Nervous System06/01/12

pages 159-160

Know: What are the 3 functions

of the nervous system?

Functions

Process

1. Receiving info – inside and outside body

2. Responding to info – reaction to stimulus (change/signal)

3. Maintaining homeostasis

Neurons (nerve cells) carry nerve

impulses (electrical or chemical

messages)

Process

Dendrite

Axon

Impulses begin in dendrite, move

toward cell body, then down axon.

Carries impulse toward cell body

Carries impulse away from cell body(Draw picture/label below)

Axons & Dendrites

Process Brain receives message and sends

impulses to muscles.

Impulses are passed from one nerve

to another or to an organ through

chemicals that jump the synapse (gap

between nerve cells)

Types

Reflex

1. Central – control center of body, brain and spinal cord

2. Peripheral – carries impulses between central nervous system and rest of body

- Somatic nervous system – controls voluntary actions (texting)

- Autonomic n.s. – controls involuntary actions (heart beat)

Automatic involuntary response to danger. Ex: your arm pulls back if you touch something hot

Evidence & SummaryEvidence: TB page 633, Draw, label, color