Nervous System Overview

Divided into Two Parts: Central (CNS) Peripheral (PNS)

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

Hippocampus Stores and processes memories Helps find memories Affects emotions

Cerebellum Coordinates –Most muscles –Movement –Learned skills

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

Brain Stem Coordinates –Heartbeat –Breathing –Digestion –Swallowing –Blinking

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

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

Neurons Nerve Cells Parts –Soma –Dendrites –Axon Carry messages –Called impulses

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

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 Systems Simple, slow moving animals like hydra have neurons arranged in a network of bipolar neurons called a nerve net.