Module 9

biological psychology

the scientific study of how biological processes affect psychological processes

neurons

the building blocks of the central nervous system that are responsible for

• receiving information from other neurons

• carrying information down the body’s length

• passing information to the next neuron in line

dendrites

tree-like extensions at the beginning of the neuron

• receive information from a neighboring neuron and start an impulse toward the cell body

axon

longest part of a neuron

• passes messages away from the cell body to the next neuron

soma

the cell body of the neuron

• contains the cell nucleus to keep the cell healthy and functioning

myelin sheath

protects axon

• speeds up transmission of information

axon terminals

contain neurotransmitters

• sends message to next neuron

action potential

positively charged sodium/potassium ions flood through the cell membrane which causes the neuron to fire impulses (electrical charge that flows down the axon)

refractory period

neuron pumps positively charged sodium/potassium ions back outside

resting potential

positively charged ions are inside, negatively charged ions are outside

threshold

the level of stimulation in order to trigger an impulse

all or none principle

states that a neuron always fires with the same intensity

• neuron will either transmit an impulse completely or not at all

inhibitory vs excitatory effect

inhibitory effect makes action potential less likely

excitatory effect makes action potential more likely

synapse

 tiny fluid filled gap between neurons

neurotransmitters

travel across the synapse and latch onto receptor sites on the dendrite of the next neuron (can only attach to receptor sites that fit their shape)

reuptake

when the sending neuron reabsorbs excess neurotransmitters

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

a major inhibitory neurotransmitter

Glutamate

a major excitatory neurotransmitter, involved in memory

agonist

boosts the effects of a neurotransmitter

antagonist

blocks the effects of a neurotransmitter