284553
Which of the following statements characterizes the depolarization state of neuron ?
1 \(\mathrm{Na}^{+}\)gets inside through ion channels
2 \(\mathrm{Na}^{+}\)gets outside through channels
3 \(\mathrm{K}^{+}\)channels remain open
4 All of the above
Explanation:
A During the depolarization of neuron, sodium ion \(\left(\mathrm{Na}^{+}\right)\)gets inside through ion channels. In the resting state of a neuron, the inside of the cell is negative relative to the outside. This is because there are more negatively charged ions (such as chloride ions) inside the cell than outside of the cell. When a neuron is depolarized, the inside of the cell becomes less negative than outside. This because sodium ions \(\left(\mathrm{Na}^{+}\right)\)move into the cell through voltage- gated sodium channels.
UP CPMT-2012
Neural Control and Coordination
284554
During the propagation of a nerve impute, the action potential results from the movement of
1 \(\mathrm{K}^{+}\)ions from extracellular fluid to intracellular fluid
2 \(\mathrm{Na}^{+}\)ions from intracellular fluid extracellular fluid
3 \(\mathrm{K}^{+}\)ions from intracellular fluid to extracellular fluid
4 \(\mathrm{Na}^{+}\)ions from extracellular fluid to intracellular fluid
Explanation:
D During the propagation of a nerve impulse, the action potential results from the movement of sodium ions \(\left(\mathrm{Na}^{+}\right)\)from the extracellular fluid to the intracellular fluid. This influx of sodium ions causes the membrane potential to depolarize, or become more positive. Once the membrane potential reaches a threshold-level, voltage-gated sodium channel open and allow even more sodium ions to enter the cell. This rapid influx of sodium ions creates an action potential, which is a wave of depolarization that travels down the axon of the neuron.
BHU PMT (Screening)-2010
Neural Control and Coordination
284555
An investigator places an isolated neuron in a calcium-free medium, gives the neuron a suprathreshold stimulus and then performs an assay to test whether neurotransmitter is released into the medium. Which of the following outcomes would you predict?
1 No neurotransmitter is detected since influx of calcium into the synaptic knob is required for neurotransmitter release
2 No neurotransmitter is detected since influx of calcium is required in order for the neuron to conduct an action potential
3 Neurotransmitter is detected since calcium is not required for action potential conduction and the initial stimulus was suprathreshold
4 We cannot predict the outcome without knowing whether the neuron was myelinated
Explanation:
A In this given reason, no neurotransmitter is detected since the influx of calcium in to the synaptic knob is required for neurotransmitter release. \(\mathrm{Ca}^{2+}\) triggers synaptic vesicle exocytosis, thereby releasing the neurotransmitters contained in the vesicles and initiating synaptic transmission.
J and K CET-2012
Neural Control and Coordination
284556
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge?
1 First negative, then positive and again back to negative
2 First positive, then negative and continue to be negative
3 First negative, then positive and continue to be positive
4 First positive, then negative and again back to positive
Explanation:
A Before the generation of an action potential, the neuron is in resting state that is \(-70 \mathrm{mV}\), inside the cell. During action potential as transmission of nerve impulse the membrane potential inside the neuron rises up to \(30 \mathrm{mV}\). After the action potential has passed the neuron returns back to its resting state i.e at \(-70 \mathrm{mV}\).
284553
Which of the following statements characterizes the depolarization state of neuron ?
1 \(\mathrm{Na}^{+}\)gets inside through ion channels
2 \(\mathrm{Na}^{+}\)gets outside through channels
3 \(\mathrm{K}^{+}\)channels remain open
4 All of the above
Explanation:
A During the depolarization of neuron, sodium ion \(\left(\mathrm{Na}^{+}\right)\)gets inside through ion channels. In the resting state of a neuron, the inside of the cell is negative relative to the outside. This is because there are more negatively charged ions (such as chloride ions) inside the cell than outside of the cell. When a neuron is depolarized, the inside of the cell becomes less negative than outside. This because sodium ions \(\left(\mathrm{Na}^{+}\right)\)move into the cell through voltage- gated sodium channels.
