Psych - Chapter 3 (Neurons & Communication)

Action potential

Electrical impulse that travels down an axon to send a message

All-or-None principle

A neuron either fires completely or does not fire at all

Axon

The long part of a neuron that sends messages away from the cell body.

Dendrite

Branch-like parts of a neuron that receive messages from other neurons.

Glial Cell

Support cells that protect, nourish, and help neurons communicate.

Membrane potential

Difference in electrical charge inside and outside a neuron.M

Myelin sheath

Fatty covering around axons that speeds up nerve signals.

Neuron

A nerve cell that receives, processes, and sends information.

Nodes of Ranvier

Gaps in the myelin sheath that help signals travel faster.

Neuroplasticity

The brain’s ability to change, adapt, and form new connections.

Resting potential

The neuron’s ready state before it sends a signal

Semipermeable membrane

A cell membrane that lets some substances pass through but blocks others.

Soma

The cell body of a neuron.

Synaptic cleft

Tiny gap between neurons where communication occurs.

Synaptic vesicle

Small sacs that store neurotransmitters.

Terminal button

End of an axon that releases neurotransmitters.

Threshold of excitation

The minimum level needed for a neuron to fire.

Agonist

A drug that boosts or copies a neurotransmitters’ effect.

Antagonist

A drug that blocks a neurotransmitter’s effect.

Neurotransmitter

Chemical messenger that neurons use to communicate.

Receptor

The spot where neurotransmitter attach.

Reuptake

When neurotransmitters are reabsorbed into the sending neuron.S