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I) NERVOUS SYSTEM = Master control
and communication system of the body. This system
works with the ENDOCRINE system to maintain and
regulate body HOMEOSTASIS (balance).
NERVOUS SYSTEM – Fast action, uses electrical
impulses. Changes by this system tend to be fast
but temporary.
ENDOCRINE SYSTEM – Slow action, uses
chemicals called HORMONES released into the
blood. Changes by this system tend to be slow but
long lasting.
The Nervous System has 3 Overlapping Functions:
1) SENSORY INPUT – sensory nerve receptors
collect information from both inside and outside
the body and send it to the Brain.
2) INTEGRATION – the brain processes the
sensory information, and makes decisions on
what must be done to maintain Homeostasis.
3) MOTOR OUTPUT – is a response or action
sent out to the body, from the brain. This usually
activates MUSCLES or GLANDS.
Sensory Input
Integration
Motor Output
Sensory Input  Integration  Motor Output
II) ORGANIZATION OF THE
NERVOUS SYSTEM
Nervous System
Central Nervous
System - CNS
Peripheral Nervous
System - PNS
Includes the Brain
and Spinal Cord
Includes the Cranial
and Spinal Nerves
Peripheral Nervous
System - PNS
Afferent (sensory)
Neurons
Conduct impulses from
Receptors towards the Brain
Efferent (motor)
Neurons
Transmit impulses away
from the brain to Effectors
Somatic Afferents
Somatic/Voluntary NS
Sensory Input from Skin,
Joints, Muscles, etc.
Motor Impulses from Brain
to Skeletal Muscles
Visceral Afferents
Sensory Input from Internal
Organs (heart, lungs, etc.)
Autonomic/Involuntary NS
Motor Impulses from Brain
to Internal Organs
Autonomic/Involuntary NS
Sympathetic Division
Parasympathetic Division
These 2 Divisions are ANTAGONISTIC to each
other, i.e. one speeds up the heart while another
one slows it down.
Basic Divisions
Afferents
CNS
Efferents
Which 2 branches of
the Nervous System
are MISSING from
this schematic?
***
***The 2 branches of
the Sensory division:
i.e. Somatic Afferents
and Visceral Afferents
Various
Pathways