Divisions of the
Nervous System
2 main divisions of the
nervous system

Central Nervous System



Brain
Spinal Cord
Peripheral Nervous System:


Autonomic Nervous System
Somatic Nervous System
Central Nervous System

The control center of the body.

Our brain controls most of the functions in our
bodies.
CENTRAL NERVOUS SYSTEM

The spinal cord is a thick column of nerve tissue
that links the brain to most of the body’s nerves.

Most impulses travel through the spinal cord to
get to the brain.
THE BRAIN

Consists of 100 billion neurons, all are
interneurons.

Each interneuron receives messages from 10,000
other sensory neurons!

Each interneuron sends a response reaction to
1,000 motor neurons!
THE BRAIN PROTECTION

What helps protect the
brain from injury?

1. Skull

2. Layers of connective
tissue

3. Fluid between the layers
of connective tissue
BRAIN STRUCTURES

Cerebrum

Cerebellum

Brainstem
CEREBRUM
Largest part of the brain.


Where learning, intelligence,
judgments occur.

Interprets input from the
senses.

Controls voluntary activities.

Shapes your attitudes,
emotions & personality.
Divided into 2 halves:

1. Right Side of Cerebrum


Controls left side of body
Artistic/Creative Side
2. Left Side of Cerebrum


Controls right side of body
Mathematical side
CEREBELLUM

2nd largest part of the brain.

Physical coordination.


Coordinates muscle actions.
Maintains balance.
BRAIN STEM (MEDULLA)

Connects the brain to the spinal cord.

Controls involuntary actions.

EX: Regulates breathing and helps control
heartbeat.
Central Nervous System
__6. Coordinates the actions of
the muscles.
a. Cerebrum
__7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
__ 8. Interprets input from the
senses.
c. Brain Stem (medulla)
__ 9. Gives the body its sense of
balance.
__ 10. Carries out learning,
remembering, and making
judgments.
Central Nervous System
B 6. Coordinates the actions of
the muscles.
a. Cerebrum
__7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
__ 8. Interprets input from the
senses.
c. Brain Stem (medulla)
__ 9. Gives the body its sense of
balance.
__ 10. Carries out learning,
remembering, and making
judgments.
Central Nervous System
B 6. Coordinates the actions of
the muscles.
a. Cerebrum
C 7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
__ 8. Interprets input from the
senses.
c. Brain Stem (medulla)
__ 9. Gives the body its sense of
balance.
__ 10. Carries out learning,
remembering, and making
judgments.
Central Nervous System
B 6. Coordinates the actions of
the muscles.
a. Cerebrum
C 7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
A 8. Interprets input from the
senses.
c. Brain Stem (medulla)
__ 9. Gives the body its sense of
balance.
__ 10. Carries out learning,
remembering, and making
judgments.
Central Nervous System
B 6. Coordinates the actions of
the muscles.
a. Cerebrum
C 7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
A 8. Interprets input from the
senses.
c. Brain Stem (medulla)
B 9. Gives the body its sense of
balance.
__ 10. Carries out learning,
remembering, and making
judgments.
Central Nervous System
B 6. Coordinates the actions of
the muscles.
a. Cerebrum
C 7. Controls involuntary body
actions, such as breathing.
b. Cerebellum
A 8. Interprets input from the
senses.
c. Brain Stem (medulla)
B 9. Gives the body its sense of
balance.
A 10. Carries out learning,
remembering, and making
judgments.
SPINAL CORD

The spinal cord is a
bunch of nerve tissue
that are the link
between the brain and
the peripheral nervous
system (PNS).
SPINAL CORD PROTECTION
What protects the spinal
cord?
1.
2.
3.
Vertebrae column
Layers of connective
tissue
A watery fluid
PERIPHERAL NERVOUS SYSTEM
(PNS)

Made up of a
network of nerves
that branch out
from the Central
Nervous System
(CNS).
PERIPHERAL NERVOUS SYSTEM
PNS is divided into to groups.

Somatic Nervous System:



controls voluntary actions
EX: Tying a shoe, eating with a fork
Autonomic Nervous System:



controls involuntary actions
EX: Digestion of food, expansion and relaxation of
blood vessels.
AUTONOMIC
SOMATIC
Nervous System Injuries

19. A bruiselike injury of the brain is called
a(an) ____________.
Nervous System Injuries

19. A bruiselike injury of the brain is called
a(an) concussion.
20. What can you do to decrease your
chances of getting a brain injury?

Wear a helmet…
21. What happens when the spinal cord
is cut or crushed?

All the nerve axons in the region are
damaged-so impulses cannot pass through
them causing loss of movement.
 Homework….
Worksheet
#102/103