AP Psychology Key Terms 1.3-1.4 (copy)

Neuron

Nerve cell that sends signals.

Cell Body (Soma)

Holds nucleus, keeps cell alive.

Dendrites

Receive signals.

Axon

Sends signals away.

Myelin Sheath

Speeds signal travel.

Glial Cells

Support neurons.

Action Potential

Electrical signal down axon.

Threshold

Minimum stimulation to fire.

Refractory Period

Rest time after firing.

All-or-None Response

Fires fully or not at all.

Synapse

Gap between neurons.

Neurotransmitters

Chemical messengers.

Endorphins

Natural painkillers, boost pleasure.

Agonists

Mimic/enhance neurotransmitters.

Antagonists

Block neurotransmitters.

Endocrine System

Hormone system.

Hormones

Chemical messengers in blood.

Psychoactive Drug

Alters mood or behavior.

Substance Use Disorder

Harmful, uncontrollable drug use.

Depressants

Slow brain and body.

Tolerance

Need more for same effect.

Addiction

Compulsive use despite harm.

Withdrawal

Distress after stopping drug.

Barbiturates

Depressant, changes judgment.

Opioids

Pain relief, highly addictive.

Stimulants

Increase alertness and energy.

Hallucinogens

Distort perception.

Near-death Experience

Altered state near death.