AP Psychology module 9 vocab

Neurons

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

Cell body

The part of the neuron that contains the nucleus, the cells control center.

Dendrites

The neuron’s branching extensions that receive and integrate messages, conducting impulses toward the cell body.

Axons

Neuron extensions that pass messages through its branches to other neurons or to muscles or glands.

Myelin sheath

A fatty tissue layer that segmentally encases the axons of some neurons, enabling greater transmission speed of neural impulses between nodes.

Glial cells

Cells in the nervous system that support and protect neurons. They also play a role in learning, thinking, and memory.

Action potential

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

Threshold

The level of stimulation required to trigger a neural impulse.

Refractory period

A brief resting pause that occurs after a neuron has fired, subsequent action potentials cannot occur until the axon returns to resting state.

All-or-none response

Refers to a neuron’s reaction of either firing with a full-strength response or not firing.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, influencing whether that neuron will generate a neural impulse.

Re-uptake

A neurotransmitter’s reabsorption by the sending neuron.

Endorphins

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

Agonist

Molecules that increase a neurotransmitter’s action.

Antagonists

Molecules that decrease a neurotransmitter’s action.