Neurons Flashcards
neuron
a nerve cell;
basic building block of nervous system
dendrites
a neuron’s busy branching extensions
the little roots that come out
they receive messages and sends impulse to cell body
axon
the stem of the neuron
sends messages and it branches to other neurons, muscle, or glands
myelin sheath
a fat tissue around the axon
enables a faster transmission speed as it hops from one neuron to the other
action potential
a neural impulse
an electrical charge that travels down an axon
Na+ goes into the cell which makes action potential negative
resting potential
positive outside(Na+) , negative inside(K)
refractory period
a period of inactivity after the neuron fired
pumps Na+ outside the neuron
threshold
the level of stimulation needed to trigger an neural impulse (action potential)
all-or-none response
a neurons reaction of firing (a full strength response) or not firing
they either fire or don’t
synapse
meeting space in between the neurons that
impulses travel down the neuron’s axon until it reaches this junction
soma
cell body of the neuron
neurotransmitters
chemical messengers that activate a hormone
influences whether or not it will generate a neural impulse
reuptake
the sending neurons reabsorb the excess neurotransmitters
Acetylcholine (ACh)
released by motor neurons
neurotransmitter plays a role in learning and memory, it is the messenger between every junction between motor neurons
when released our muscles contract, when its inhibited then we may become paralyzed (anesthesia)
Dopamine
movement, learning, attention, emotion
schizophrenia oversupply
undersupply parkinsons
Seratonin
mood, hunger, sleep, arousal
undersupply depression, given to depressed patients
Norepinephrine
alertness and arousal
can depress mood
GABA
A major inhibitory neurotransmitter
undersupply linked to seizures
Glutamate
major excitatory neurotransmitter, memory
oversupply can overstimulate the brain
can produce migraines – why people avoid msg
Endorphins
“morphine within”
this neurotransmitter is natural and links to control pain and pleasure
Agonist
binds to a receptor and simulates the same response of what it’s bind to
example: cocaine, creates oversupply of dopamine
Antagonists
binds to the receptor but inhibits it from functioning
synaptic transmission
Synaptic Transmission the process of transferring information at a synapse - see neurotransmitter.
terminal buttons
small knobs at the end of the axon that secrete chemicals called neurotransmitters
motor neuron
impulses from brain or spinal cord to a muscle or gland
sensory neuron
Neurons that carry incoming info from the sensory receptors to the CNS
impulses to brain and spinal cord
