An Intro. To Biopsychology The Nervous System

Neuron Simplest nerve cell

Parts of Neuron Body Dendrites (hairy fibers that receive info.)

Axons Long and skinny Send messages to the cell body, other neurons , muscles and glands

W/out it no muscle control Myelin Sheath: insulates axons on some neurons to increase their speed. Neural speed= 2 mi/hr to 200 m/hr W/out it no muscle control

Neural Reaction Pressure, Heat, Light, Chemicals Cells are stimulated + send a charge down the axon= Action Potential Action Potential Animation Action Potential Animation

Synaptic Gap The space btwn. 2 neurons

Neurotransmitters Chemical messengers that got from one neuron to another When they attach to a neuron they release ions into it

Some Neurotransmitters Acetycholine (Ach) Effects learning + memory Is located where neurons meet the bones Causes contraction Can be used in botox (no contracting=no wrinkles..but botox can be creepy) Alzheimers patients have less Ach

Dopamine (r) Influences mvmnt, learning, attention & emotion Without enough Dopamine you have tremors Parkinsons patients & schizophrenics have too little

Serotonin Effects modd, hunger, sleep, arousal

Norepinephrine Effects alertness, arousal, & depression

GABA Inhibits action Too little causes seizures, tremor +/ insomnia

GABA Pathways in the Brain

Glutamate Effects memory & excitement Too much= Seizure or migraines Ex. MSG

Endorphins Natural Opiate Release during vigorous exercise or pain Explains running high & ability to function thru serious pain (ex. Combat wounds) Taking external opiates causes the body to stop making endorphins=withdrawal symptoms