AP Psychology Module 1.3a: Neurons, Neural Firing, and the Endocrine System

Vocabulary flashcards covering the structure and function of neurons, the process of neural firing, neurotransmitters, receptor mechanisms, and the endocrine system.

Neuron

A nerve cell that receives and sends information throughout the nervous system.

Dendrites

Neuron structures that receive messages from other neurons.

Cell body (soma)

The part of the neuron that contains the nucleus, keeps the neuron alive, and processes incoming signals.

Axon

The part of the neuron that carries the electrical impulse away from the cell body.

Myelin sheath

A fatty covering that insulates the axon and speeds up messages.

Glial cells

Cells that support, protect, and nourish neurons; some produce myelin.

Axon terminals

Structures that release neurotransmitters to communicate with other cells.

Resting potential

The neuron's charged state when it is not firing, where the inside is more negatively charged than the outside.

Threshold

The minimum stimulation needed to trigger an action potential.

Action potential

The brief electrical impulse traveling down an axon, created when positively charged ions enter the axon.

Refractory period

The brief recovery period after firing when the neuron rests and resets before it can fire another impulse.

All-or-none response

The principle that a neuron either fires a full-strength impulse or does not fire at all.

Synapse

The junction between two neurons.

Synaptic gap (cleft)

The tiny space between neurons across which neurotransmitters travel.

Neurotransmitters

Chemical messengers that cross the synaptic gap to bind to receptor sites on the receiving neuron.

Reuptake

The process by which the sending neuron reabsorbs excess neurotransmitters.

Acetylcholine (ACh)

A neurotransmitter that plays a role in muscle movement, learning, and memory.

Dopamine

A neurotransmitter that influences movement, attention, learning, and emotion.

Serotonin

A neurotransmitter that affects mood, hunger, sleep, and arousal.

Norepinephrine

A neurotransmitter that helps control alertness and arousal.

GABA

The major inhibitory neurotransmitter that slows neural activity.

Glutamate

The major excitatory neurotransmitter involved in memory; excites neurons.

Endorphins

Neurotransmitters that provide natural pain relief and pleasure.

Substance P

A neurotransmitter involved in pain perception and immune response.

Excitatory signal

A signal that increases the likelihood that a neuron will fire (acts like an accelerator).

Inhibitory signal

A signal that decreases the likelihood that a neuron will fire (acts like brakes).

Agonist

A substance that increases or mimics a neurotransmitter's action, such as morphine mimicking endorphins.

Antagonist

A substance that blocks or decreases a neurotransmitter's action, such as curare blocking acetylcholine receptors.

SSRIs

Antidepressants that partially block serotonin reuptake, allowing serotonin to remain available in the synaptic gap longer.

Endocrine system

The body's slower chemical communication system that uses glands to release hormones into the bloodstream.

Hormones

Chemical messengers that travel through the bloodstream and affect other tissues.

Pituitary gland

A gland controlled by the hypothalamus that releases hormones and directs other endocrine glands.

Hypothalamus

A brain region that connects the nervous system to the endocrine system, helps regulate the endocrine system, and controls the pituitary gland.

Adrenal glands

Endocrine glands that release hormones involved in the stress response.

Cortisol

A hormone associated with stress that helps regulate the body's response.

Epinephrine (adrenaline)

A hormone that increases heart rate, blood pressure, and available energy during danger.

Oxytocin

A hormone involved in social bonding and other bodily functions.