psych 1.3a

Cell body (soma)

contains nucleus, life-support of neuron

Dendrites

receive incoming messages

Axon hillock

where signals are initiated

Axon

sends electrical impulses away from cell body

Myelin sheath

fatty tissue covering axons. insulates fiber of axon and helps speed up impulses.

Nodes of Ranvier

gaps in myelin where impulses jump (saltatory conduction)

Multiple sclerosis

is disorder where it starts to eat away at myelin sheath

Terminal buttons

release neurotransmitters. End of axon. Once neural impulse reaches it.

Glial cells

support, nourish, and protect neurons

Nucleus

cells life support system. Keeps cells alive

Neural firing

Neuron communicates with itself. Involves electrochemical message. 120 meters per second. All or none process.

Resting potential

neuron at rest, negatively charged inside

Threshold

minimum stimulation needed to trigger firing

Action potential (nerve impulse)

electrical signal traveling down axon also known as neural impulse 3 chemicals: chloride, sodium, potassium

All-or-none response

fires completely or not at all

Refractory period

recovery time when neuron can't fire again immediately. Action potential cannot occur until recharged, ionization starts going back to normal positive outside negative inside

Synapse

Space between neurons where neurotransmitters cross

Reuptake

neurotransmitters reabsorbed back into sending neuron

Acetylcholine (ACh)

muscle action, learning, memory. If there's too much involuntary movement. Ex: seizures/convulsions. Too little: alzheimers

Dopamine

movement, reward, emotion. Too much: schizophrenia. Helps with fluidity movement in dancers especially. Too little: parkinson's

Serotonin

mood, hunger, sleep, arousal. Too much: addiction. Low = depression

Norepinephrine

alertness, arousal, fight-or-flight (adrenaline) too much: manic schizophrenia. Too little: depression dont wanna do anything

GABA (gamma-aminobutyric acid)

major inhibitory neurotransmitter calms neural activity. Too much: sedation too little: seizures, insomnia, anxiety disorder

Glutamate

major excitatory neurotransmitter, memory too much: overstimulation, seizures, too little: listless

Endorphins

natural painkillers. Vigorous exercise. Too much: euphoria, dependence. If too much brain thinks you're producing enough so it stops producing, too little: causes pain pain more severe and causes stress

Substance P

involved in pain perception. Too much: chronic pain.