neuron-->substance-p

BAKAAAAA

Neurons

Nerve cells; the basic building blocks of the nervous system.

Cell body (soma)

The neuron’s life-support center that processes information.

Dendrites

Branchlike fibers that receive messages from sensory receptors or other neurons and conduct impulses toward the cell body.

Axon hillock

Region where the neuron integrates signals and may trigger an action potential.

Axon

Long fiber that transmits electrical impulses away from the cell body.

Myelin sheath

Fatty tissue that insulates axons and speeds neural impulses.

Nodes of Ranvier

Gaps in the myelin sheath that help speed up signal transmission.

Terminal buttons

Small structures at axon ends that release neurotransmitters.

Glial cells

Support, nourish, and protect neurons; play a role in learning and memory.

Resting potential

The neuron’s stable, negative charge when not firing.

Threshold

The level of stimulation required to trigger a neural impulse.

Action potential (nerve impulse)

A brief electrical charge that travels down the axon.

All-or-none response

A neuron fires completely or not at all.

Refractory period

A brief resting phase after a neuron fires when it cannot fire again.

Synapse

The gap between neurons where neurotransmitters are released.

Reuptake

The reabsorption of neurotransmitters by the sending neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

Acetylcholine (ACh)

Enables muscle action, learning, and memory.

Dopamine

Influences movement, learning, attention, and emotion.

Serotonin

Affects mood, hunger, sleep, and arousal.

Norepinephrine

Helps control alertness and arousal.

GABA

Major inhibitory neurotransmitter, calming neural activity.

Glutamate

Major excitatory neurotransmitter, involved in memory.

Endorphins

Natural opiates that reduce pain and boost pleasure.

Substance P

Neurotransmitter involved in pain perception.