Unit 2 - Terminology Flashcards
neuron
nerve cell
basic building block of nervous system
dendrites
bushy, branching extensions on a neuron
receive and integrate messages by conducting impulses toward the cell body
cell body
part of neuron that contains the nucleus
axon
part of neuron that passes impulses from the cell body to other neurons, muscles, or glands
myelin sheath
covers axon of some neurons
enables much faster transmission speed as impulses hop from one node to the next
neural impulse
action potential
electrical signal that travels down the axon of a neuron
terminal branches of axon
form junctions with other cells to send out impulses from neuron
glial cells/glia
cells in nervous system that support, nourish, and protect neurons
assist in learning, thinking, memory
action potential
neural impulse
brief electrical charge that travels down the axon
threshold
level of stimulation necessary to trigger a neural impulse
refractory period
brief resting pause that occurs after a neuron has fired
all-or-none response
neuron either fires a full strength impulse or fires nothing at all
synapse
junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
synaptic cleft
tiny gap at the synapse
neurotransmitters
cross the synaptic clefts between neurons
when released by sending neuron, they bind to receptor sites on the receiving neuron
influences whether or not a neuron will generate a neural impulse
reuptake
when extra neurotransmitters get reabsorbed by the sending neuron
types of neurotransmitters (7)
acetylcholine (ACh), dopamine, serotonin, norepinephrine, GABA, glutamate, endorphins
acetylcholine (ACh)
enables muscle action, learning, memory
malfunction: undersupply —> Alzheimer’s disease
dopamine
influences movement, learning, attention, emotion
malfunction: oversupply —> schizophrenia; undersupply —> tremors/decreased mobility in Parkinson’s
serotonin
affects mood, hunger, sleep, arousal
malfunction: undersupply —> depression
norepinephrine
helps control alertness and arousal
malfunction: undersupply —> depressed mood
GABA (gamma-aminobutyric acid)
inhibitory neurotransmitter
malfunction: undersupply —> seizures, tremors, insomnia
glutamate
excitatory neurotransmitter, memory
malfunction: oversupply —> migraines/seizures
endorphins
influence perception of pain and pleasure
malfunction: oversupply from opiates —> suppression of natural endorphin supply
agonist
molecule that increases action of a neurotransmitter
antagonists
inhibits the action of a neurotransmitter
central nervous system (CNS)
brain and spinal cord
peripheral nervous system (PNS)
sensory and motor neurons that connect the CNS to the rest of the body
contains somatic and autonomic nervous systems
types of neurons (3)
sensory, motor, inter-neurons
sensory neurons
carry messages from body tissues and sensory receptors inward (afferent)
motor neurons
carry instructions for muscles and glands out from CNS (efferent)
inter-neurons
within brain and spinal cord
process info between sensory and motor neurons