UP CPMT-2012
Neural Control and Coordination
284554
During the propagation of a nerve impute, the action potential results from the movement of
1 \(\mathrm{K}^{+}\)ions from extracellular fluid to intracellular fluid
2 \(\mathrm{Na}^{+}\)ions from intracellular fluid extracellular fluid
3 \(\mathrm{K}^{+}\)ions from intracellular fluid to extracellular fluid
4 \(\mathrm{Na}^{+}\)ions from extracellular fluid to intracellular fluid
Explanation:
D During the propagation of a nerve impulse, the action potential results from the movement of sodium ions \(\left(\mathrm{Na}^{+}\right)\)from the extracellular fluid to the intracellular fluid. This influx of sodium ions causes the membrane potential to depolarize, or become more positive. Once the membrane potential reaches a threshold-level, voltage-gated sodium channel open and allow even more sodium ions to enter the cell. This rapid influx of sodium ions creates an action potential, which is a wave of depolarization that travels down the axon of the neuron.
BHU PMT (Screening)-2010
Neural Control and Coordination
284555
An investigator places an isolated neuron in a calcium-free medium, gives the neuron a suprathreshold stimulus and then performs an assay to test whether neurotransmitter is released into the medium. Which of the following outcomes would you predict?
1 No neurotransmitter is detected since influx of calcium into the synaptic knob is required for neurotransmitter release
2 No neurotransmitter is detected since influx of calcium is required in order for the neuron to conduct an action potential
3 Neurotransmitter is detected since calcium is not required for action potential conduction and the initial stimulus was suprathreshold
4 We cannot predict the outcome without knowing whether the neuron was myelinated
Explanation:
A In this given reason, no neurotransmitter is detected since the influx of calcium in to the synaptic knob is required for neurotransmitter release. \(\mathrm{Ca}^{2+}\) triggers synaptic vesicle exocytosis, thereby releasing the neurotransmitters contained in the vesicles and initiating synaptic transmission.
J and K CET-2012
Neural Control and Coordination
284556
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge?
1 First negative, then positive and again back to negative
2 First positive, then negative and continue to be negative
3 First negative, then positive and continue to be positive
4 First positive, then negative and again back to positive
Explanation:
A Before the generation of an action potential, the neuron is in resting state that is \(-70 \mathrm{mV}\), inside the cell. During action potential as transmission of nerve impulse the membrane potential inside the neuron rises up to \(30 \mathrm{mV}\). After the action potential has passed the neuron returns back to its resting state i.e at \(-70 \mathrm{mV}\).
284553
Which of the following statements characterizes the depolarization state of neuron ?
1 \(\mathrm{Na}^{+}\)gets inside through ion channels
2 \(\mathrm{Na}^{+}\)gets outside through channels
3 \(\mathrm{K}^{+}\)channels remain open
4 All of the above
Explanation:
A During the depolarization of neuron, sodium ion \(\left(\mathrm{Na}^{+}\right)\)gets inside through ion channels. In the resting state of a neuron, the inside of the cell is negative relative to the outside. This is because there are more negatively charged ions (such as chloride ions) inside the cell than outside of the cell. When a neuron is depolarized, the inside of the cell becomes less negative than outside. This because sodium ions \(\left(\mathrm{Na}^{+}\right)\)move into the cell through voltage- gated sodium channels.
UP CPMT-2012
Neural Control and Coordination
284554
During the propagation of a nerve impute, the action potential results from the movement of
1 \(\mathrm{K}^{+}\)ions from extracellular fluid to intracellular fluid
2 \(\mathrm{Na}^{+}\)ions from intracellular fluid extracellular fluid
3 \(\mathrm{K}^{+}\)ions from intracellular fluid to extracellular fluid
4 \(\mathrm{Na}^{+}\)ions from extracellular fluid to intracellular fluid
Explanation:
D During the propagation of a nerve impulse, the action potential results from the movement of sodium ions \(\left(\mathrm{Na}^{+}\right)\)from the extracellular fluid to the intracellular fluid. This influx of sodium ions causes the membrane potential to depolarize, or become more positive. Once the membrane potential reaches a threshold-level, voltage-gated sodium channel open and allow even more sodium ions to enter the cell. This rapid influx of sodium ions creates an action potential, which is a wave of depolarization that travels down the axon of the neuron.
BHU PMT (Screening)-2010
Neural Control and Coordination
284555
An investigator places an isolated neuron in a calcium-free medium, gives the neuron a suprathreshold stimulus and then performs an assay to test whether neurotransmitter is released into the medium. Which of the following outcomes would you predict?
