TheNervous System

What does it do?

Is the communication and control system of the body.• Receives information.

• Responds to information.• stimulus

• response

• Maintains homeostasis.

Parts of the Nervous System Central Nervous

System (CNS)• Brain - main control of

the body - directs and coordinates all body processes, thoughts, behaviors and emotions

• Spinal Cord - bundle of nerves inside the vertebra that carries messages to and from the brain.

Peripheral Nervous System (PNS)• all other nerves in the

body

Autonomic Nervous System• Controls the body’s

automatic function

What’s a neuron?

A message carrying cell. Carries messages to and from the brain

and spinal cord. Parts of a neuron:

• Dendrites- receive impulses from other neurons and send them to the cell body.

• Axons- carry impulses away from the cell body.

• Synapse- small space between two neurons.

Kinds of neurons

Sensory Neurons - pick up stimulus from internal or external environment and converts into a nerve impulse.

Interneuron - carries nerve impulses from one neuron to another

Motor neuron - sends an impulse to a muscle

What’s a nerve impulse?

The message that a neuron carries. It is the signal that is passing through

a neuron.

What’s a reflex?

Responses to changes in the environment.• Automatic

• Fast

Help maintain homeostasis.• Allow rapid response to changes.

• Involve spinal cord and nerves.