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WorksheetsNeurophysiology
Total questions: 66
Worksheet time: 41mins
What is the resting membrane potential?
The potential energy generated by separated charge
The ability of neurons to rapidly change their membrane potential
The charge difference across the plasma membrane
The state of a neuron when it is not transmitting a signal
What makes neurons different from most other cells in terms of membrane potential?
Neurons have a resting membrane potential
Neurons can rapidly change their resting membrane potential
Neurons do not have a membrane potential
Neurons have a constant membrane potential
What is voltage a measure of?
The speed of signal transmission in neurons
The potential energy generated by separated charge
The amount of neurotransmitters released
The resistance across the plasma membrane
How is voltage measured?
In amperes (A)
In ohms (Ω)
In volts (V) or millivolts (mV)
In watts (W)
What is another term for potential difference?
Resting potential
Action potential
Membrane potential
Voltage
What results in a higher voltage across the plasma membrane?
Lower charge difference between points
Greater charge difference between points
Constant charge difference between points
No charge difference between points
What is the average resting membrane potential of neurons?
-70 mV
+40 mV
0 mV
-90 mV
What does it mean when a resting membrane is described as polarized?
It has a positive charge inside the cell.
It has a negative charge inside the cell.
It has no charge difference across the membrane.
It has equal charges inside and outside the cell.
What is the range of the resting membrane potential in neurons?
-10 to -30 mV
-20 to -50 mV
-40 to -90 mV
-60 to -100 mV
What is the primary reason for the generation of resting membrane potential?
Differences in ionic composition
Differences in temperature
Differences in cell size
Differences in pH levels
Which ion has a higher concentration in the extracellular fluid (ECF) compared to the intracellular fluid (ICF)?
Na+
K+
Ca2+
Cl-
How much more permeable is the plasma membrane to K+ compared to Na+?
10 times
15 times
25 times
30 times
What is the role of the sodium-potassium pump (Na+/K+ ATPase) in maintaining resting membrane potential?
It maintains concentration gradients for Na+ and K+
It generates ATP for the cell
It transports glucose into the cell
It synthesizes proteins
How many Na+ ions are pumped out of the cell by the sodium-potassium pump for every 2 K+ ions pumped back in?
1
2
3
4
What causes changes in membrane potential?
Changes in the concentration of ions across the membrane
Changes in the temperature of the cell
Changes in the size of the cell
Changes in the shape of the cell
What are the two types of signals produced by changes in membrane potential?
Electrical signals and chemical signals
Action potentials and graded potentials
Mechanical signals and thermal signals
Sensory signals and motor signals
Membrane potential changes when:
Membrane permeability to ions changes
The cell undergoes mitosis
The cell is exposed to light
The cell is in a hypertonic solution
What is the principal way neurons send signals?
Through chemical reactions
Through action potentials
Through muscle contractions
Through blood flow
Where do action potentials occur?
On the membranes of muscle cells and axons of neurons
In the bloodstream
In the digestive system
On the surface of the skin
What is the approximate change in voltage during an action potential?
50 mV
75 mV
100 mV
150 mV
Do action potentials decay over distance?
Yes, they decay rapidly
Yes, they decay slowly
No, they do not decay over distance
They decay only in muscle cells
What is another term for action potentials in neurons?
Muscle impulse
Nerve impulse
Blood impulse
Chemical impulse
Which of the following is NOT a phase of an action potential?
Depolarization
Repolarization
Hyperpolarization
Hypopolarization
During which phase of an action potential does the membrane potential become more positive?
Depolarization
Repolarization
Hyperpolarization
Resting potential
What occurs during the repolarization phase of an action potential?
Sodium ions enter the cell
Potassium ions leave the cell
Calcium ions enter the cell
Chloride ions leave the cell
Which phase of an action potential is characterized by the membrane potential becoming more negative than the resting potential?
Depolarization
Repolarization
Hyperpolarization
Threshold potential
What does repolarization reset in a cell?
A) Ionic conditions
B) Electrical conditions
C) Both ionic and electrical conditions
D) Neither ionic nor electrical conditions
What restores ionic conditions after repolarization?
A) Na+/K+ pumps
B) Ca2+ channels
C) Cl- channels
D) H+ pumps
What initiates an action potential?
A) A neurotransmitter
B) A decrease in temperature
C) A change in pH
D) A decrease in voltage
What happens when the voltage changes at least +15mV?
A) The action potential stops
B) The threshold is reached
C) The cell becomes hyperpolarized
D) The cell becomes depolarized
What type of channels open when the threshold is reached?
A) Voltage gated K+ channels
B) Voltage gated Na+ channels
C) Ligand gated Cl- channels
D) Ligand gated Ca2+ channels
What does it mean when action potentials are described as "all or none"?
A) They occur only if the threshold is reached
B) They occur only if the voltage change is subthreshold
C) They occur only if the cell is hyperpolarized
D) They occur only if the cell is depolarized
What occurs while an action potential is in progress?
Refractory period
Resting potential
Hyperpolarization
Synaptic transmission
What is the time from opening to closing of Na⁺ channels called?
Relative refractory period
Absolute refractory period
Resting period
Depolarization period
During which period are Na⁺ channels closed and K⁺ channels still open?
