AP Psychology Vocabulary Study Guide Key Terms & Concepts

Vocabulary flashcards covering the nervous system, neural communication, endocrine system, and psychoactive drugs based on AP Psychology Unit 1 key terms.

Nervous System

Your body's speedy communication network made of all nerve cells.

Central Nervous System (CNS)

The brain and spinal cord; the body's main decision-maker.

Peripheral Nervous System (PNS)

The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundled axons that form neural cables connecting the CNS with muscles, glands, and sense organs.

Sensory (Afferent) Neurons

Nerve cells that carry incoming information from sensory receptors to the brain/spinal cord.

Motor (Efferent) Neurons

Nerve cells that carry outgoing information from the brain/spinal cord to muscles and glands.

Interneurons

Neurons within the brain and spinal cord that communicate internally and process information.

Somatic Nervous System

The division of the PNS that controls voluntary movements of skeletal muscles.

Autonomic Nervous System (ANS)

The division of the PNS that controls involuntary actions (heartbeat, digestion).

Sympathetic Nervous System

The part of the ANS that arouses the body ("fight or flight").

Parasympathetic Nervous System

The part of the ANS that calms the body ("rest and digest").

Reflex

A simple, automatic response to a sensory stimulus (like jerking your hand off a hot stove).

Neuron

A nerve cell; the basic building block of the nervous system.

Cell Body

The part of a neuron that contains the nucleus; the cell's life-support center.

Dendrites

Branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Axon

The lengthy neuron extension that passes messages away from the cell body to other neurons/muscles.

Myelin Sheath

A fatty tissue layer insulating the axon, speeding up signal transmission.

Glial Cells (Glia)

Support cells in the nervous system that nourish, protect, and insulate neurons.

Action Potential

A brief electrical charge that travels down an axon (a neural impulse).

Threshold

The minimum level of stimulation required to trigger a neural impulse.

Refractory Period

A short resting pause after a neuron fires during which it cannot fire again.

All-or-None Response

A neuron's reaction is binary—it either fires at full strength or doesn't fire at all.

Synapse

The tiny junction/gap between the sending neuron's axon tip and the receiving neuron's dendrite.

Neurotransmitters

Chemical messengers that cross the synaptic gap to carry signals between neurons.

Reuptake

The process where sending neurons reabsorb excess neurotransmitters from the synapse.

Endorphins

Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Agonist

A molecule that mimics or increases a neurotransmitter's action.

Antagonist

A molecule that blocks or inhibits a neurotransmitter's action.

Endocrine System

The body's "slow" chemical communication system; glands that secrete hormones into the bloodstream.

Hormones

Chemical messengers produced by endocrine glands that travel through the blood to affect tissues.

Psychoactive Drug

A chemical substance that alters perceptions, moods, and consciousness.

Substance Use Disorder

Continued substance craving and use despite significant life disruption or physical risk.

Depressants

Drugs that reduce neural activity and slow down body functions (e.g., alcohol).

Tolerance

The diminishing effect of a drug over time, requiring larger doses to feel the same impact.

Addiction

Compulsive craving of drugs or behaviors despite known harmful consequences.

Withdrawal

Discomfort and distress that follow stopping the use of an addictive drug.

Barbiturates

Depressant drugs that depress CNS activity, reducing anxiety but impairing memory and judgment.

Opioids

Drugs derived from opium (or synthetic versions) that depress neural activity, temporarily lessening pain and anxiety.

Stimulants

Drugs that excite neural activity and speed up body functions (e.g., caffeine, nicotine).

Hallucinogens

Psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input.

Near-Death Experience

An altered state of consciousness reported after a close brush with death, often similar to drug-induced hallucinations.