nervous system overview. divided into two parts: central (cns) peripheral (pns)

Nervous System

Overview

Divided into Two Parts:

• Central (CNS)

• Peripheral (PNS)

http://www.morphonix.com

Central Nervous System

• Brain

• Spinal cord

Brain

• Cerebrum

• Cerebellum

• Brain stem

Cerebrum Cerebral Cortex

• Coordinates– Thinking and learning– Creativity– Five senses– Memory and emotion– Problem-solving– Decisions

http://www.morphonix.com

Hippocampus

• Stores and processes memories

• Helps find memories

• Affects emotions

http://www.morphonix.com

Cerebellum

• Coordinates– Most muscles– Movement– Learned skills

http://www.morphonix.com

Cerebellum

• Receives messages from most of the muscles in your body

• Communicates with the other parts of the brain

• Sends messages about movement and balance back to your body

http://www.morphonix.com

Brain Stem

• Coordinates– Heartbeat– Breathing– Digestion – Swallowing– Blinking

http://www.morphonix.com

Spinal Cord

• Bundle of nerves that carries messages between the brain and the rest of the body.

• Long tube of nerve tissue running from the brain down the length of the back inside of the spine

http://www.merck.com

http://www.paraquad.asn.au/

Peripheral Nervous System

• Somatic NS– Sensory nerves– Motor nerves– Messages between brain and body– CONTROLS VOLUNTARY MUSCLES

• Autonomic NS– Controls organs and some muscles– CONTROLS INVOLUNTARY MUSCLES

NeuronsNerve Cells

• Parts– Soma – Dendrites– Axon

• Carry messages– Called impulses

http://www.morphonix.com

Synapse

• Small space across which an impulse moves from an axon to the dendrites or cell body of another neuron

Stimulus-Response

• Stimulus (stimuli)– Anything that the body can react or respond

to• May be internal or external

• Response – the reaction to stimuli

http://www.bbc.co.uk

http://www.infovisual.info

Impulses are picked up by DENDRITES and travel down the AXON.

home.earthlink.net/~dayvdanls/IHP2.html

1. Stimuli comes into the brain through the five senses. The nerves that bring stimuli into the body are SENSORY neurons.

2. The impulse travels through INTERNEURONS.

3. When the impulse reaches the MOTOR neuron, the response occurs.

Diversity of Nervous SystemsSimple, slow moving animals like hydra have neurons arranged in a network of bipolar neurons called a nerve net.