1. Lesson 8.1 Outline of Nervous System
Functions:
Communication
Coordination
Control
Gathering information

2. Differences between
human and animal NS:
1. Language
2. Judgment
3. Problem solving
4. Creativeness
5. Passing along heritage

3. Neurobiologist –
biologist who studies
the nervous system.
Neurologist – physician
who specializes in
disorders of the NS.

4. Two Divisions of NS:
1. Central nervous system
(CNS) – brain and spinal
cord/nerves

6. Two Divisions of NS:
1. Central nervous system (CNS) – brain and spinal cord/nerves
2. Peripheral nervous system
(PNS)
nerves that branch from the
CNS.

9. CNS Composed of:
1. Brain
•protected by cranium
•has high levels thought
•major organ of NS
•Message center
•Uses info to formulate ideas
•Makes decisions
•Communicates to body

10. CNS Composed of:
1. Brain
2. Spinal Cord
Thick bundle nerve fibers
within spinal cavity
How brain communicates
with most of body
Ends at first lumbar

11. PNS Composed of:
1. Cranial nerves
Nerves that come from brain
12 pairs
Branch from brain stem
Transmits messages from/to
eyes, ears, mouth, face and
scalp

13. PNS Composed of:
1. Cranial nerves
2. Spinal Nerves
Nerves that come from spinal
cord
31 pairs
Transmit signals to and from
the rest of the body

15. Brain and spinal cord covered
by a triple layer of protective
tissue called Meninges.

16. Cerebrospinal fluid –
bathes the brain and
runs through fibers of
middle meninge to
cushion brain.

17. Nerves are made of
bundles of nerve cells
called neurons.

18. Three parts of neurons
1. cell body
• contains the nucleus, found only
in spinal cord and brain.

19. Three parts of neurons
1. cell body
A mass of cell bodies is called a
ganglion.
Large mass of ganglion called a
plexus.
Nerve center – plexus that has a
certain function.

21. Three parts of neurons
1. cell body
2. dendrites – short, branched
extensions of cell body that
receive nerve impulses and
conduct them toward the cell
body.

22. Three parts of neurons
1. cell body
2. dendrites
3. axon – one long extension
which carries impulses to
other neurons or cells

23. Nerve
impulses travel
from the dendrite
to cell body to
axon.
Axon branches
at terminal end.

24. GLIAL CELLS – also found
in the nervous system
are cells that SUPPORT
AND INSULATE not
functional.

25. Gray Matter vs. White Matter
Gray matter – within spinal cord
and brain composed of cell
bodies not wrapped by myelin
White matter – made up of
dendrites and axons wrapped in
myelin.

27. Myelin
•An insulating material that forms
a layer, the myelin sheath, usually
around only the axon of a neuron.
•It is essential for the proper
functioning of the NS.
•Myelin is an outgrowth of a glial
cell.

28. 3 Types of neurons:
1. Sensory neurons – transmit
from sense organs to CNS
2. Motor neurons – transmit from
CNS to other part of body
3. Interneurons – neurons within
the CNS that connect sensory and
motor neurons with each other.

29. Sciatic Nerve – one of the
longest nerves of the body.
Branches from spinal cord of
lower back and goes to the
leg.

31. PNS Types of Nerve fibers:
1. Mixed – both sensory and
motor neurons. Go from
sense organ to spinal cord
and send message back.
2. Sensory
3. Motor

32. Divisions of the PNS
1. Somatic – skeletal muscle
control
2. Autonomic – responsible
for all routine body activities
freeing the mind to
concentrate on biology class.

33. Two divisions ANS:
Sympathetic –stimulates when
danger, stress, or active
ex. Increases heart rate when
scared
Parasympathetic – stimulates
when at rest, or brings things back
to normal. Ex. Decreases heart rate
after scare is over.