(4) nervous system [main/basic] Flashcards
functional basic unit of the nervous system
neurons
parts of the neuron structure
dendrites cell body nucleus axon myelin sheath + schwann cell + nodes of ranvier axon terminal
what do neurons make
neurotransmitters
(def) neurotransmitter
chemical messenger
what travels in the neuron
action potential
(def) action potential
electrical signal
4 nervous system tissues
neurons
nerve
ganglia
neuroglia
(def) neuroglia
neural glue
helper cell
(func) neuroglia
support & protect the neurons
maintain homeostasis in the fluid surrounding the neurons
gray matter
non-myelinated matter
beginnings and ends of neurons
edges of the brain
white matter
myelinated matter
axons of neurons
connects gray matter to each other
resting potential
neuron at rest - not firing/no signal transmission
stimulus
causes a change in ion charge across the neuron membrane
action potential
minimum threshold of charge across the membrane reached - all or nothing firing
refractory period
period of time before the membrane returns to resting potential
5 neurotransmitters
epinephrine dopamine endorphins serotonin acetylcholine
2 types of neurotransmitter mimics
agonists (excitatory)
antagonists (inhibitory)
agonists (excitatory)
stimulants
increase neurotransmitter effects
ex. nicotine, caffeine, cocaine, amphetamines
antagonists (inhibitory)
depressants
slow neurotransmitter effects
ex. botox, alcohol, heroin, oxycodone