HOW DOES THE
NERVOUS SYSTEM
WORK?
FUNCTIONS OF THE NERVOUS SYSTEM
Receives
the body
information from inside and outside of
Directs
the way the body responds to
information.
Helps
maintain homeostasis
Stimulus:
change or signal in the environment
causing a reaction.
Response:
Reaction to stimulus
Neuron
Neuron:
body
= nerve cell
carries nerve impulses through the
PARTS OF THE NEURON
Axon:
carries impulses away from the cell body
Dendrites:
cell body.
carry impulses toward the neuron’s
PARTS OF NEURON’S CONT.
Synapse:
junction where one neuron can
transfer an impulse to another structure
Nerve
impulses must cross the gaps between
the axon and next structure in order for the
impulse to be carried
Axon
tips release chemicals that carry the
impulses across the gap.
THREE KINDS OF NEURONS
1.
2.
3.
Sensory Neuron: picks up stimuli
from the internal or external
environment.
Interneuron: carries nerve
impulses from one neuron to
another
Motor Neuron: sends impulse to
muscle or gland – then muscle
or gland reacts.