AP Psych Unit 2 Quiz

Dendrite

Receives messages from other neurons.

Axon

Carries electrical impulses away from the cell body.

Myelin Sheath

Fatty layer around axons; speeds up neural impulses.

Node of Ranvier

Gaps in the myelin sheath; helps action potentials jump faster (saltatory conduction).

Nucleus

Control center of the neuron; contains DNA.

Afferent Neurons (Sensory)

Carry messages from body to brain (e.g., touching a hot stove → signal goes to brain).

Efferent Neurons (Motor)

Carry messages from brain to body (e.g., brain sends signal to move hand away from stove).

Synaptic Gap/Cleft

Tiny space between neurons where neurotransmitters are released.

Agonist

Chemical/drug that mimics neurotransmitters and increases their effect (e.g., nicotine mimics acetylcholine).

Electric Potential

If it increases, likelihood of a neuron firing goes up.

Action Potential

Electrical impulse that travels down the axon (all-or-none response).

Dopamine

Movement, learning, reward, addiction (too much = schizophrenia, too little = Parkinson’s).

Serotonin

Mood, sleep, appetite (low levels = depression).

GABA (Gamma-Aminobutyric Acid)

Inhibitory; calms the nervous system (linked to anxiety if low).

Glutamate

Excitatory; involved in learning & memory (too much = migraines/seizures).

Acetylcholine (ACh)

Muscle action, learning, memory (blocked in Alzheimer’s disease).

Motor Neurons at Relaxed State

Not firing, but ready to send action potential if threshold is met.

Corpus Callosum

Connects the two brain hemispheres; allows communication between left/right sides.

Multiple Sclerosis (MS)

Autoimmune disorder where the myelin sheath is damaged → slower neural transmission, muscle weakness, vision problems.