Section 1 Notes Organization of the Nervous System

1. D E F O R D
THE NERVOUS SYSTEM

2. ORGANIZATION
OF THE
NERVOUS SYSTEM
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3. NERVOUS SYSTEM OVERVIEW
• Master control and communication
system of the body
• Every thought, action, emotion is a
result of its activity
• Uses electrical impulses to interpret
and respond to what’s happening
inside and outside the body
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4. COMPONENTS
• Brain
• Spinal Cord
• Sensory Organs
• Nerves - connect these
components throughout
the body
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5. 3 PRIMARY FUNCTIONS
Stimuli
Sensory Input
Muscle
or
Gland
Motor Output
Integration1
2
3
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6. 3 PRIMARY FUNCTIONS
• Sensory Function: The nervous system monitors changes
and events occurring inside and outside the body. Such
changes are known as stimuli and the cells that monitor
them are receptors.
• Integrative Function: The nervous system processes and
interprets sensory input and decides if an action is
needed.
• Motor Function: The nervous system carries impulses
from the central nervous system to the effectors
(responsive structures such as muscles and glands). 6

7. 7

8. AN EXAMPLE
• Sensory Input: You’re driving
and see a red light ahead
• Integration: Your nervous
system integrates this
information as “red light means
stop”
• Motor Output: The muscles of
your right leg and foot move to
press the brake
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9. STRUCTURAL ORGANIZATION
• Central Nervous System
(CNS)
• Brain
• Spinal Cord
• Peripheral Nervous System
(PNS)
• Nerves outside the CNS
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10. CENTRAL NERVOUS SYSTEM
Personality
Creativity
Emotions Language
• Acts as the integration and
command center
• Takes in all conscious and
subconscious sensory information
• Makes decisions and initiates
responses to maintain homeostasis
• Stores memory and carries out
thought
Higher functions of the
central nervous system
include language, creativity,
emotions, and personality. 10

11. PERIPHERAL NERVOUS SYSTEM
• Made up of nerves that carry
messages back and forth between the
CNS and the muscles, organs, and
senses in the periphery of the body
(i.e., everything outside the CNS)
• Composed primarily of spinal nerves
(carry impulses to/from spinal cord)
and cranial nerves (carry impulses
to/from the brain)
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12. FUNCTIONAL ORGANIZATION
Two Subdivisions of the PNS:
• Sensory or Afferent Division
• Nerves that carry information TO
the CNS
• Motor or Efferent Division
• Nerves that carry information
FROM the CNS
CNS
S
e
n
s
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r
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M
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13. PNS FLOW CHART
Peripheral Nervous
System
Sensory
(Afferent)
Motor
(Efferent)
Sense
Organs
Somatic
(voluntary)
Autonomic
(involuntary)
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14. 2 SUBDIVISIONS OF MOTOR DIVISION
Somatic Division
• Allows conscious or
voluntary control of
skeletal muscles
• Includes reflexes
Autonomic Division
• Regulates events that are
automatic or involuntary
• Ex: smooth and cardiac
muscles and glands
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