Anatomy semester 2 quiz 2 Flashcards
where exactly do neurons communicate with one another (or with other cells)?
synapse
presynaptic neuron
sender
neuron conducting impulse
postsynaptic neuron
reciever
neuron recieving input
synaptic transmission
process by which the impulse in the presynaptic neuron signals to postsynaptic neuron
Process of synaptic transmission number 1
impulse conducting axon —-> synapse
Process of synaptic transmission number 2
synaptic knobs on axons release neurotransmitters
process of synaptic transmission number 3
neurotransmitters released when impulse reaches end of axon, neurotransmitter diffuse across synaptic cleft
process of synaptic transmission number 4
neurotransmitters reach postsynaptic neuron
-exciatory or inhibitory
Neurotransmitter
chemical messenger
depolarized
state at which the resting potential is reversed as sodium ions rush into the neuron
Polarized
electrical condition of the plasma membrance of a resting neuron
sodium cations
at rest, this ion is at greater concentration outside of the cell than inside
NMJ
when a synapse exists betweena neuron and a muscle cell
resting potential
the condition in which there are fewer positive ions on the inside of the neuron’s plasma membrance than there are on its outer face
irritability
the ability to respond to a stimulus and convert it to a nerve impulse
potassium cations
at rest, the major positive ions inside the cell are this ion
an action potential is commonly reffered to as a
nerve impulse
myelin
speeds up the transmission of a nerve impulse
saltatory conduction
the transmission of nerve impulses in myelinated axons leaps from node along the fiber
resting potential
the plasma membrane is inactive. THe condition in which there are fewer positive ions on the inside of the neurons plasma membrance than there are on its outer face
action potential
a nerve impulse.
depolarization
when the potassium ions begin to move outside to restore the resting membrane potential
repolarization
when the potassium ions begin to move outside to restore the resting membrane potential
all or nothing law
if a nerve fiber carries any impulse, it will carry a full strength impulse
conductivity
the ability to transmit the impulse to other neurons, muscles, or glands
sodium potassium pump
found in out cell membranes, pumps sodium out of the cell and potassium into the cell, powered by ATP
Refractory period
period of the neuron during which it cannot respond to a second stimulus
synapse
space between the neurons
a depolarization event conducted along the membrane of a muscle cell or nerve fiber
action potential
a rapid sequence of changes in the voltage across a membrance
action potential
sequence of events for a nerve impulse step 1
nerve cell membrane maintains resting potential by diffusion of Na+ and K+ down their concentration gradients as the cell pumps them up the gradients
sequence of events for a nerve impulse step 2
neurons recieve stimulation,k causing local potentials, which may sum to reach threshold
sequence of events for anerve impulse step 3
sodium channels in the trigger zone of the axon open
sequence of events for a nerve impulse step 4
sodium ions diffuse inward, depolarizing the membrane
sequence of events for a nerve impulse step 5
potassium channels in the membrane open
sequence of events for a nerve impulse step 6
potassium ions diffuse outward, repolarizing the membrane
sequence of events for a nerve impulse step 7
the resulting action potential causes an electric current that stimulates adjacent portions of the membrane
sequence of events for a nerve impulse step 8
action potentials occur sequentially along the length of the axon
neurons resting potential
neurons hold a negative change -70mv
a neuron remains at resting potential when there is not enough of a ______ present
stimulus
when a neuron is at resting potential it holds a slightly ________ charge
negative
neurotransmitter stimulate the gated _____ channels to open in the trigger zone of the axon
sodium
The neuron experiences depolarizatin when ______ cations move inside
sodium
Immediately after depolarization, ______ channels open
potassium
depolarization means the neuron becomes ______ negatively charged.
less
Repolarization means the neuron becomes ____ negatively charged
more
the rapid depolarization and repolarization of a region causes an _____ current, which stimulates th enext region
electric
