS
 Autonomic Nervous
System
 Sends communication
between the central
nervous system and the
internal organs and
glands.

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
Regulate digestion
Respiration
Heart Rate
Arousal
Divisions of the PNS
 Sympathetic Division
 Part of the Autonomic
nervous system
 Sends messages to
internal organs and
glands that help us
respond to stressful and
emergency situations.
Divisions of the PNS
 Parasympathetic Division
 Part of the autonomic
nervous system
 Monitors the routine
operations of the
internal organs.
 Returns the body to
calmer functioning after
arousal by the
sympathetic division.
The Nervous System and Drugs
 Agonist – Drug or other chemical that enhances or
mimics the effects of neurotransmitters.
 Antagonist – Drug or other chemical that inhibits the
effects of neurotransmitters.