Biological Psychology: Neurons, Synapses, and Neurotransmitters

Biological psychology

study of the links between biological and psychological processes

Neuron

nerve cell; basic building block of the nervous system

Dendrites

extensions of a neuron that receive and integrate messages

Cell body (soma)

neuron's life-support center; contains the nucleus

Axon

extension of a neuron that passes messages through its branches

Myelin sheath

fatty tissue layer encasing axons of some neurons, enabling faster transmission

Glial cells

cells in the nervous system that support, nourish, and protect neurons; involved in learning and memory

Action potential

neural impulse; a brief electrical charge that travels down an axon

Refractory period

resting pause after a neuron fires, during which it cannot fire again until reset

Threshold

the level of stimulation required to trigger a neural impulse

All-or-none response

a neuron either fires completely or not at all

Synapse

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

Neurotransmitters

chemical messengers that cross the synaptic gap

Reuptake

neurotransmitters' reabsorption by the sending neuron

Endorphins (vocab)

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

Agonist

molecule that increases a neurotransmitter's action

Antagonist

molecule that inhibits or blocks a neurotransmitter's action

Acetylcholine ACh

Enables muscle action, learning, and memory

Dopamine

Influences movement, learning, attention, and emotion (plays an essential role in the reward system, which influences: movement, motivation, mood, reward, learning, and pleasure)

Serotonin

Affects mood, hunger, sleep, and arousal

Norepinephrine

Helps control alertness and arousal

GABA (gamma-aminobutryic acid)

A major in inhibitory neurotransmitter (calms the nervous system by reducing the excitability of neurons)

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins (table)

Neurotransmitters that influence the perception of pain or pleasure