1 No neurotransmitter is detected since influx of calcium into the synaptic knob is required for neurotransmitter release
2 No neurotransmitter is detected since influx of calcium is required in order for the neuron to conduct an action potential
3 Neurotransmitter is detected since calcium is not required for action potential conduction and the initial stimulus was suprathreshold
4 We cannot predict the outcome without knowing whether the neuron was myelinated
Explanation:
A In this given reason, no neurotransmitter is detected since the influx of calcium in to the synaptic knob is required for neurotransmitter release. \(\mathrm{Ca}^{2+}\) triggers synaptic vesicle exocytosis, thereby releasing the neurotransmitters contained in the vesicles and initiating synaptic transmission.
J and K CET-2012
Neural Control and Coordination
284556
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge?
1 First negative, then positive and again back to negative
2 First positive, then negative and continue to be negative
3 First negative, then positive and continue to be positive
4 First positive, then negative and again back to positive
Explanation:
A Before the generation of an action potential, the neuron is in resting state that is \(-70 \mathrm{mV}\), inside the cell. During action potential as transmission of nerve impulse the membrane potential inside the neuron rises up to \(30 \mathrm{mV}\). After the action potential has passed the neuron returns back to its resting state i.e at \(-70 \mathrm{mV}\).
284553
Which of the following statements characterizes the depolarization state of neuron ?
1 \(\mathrm{Na}^{+}\)gets inside through ion channels
2 \(\mathrm{Na}^{+}\)gets outside through channels
3 \(\mathrm{K}^{+}\)channels remain open
4 All of the above
Explanation:
A During the depolarization of neuron, sodium ion \(\left(\mathrm{Na}^{+}\right)\)gets inside through ion channels. In the resting state of a neuron, the inside of the cell is negative relative to the outside. This is because there are more negatively charged ions (such as chloride ions) inside the cell than outside of the cell. When a neuron is depolarized, the inside of the cell becomes less negative than outside. This because sodium ions \(\left(\mathrm{Na}^{+}\right)\)move into the cell through voltage- gated sodium channels.
UP CPMT-2012
Neural Control and Coordination
284554
During the propagation of a nerve impute, the action potential results from the movement of
1 \(\mathrm{K}^{+}\)ions from extracellular fluid to intracellular fluid
2 \(\mathrm{Na}^{+}\)ions from intracellular fluid extracellular fluid
3 \(\mathrm{K}^{+}\)ions from intracellular fluid to extracellular fluid
4 \(\mathrm{Na}^{+}\)ions from extracellular fluid to intracellular fluid
Explanation:
D During the propagation of a nerve impulse, the action potential results from the movement of sodium ions \(\left(\mathrm{Na}^{+}\right)\)from the extracellular fluid to the intracellular fluid. This influx of sodium ions causes the membrane potential to depolarize, or become more positive. Once the membrane potential reaches a threshold-level, voltage-gated sodium channel open and allow even more sodium ions to enter the cell. This rapid influx of sodium ions creates an action potential, which is a wave of depolarization that travels down the axon of the neuron.
BHU PMT (Screening)-2010
Neural Control and Coordination
284555
An investigator places an isolated neuron in a calcium-free medium, gives the neuron a suprathreshold stimulus and then performs an assay to test whether neurotransmitter is released into the medium. Which of the following outcomes would you predict?
1 No neurotransmitter is detected since influx of calcium into the synaptic knob is required for neurotransmitter release
2 No neurotransmitter is detected since influx of calcium is required in order for the neuron to conduct an action potential
3 Neurotransmitter is detected since calcium is not required for action potential conduction and the initial stimulus was suprathreshold
4 We cannot predict the outcome without knowing whether the neuron was myelinated
Explanation:
A In this given reason, no neurotransmitter is detected since the influx of calcium in to the synaptic knob is required for neurotransmitter release. \(\mathrm{Ca}^{2+}\) triggers synaptic vesicle exocytosis, thereby releasing the neurotransmitters contained in the vesicles and initiating synaptic transmission.
J and K CET-2012
Neural Control and Coordination
284556
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge?
1 First negative, then positive and again back to negative
2 First positive, then negative and continue to be negative
3 First negative, then positive and continue to be positive
4 First positive, then negative and again back to positive
Explanation:
A Before the generation of an action potential, the neuron is in resting state that is \(-70 \mathrm{mV}\), inside the cell. During action potential as transmission of nerve impulse the membrane potential inside the neuron rises up to \(30 \mathrm{mV}\). After the action potential has passed the neuron returns back to its resting state i.e at \(-70 \mathrm{mV}\).
