Myers AP Psych Unit 3 - Module 9

Based on the Myers Psychology for the AP Course textbook's Module 9.

Biological psychology

Study of the links between biological (genetic, neural, hormonal) and psychological processes.

Neuron

Basic nerve cell that transmits information.

Dendrites

Branching extensions of a neuron that receive messages.

Cell body (soma)

Neuron’s life center; processes incoming information.

Axon

Long fiber that passes messages away to other neurons, muscles, or glands.

Myelin sheath

Fatty layer that insulates the axon and speeds up neural impulses; deterioration leads to multiple sclerosis.

Terminal branches

Ending of an axon that forms junctions with other cells and releases neurotransmitters.

Glial cells

Support, nourish, and protect neurons; play roles in learning and thinking.

Resting potential

Neuron’s stable, negative charge when inactive.

Depolarization

Positive ions enter the neuron, triggering the action potential.

Repolarization

Neuron resets after firing; returns to negative inside.

Refractory period

Time after firing during which neuron cannot fire again.

Threshold

Minimum level of stimulation required to trigger an impulse.

All-or-none response

Neuron either fires completely or doesn’t fire at all.

Synapse

Site of communication between neurons (synaptic gap).

Neurotransmitters

Chemical messengers that cross the synaptic gap between neurons.

Reuptake

Process by which neurotransmitters are reabsorbed by the sending neuron.

Agonist

Molecule that mimics a neurotransmitter, increasing its effect.

Antagonist

Molecule that blocks a neurotransmitter’s action.

Acetylcholine (ACh)

Enables muscle movement, learning, and memory; undersupply linked to Alzheimer’s.

Dopamine

Influences movement, learning, attention, emotion; excess = schizophrenia, undersupply = Parkinson’s.

Serotonin

Affects mood, hunger, sleep, arousal; undersupply = depression.

Norepinephrine

Controls alertness and arousal; undersupply = depressed mood.

GABA

Major inhibitory neurotransmitter; undersupply = seizures, tremors, insomnia.

Glutamate

Major excitatory neurotransmitter; oversupply = migraines or seizures.

Endorphins

Natural opiates for pain control and pleasure; opiate drugs mimic them.