Neurons + neurotransmitters

structure and function

Dendrite

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

soma

cell body of a neuron

axon

the extension/tail of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands and electrical signals are conducted

myelin sheath

covers the axon of some neurons and helps speed up the action potential

axon terminal

The endpoint of a neuron where neurotransmitters are stored

synapse

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

afferent neurons

send messages from the body up to the brain. APPROACH the brain.

efferent neurons

send messages from the brain to the body. EXIT the brain.

action potential

the electrical signal travelling down from the soma to the axon terminal

interneurons

connectors for other neurons

mirror neurons

Frontal lobe neurons that fire when performing certain actions or when observing another doing so. The brain's mirroring of another's action may enable imitation, language learning, and empathy.

glial cells

"housekeeping" cells that clean up after neurons. keeps the nervous system clean so the neurons can do their job.

all or none principle/firing threshold

Once a neuron reaches a firing threshold it is going to send a message. It either fires at full strength or does not fire.

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

endorphins

natural, opiate-like neurotransmitters linked to pain control and to pleasure

Epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

GABA

An inhibitory neurotransmitter in the brain that slows it down

glutamate

A major excitatory neurotransmitter; involved in memory

serotonin

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

Substance P

a neurotransmitter involved in pain perception

lock and key analogy

lock = receptor, key = neurotransmitter; Neurotransmitter must "match" receptor site.

inhibitory signals

neurotransmitters send message to calm and slow the body

excitatory signals

Neurotransmitters send messages to rev up the body

agonists

drugs that increase the action of a neurotransmitter and can block the reuptake of a neurotransmitters

antagonists

drugs that block the function of a neurotransmitter and destroy neaurotransmitters in the synapse

Reuptake

the process of neurons removing excess neurotransmitters from the synapse after they successfully delivered their message