Absolute refractory period
Resting period
Relative refractory period
Depolarization period
Which of the following is true about the relative refractory period?
Na⁺ channels are open
K⁺ channels are closed
Na⁺ channels are closed and K⁺ channels are still open
Both Na⁺ and K⁺ channels are closed
What is the conduction velocity of continuous conduction in an axon?
2 meters/sec
10 meters/sec
50 meters/sec
100 meters/sec
What is the conduction velocity of saltatory conduction in an axon?
2 meters/sec
10 meters/sec
50 meters/sec
100 meters/sec
Which factor does NOT affect the conduction velocity of an action potential (AP)?
Degree of myelination
Diameter of the axon
Length of the axon
Type of conduction (continuous or saltatory)
Which type of conduction is faster?
Continuous conduction
Saltatory conduction
Both are equally fast
Neither, they are both slow
What is the main topic of the A&P Flix video?
Neurotransmitter release
Propagation of an Action Potential
Synaptic transmission
Muscle contraction
In which part of the axon does an action potential propagate in a continuous fashion?
Myelinated axons
Dendrites
Unmyelinated axons
Synaptic cleft
What is the initial segment where an action potential is generated called?
Synaptic terminal
Axon hillock
Dendritic spine
Node of Ranvier
What are graded potentials?
Long-lasting, widespread changes in membrane potential
Short-lived, localized changes in membrane potential
Short-lived, widespread changes in membrane potential
Long-lasting, localized changes in membrane potential
What triggers graded potentials?
A stimulus that closes gated ion channels
A stimulus that opens gated ion channels
A stimulus that opens voltage-gated channels
A stimulus that closes voltage-gated channels
How are graded potentials named?
According to their duration and intensity
According to their location and function
According to their amplitude and frequency
According to their speed and direction
What is a graded potential that moves the voltage closer to the threshold called?
Hyperpolarizing GP
Depolarizing GP
Repolarizing GP
Stabilizing GP
What is a graded potential that moves the voltage farther from the threshold called?
Hyperpolarizing GP
Depolarizing GP
Repolarizing GP
Stabilizing GP
What can a larger stimulus that depolarizes above the threshold trigger in a postsynaptic neuron?
Hyperpolarization
Action potential
Resting potential
Inhibition
What are the two types of postsynaptic potentials?
Excitatory and Inhibitory
Positive and Negative
Active and Passive
Strong and Weak
What does EPSP stand for?
Excitatory presynaptic potentials
Excitatory postsynaptic potentials
Inhibitory presynaptic potentials
Inhibitory postsynaptic potentials
What does IPSP stand for?
Inhibitory presynaptic potentials
Inhibitory postsynaptic potentials
Excitatory presynaptic potentials
Excitatory postsynaptic potentials
What is the nature of a single postsynaptic potential?
Always suprathreshold
Always subthreshold
Sometimes suprathreshold
Sometimes subthreshold
In how many ways can summation occur?
1
2
3
4
What is temporal summation?
One or more presynaptic neurons transmit impulses in rapid-fire order
One or more postsynaptic neurons transmit impulses in rapid-fire order
One presynaptic neuron transmits impulses slowly
Multiple presynaptic neurons transmit impulses slowly
Which of the following is involved in maintaining the resting membrane potential of neurons?
Na+/K+ ATPase pump moves 3Na+ in for every 2K+ out
Na+/K+ ATPase pump moves 3K+ in for every 2Na+ out
Na+/K+ ATPase pump moves 3Na+ out for every 2K+ in
Na+/K+ ATPase pump moves 3K+ out for every 2Na+ in
What is the role of the sodium-potassium pump in maintaining the resting membrane potential of a neuron?
It pumps sodium ions out and potassium ions into the neuron, against their concentration gradients.
It allows sodium and potassium ions to flow down their concentration gradients.
It equalizes the concentrations of sodium and potassium ions inside and outside the neuron.
It generates action potentials by rapidly changing the permeability of the membrane to sodium and potassium.
.
Relative to extracellular fluid, the interior of a neuron has a negative charge because _________
potassium is actively pumped into the cell
sodium is actively pumped into the cell
potassium diffuses out of the cell
chloride ions are actively pumped into the cell
.
Relative to extracellular fluid, the interior of a neuron has a negative charge because _________
potassium is actively pumped into the cell
sodium is actively pumped into the cell
potassium diffuses out of the cell
chloride ions are actively pumped into the cell
Match the following
Depolarization
cell is getting more +, Na+ in
Repolarization
cell is getting more -, K+ out
Hyperpolarization
cell gets more -, K+ channels close slow
Threshold potential
-55 mV
Resting potential
-70 mV
At the peak of the action potential, the membrane potential is:
exactly at the Na+ equilibrium potential (VNa)
close to but more positive than the Na+ equilibrium potential (VNa)
close to but less positive than the Na+ equilibrium potential (VNa)
exactly at 0 mV
the same as the resting membrane potential (Vrest)
Match the following
Depolarization
cell is getting more +, Na+ in
Repolarization
cell is getting more -, K+ out
Hyperpolarization
cell gets more -, K+ channels close slow
Threshold potential
-55 mV
Resting potential
-70 mV
Which ion is pumped into the axon of a neuron to help maintain the resting potential?
calcium
hydrogen
potassium
sodium
