AP Psych Unit 1: 1.3 A-B Neurons, neurotransmitters

Neurons

the building blocks of the nervous system -> about 100 billion

Dendrites

branch-like projections that receive messages from other neurons and send them to the neuron

Soma

(cell body) structure made up of a nucleus that determines when the neuron has reached the threshold to fire

- also carries out basic metabolic functions of neurons

Axon

the "tail" of the neuron along which electrical signals are conducted

- passes messages away from cell body to other neurons, muscles or glands

Action Potentials

the electrical signals created by Axon -> carry messages to neutrons

- neuron is depolarized -> positive inside of cell for a moment

Myelin Sheath

white fatty substance that wraps axons -> insulates the axon and inscreases the speed ofthe action potential causing faster communication

-deterioration leads to motor/cognitive impairments

Nodes of Ranvier

notches in between myelin that allow exchange of sodium and potassium

Axon Terminals

knobs at the end of each axon that house chemical messengers called neurotransmitters (terminal buttons)

Synapse

the microscopic gap between terminal buttons of the presynaptic (sending) neuron and the dendrites of the postsynaptic (receiving) neuron

Glial cells

support cells that hold together the message - sending neurons and support their functioning -> provide nutrients

-"glue" neurons in place, form myelin around axons

Resting state

when a neuron is in resting state -> it has a slight negative charge due to presence of potassium ions

- it is positive outside of resting state

Firing threshold

the minimum level of membrane depolarization for a neuron or muscle cell to generate action potential

- level necessary for neuron to fire

Depolarization

positively charged sodium ions rush into the cell and potassium ions flow out temporarily leaving cell positively charged on inside

All-or-none response

a neuron can never fire "harder" or "stronger" because it either fires completely or not at all

Refractory period

the cell cannot fire again -> very brief (rest period)

- process of repolarization

Repolarization

each section of the axon needs to "push out" the positive sodium ions so the overall charge of the cell becomes negative again

Neurotransmitters

chemicals that allow for communication between neurons

- travel across synapes to bind to receptor sites

Vesicles (sacs)

sacs of terminal buttons (axon transmitters) at the end of the axon

Postsynaptic neuron

a nerve cell that receives neurons from another neuron (presynaptic)

Reuptake

the absorption by a presynaptic nerve ending of a neurotransmitter that it has secreted

Antagonist

dugs that inhibit or impede the action of a neurotransmitter

Agonist

drugs that inhace or amplify the action of a neurotransmitter

Lock and key

a specific neurotransmitter (key) binds only to its corresponding receptor protein (lock) on a postsynaptic neuron

Excitatory signal

excitatory neurotransmitter signals trigger action

- like a gas pedal

Inhibitory signal

inhibitory neurotransmitter signals depress action

- break pedals

Substance P

sends pain messages

- P is for pain "substance pain"

Serotonin

impacts mood, sleep, and appetite

- too much = maybe autism and anxiety

- too little = depression, OCD and eds

se"rot"onin -> rotten mood

Norepinephrine

involved in alertness and arousal of flight/fight - helps breathing, stimulates heart rate and constricts blood vessels

- too much = anxiety and panic attacks

- too little = depression

"Epi-pen"

Acetylcholine (ACH)

enables muscle action, influences memory-linked to alzheimers

"in order to hit an ACE in tennis you need good muscle control"

GABA

primary inhibitory neurotransmitter in the brain

- too little = insomnia

- too much = seizures

"Get A Brake Adjustment"

Glutamate

primary excitatory neurotransmitter in the brain

too much = seizures and migranes

"you get excited when you're glued to your mate"

Endorphins

block pain messages and linked to pleasure

- opiates are essentially artificial endorphins

ENDURE pain

Dopamine

associated with pleasurable emotions, reward pathways, learning and attention and movement

too little = Parkinson's disease

too much = schizophrena

"Dopey on Dopamine"