Unit 1.3B - Neurotransmitters and Hormones

AP Psychology vocabulary from collegeboard.

Action Potential definition

A brief electrical charge that travels down the axon

All-or-Nothing Principle

A neuron either fires or it doesn’t — there’s no halfway

Depolarization

When a neuron’s charge becomes less negative, leading to firing

Refractory Period

After firing, the neuron needs time to reset before firing again

Resting Potential

The state of a neuron when it’s ready to fire but hasn’t yet

Neurotransmitters

Chemical messengers that transmit signals across the synapse

Excitatory Neurotransmitters

Encourage neurons to fire

Dopamine

An Excitatory Neurotransmitter

Involved in reward and motivation

Norepinephrine

An Excitatory Neurotransmitter

Arouses alertness and energy

Glutamate

An Excitatory Neurotransmitter

The most common excitatory neurotransmitter, linked to learning and memory

Substance P

Neurotransmitter involved in transmitting pain signals to the brain

Pain Perception

Alerts the brain to injury by transmitting pain signals

Inhibitory Neurotransmitters

Prevent neurons from firing

GABA

An Inhibitory Neurotransmitters

Calms the nervous system

Serotonin

An Inhibitory Neurotransmitters

Regulated mood and sleep

Endorphins

An Inhibitory Neurotransmitters

Natural painkillers

Multiple Sclerosis (MS)

The myelin sheath is damaged, slowing down or blocking signals

Myasthenia Gravis

An autoimmune disorder where acetylcholine receptors are attacked, leading to muscle weakness

Endocrine System

A slower communication system that uses hormones instead of neurotransmitters

Hormones

Chemical messengers that travel through the bloodstream and affect behavior and mood

Adrenaline

Increases heart rate and energy (fight-or-flight)

Oxytocin

Influences bonding and social behaviors

Leptin

Regulates hunger and fat storage

Melatonin

Regulates sleep-wake cycles

Ghrelin

Stimulates hunger