Transcript Nervous System

Nervous System
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Use your gray matter!
Central Nervous System
Communication and
coordination system
of the body
 Seat of intellect and
reasoning
 Consists of the brain,
spinal cord, and
nerves.

Neuron
Nerve Cell
 Neuron function:
transmit message
from one cell to the
next.

Dendrites
Nerve cell processes
that carry impulse to
cell body
 May be one or many

Axon
Carries impulse
away from cell
body
Only one on a
neuron

Neurilemma (Myelin
Sheath)
Covering that speeds
up the nerve impulse
along the axon
 Myelin is a fatty
substance that
protects the axon
 Synapse- space
between neurons,
messages go from
one cell to the next.

Nerve Impulse

A stimulus creates an
impulse. → the
impulse travels into
the neuron on the
dendrite (s) and out
on the axon. At the
end of the axon, a
neurotransmitter is
released that carries
the impulse across the
synapse to the next
dendrite.
Different Neurons
Sensory Neurons Motor Neurons
AfferentEfferent
Associative
Neurons
Interneurons
Emerge from the
skin or sense
organs, carry
impulses to spinal
cord and brain
Carry impulses
from sensory
neurons to motor
neurons
Carry messages
from the brain
and spinal cord
to muscles and
glands
Divisions of the Nervous
System
Central Nervous Peripheral
System
Nervous system
Autonomic
Nervous System
Brain and
spinal cord
Includes peripheral
nerves and ganglia,
supplies heart muscle,
smooth muscle and
secretory glands,
involuntary action
Cranial nerves
and Spinal
nerves
The Brain-central nervous system
3 lb mass of soft nervous
tissue
 100 billion neurons
 Protected by the skull,
three membranes called
meninges, and
cerebrospinal fluid
 Adequate blood supply is
needed, brain tissue will
die in 4-8 min. without O2
 Divided into 4 major
parts: cerebrum,
diencephalon,
cerebellum, brain stem


Draw a picture of two
dendrites. Using the
bubble map show what
happens when a
stimulus creates an
impulse. Please use
color.


Color pictures on
bubble map and write
in color also.
Make sure your
drawing covers the
entire page. Do not
copy from anyone!
Questions for 3.01 BM one