Unit 3: Biological Bases of Behavior Flashcards
neuron
a nerve cell that is the basic building block of the nervous system
cell body/soma
the part of the neuron that contains the nucleus, the cell’s life-support center
dendrites
bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body
axon
attached to the soma, the neuron extension that passes messages through its messages
terminal branches
located at the end of the soma, these hold synaptic vessels that store neurotransmitters
myelin sheath
the fatty tissue layer segmentally encasing the axons of some neurons; increases transmission speed and provides insulation, and play a role in motor skills
gilal cells
cells that support, nourish, and protect neurons; they play a role in learning, thinking, and memory
action potential
an electrical signal that neurons communicate through, based on movement of ions between the outside and inside of the cell
threshold
the level of stimulation required to trigger a neural impulse
refractory period
a resting pause the neuron must take in between communications, until the axon returns to its resting state
all-or-none response
more stimulation does NOT produce a more intense neural response: instead, the neuron’s reaction is all-or-none, meaning they fire or they don’t
synapse
the junction between the axon and tip of the sending neuron and the dendrite or cell body of the receiving neuron; the tiny gap is called the synaptic gap or synaptic cleft
acetylcholine (ACh)
enables muscle action, learning, and memory
What happens with ACh in Alzhemiers’ disease?
ACh-producing neurons deteriorate
dopamine
the neurotransmitter that influences movement, learning, attention, and emotion
What does an oversupply/undersupply of dopamine lead to?
an oversupply of dopamine is linked to schizophrenia; an undersupply of dopamine is linked to tremors and decreased mobility in Parkinson’s disease
serotonin
the neurotransmitter that affects mood, hunger, sleep, and arousal
What does an undersupply of serotonin lead to?
an undersupply of serotonin is linked to depression; some drugs that raise serotonin levels are used to treat depression
norepinephrine
the neurotransmitter that helps control alertness and arousal; an undersupply of norepinephrine is linked to a depressed mood
GABA (gamma-aminobutyric acid)
a major inhibitory neurotransmitter
glutamate
a major memor and excitatory neurotransmitter
What does an undersupply of GABA lead to?
an undersupply of GABA is linked to seizures, tremors, and insomnia
What does an oversupply of glutamate lead to?
an oversupply of glutamate leads to overstimulation of the brain, producing migranes or seizures (which is why some people avoid MSG, monosodium gluamate, in their food)
endorphins
neurotransmitters that influence the perception of pain or pleasure
reuptake
a neurotransmitter’s reabsorption by the sending neuron
agonist
a drug that excites neuron firing by increasing a neurotransmitter’s action
antagonist
a drug that inhibits or blocks neuron firing, and can also work by blocking reputake