Module 2 HW Questions Flashcards
What type of membrane channel will an excitatory neurotransmitter open to initiate depolarization in a resting neuron?
ligand gated
What type of channels open once a neuron reaches threshold?
voltage gated
Which phase of an action potential reaches +30mV?
peak
Which phase of an action potential are voltage gated sodium channels closed and voltage gated potassium channels open?
repolarization
Which phase of an action potential are voltage gated potassium channels closed and voltage gated sodium channels open?
depolarization
Which phase of neuron action potential does the membrane become more negative than resting membrane potential?
hyperpolarization
What process depolarizes and then repolarizes each section of an axon as it travels down the axon?
propagation of an action potential
What type of conduction of an action potential only depolarizes the nodes of ranvier?
saltatory conduction
Which refractory phase can a neuron respond to additional signals if the signals are stronger than normal?
relative refractory
What type of membrane potential makes the membranes less negative inside, but it does not reach threshold?
subthreshold potentials (EPSP)
Which type of potential moves the neurons membrane away from zero?
local hyperpolarization (IPSP)
What is a decrease in membrane potential as it moves from the postsynaptic synapse toward the soma?
decremental conduction
The cytoplasm of a neuron at rest is _______ in potassium and _________ in sodium ions?
high, low
A neuron’s cell membrane has more _____ leaky channels than _______ leaky cells
K+, Na+
The charges across a neuron’s cell membrane at rest are ____________ on the outside and ____________ on the inside
positive, negative
What is the resting membrane potential of a neuron?
-70mV
When is neuron’s cell membrane considered polarized?
at rest
How do intracellular AAs affect resting membrane potential of a cell membrane?
bind with K+
What extracellular condition reduces potassium efflux making the inside of a neuron more positive?
hyperkalemia
Low extracellular concentration of this ion is harder for a neuron to generate an AP
potassium
Which ion must enter a neuron to move it from resting membrane potential to an AP?
sodium
Vesicular protein that calcium binds to
synaptotagmin
What is syntaxin?
a tSNARE
G-protein subunit with GTP attached:
alpha
SNAP25 is a….
tSNARE
geometric protein that reformed vesicles
clathrin
What is synaptobrevin?
a vSNARE
Arrange the events of a synapse in the correct order beginning with the action potential arriving at the axon terminal
1) AP arrives at terminal
2) voltage gated calcium channels open
3) calcium influx into the presynaptic terminal
4) vesicles merge with presynaptic membrane
5) NT released
6) NT bind with receptors on postsynaptic membrane
7) ligand gated ionotropic sodium receptors open
8) sodium influx into the postsynaptic neuron
9) postsynaptic membrane depolarizes
10) NT is removed from the synapse ending its effect
What is the correct order of vesicular exocytosis?
1) vesicle docks at active zone on presynaptic membrane
2) vSNAREs and tSNAREs intertwine
3) vesicle fuses with presynaptic membrane
4) vesicle releases NT
The amount and frequency of calcium influx is directly _______________ to the amount and frequency of NT released
proportional
Which type of CNS synapse secretes neurotransmitters?
chemical
Which synaptic structure contains reuptake pumps to transport neurotransmitters back into the neuron?
presynaptic membrane
Where on the presynaptic membrane do vesicles dock and release neurotransmitters?
active zone
What type of synapse has one axon synapsing with several other neurons?
divergent
What type of synapse has several neurons synapsing with the same single neuron?
convergent
Which direction do signals typically move at a synapse?
from presynaptic neuron to postsynaptic neuron
What type of receptor responds rapidly when stimulated by a neurotransmitter?
ligand gated ionotropic
What type of receptor loops in and out of the membrane seven times and is linked to a G protein?
metabotropic
Which type of ionotropic ligand gated channels allow sodium and potassium to flow through?
cation
Which type of NT opens ligand gated anion channels?
inhibitory
What is the minimum voltage required to open voltage gated calcium in the axon terminal membrane?
4mV
Why does rapid firing of nerve signals increase the postsynaptic response?
more NT released
Which type of summation involves more than one neuron sending signals to the same neuron simultaneously?
spatial
How does temporal summation stimulate a receiving neuron?
repetitive signals sent by one neuron
What does calcium initially bind with when it enters a resting axon terminal?
calmodulin
What type of neurotransmitter receptor functions to activate DNA transcription?
GPCR
Why do the dendrites and soma of a CNS postsynaptic neuron require repetitive signals from a presynaptic neuron for it to generate an AP?
they have few if any voltage gated ionotropic channels
Which type of postsynaptic potential moves the membrane closer to threshold?
EPSP
How do IPSPs affect the postsynaptic membrane?
causes hyper-polarization
