Chap 2 mdterm

Central Nervous System

Includes the brain and spinal cord

Peripheral Nervous System

Allows all parts of the body to transmit messages to the spinal and brain

Somatic Division

Transmits Sensory information and controls voluntary muscle movements

Autonomic Division

Controls “automatic” functions in body like breathing, heart rate, etc.

Sympathetic Division

Activated when stress

Parasympathetic Division

Brings body back to homeostasis; calm

Glial

Located in central nervous system; housekeeping/ support system in the brain

Neurons

cells specialized to process, send and receive information

Dendrites

receives the incoming message

Soma

cell body/ rests at a slightly negative charge

Axon

carries/sends the electrical impulse

Myelin Sheath

fatty insulation around the axon that speeds & smooths transmissions

Axon Terminals

Stores the neurotransmitters waiting to be released

Synapse

Space formed between neurons to form neural pathways

Sensory Neurons

Carries sensory info into the brain

Motor Neurons

Exit the brain'; carries info out of the brainIn

Resting Potential

Neuron at rest has a slightly negative charge

Depolarization

As dendrites receive messages the charge shifts from slightly negative to slightly positive

Action Potential

Electrical Signal Sent down the axon-towards the waiting axon terminal buttons

All or nothing principal

A neuron either fires or it does not

Refractory Period

Once a neuron fires it cannot immediately refire