Q. No.The resting membrane potential is first established because of:
1. the movement of potassium ions down their electrical gradient through leak channels
2. the opening of voltage-gated sodium channels
3. the action of the Na+/K+ ATPase pump which transports positive ions in unequal numbers
4. the movement of sodium ions against their concentration gradient through leak channels
1. the movement of potassium ions down their electrical gradient through leak channels
2. the opening of voltage-gated sodium channels
3. the action of the Na+/K+ ATPase pump which transports positive ions in unequal numbers
4. the movement of sodium ions against their concentration gradient through leak channels
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
What is true for the events that occur during the generation of an action potential?
1. Potassium channels in the membrane open in response to depolarization
2. Sodium channels in the membrane open in response to neurotransmitter released from the adjacent membrane
3. The increase in sodium permeability in the membrane is an example of positive feedback
4. The movement of sodium into the neuron causes the cell to hyperpolarize
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
Threshold stimuli are those that are strong enough to:
1. Hyperpolarize the neuron membrane
2. Cause a net flux of negatively charged ions from inside to outside the cell
3. Cause a net flux of positively charged ions from outside to inside the cell
4. Close calcium channels to retain them in the cell
The period of time during which a second action potential cannot be initiated, no matter how large the applied stimulus is the absolute refractory period. Which statement is true for this period?
1. Potassium channels are open and the membrane is hyperpolarized
2. It immediately follows the relative refractory period
3. It allows an action potential to proceed in two directions along the length of an axon
4. It occurs when the sodium channels are open
All the following statements with respect to the propagation of action potentials are correct except:
1. Saltatory conduction occurs in myelinated nerve fibers
2. During conduction of an action potential, current flows from the active area of the membrane to the adjacent inactive area, thereby decreasing the potential in the inactive area to the threshold
3. Action potential propagation is faster in myelinated fibers than in unmyelinated ones
4. Action potential propagation is faster for strong stimuli than for weaker stimuli
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
An Inhibitory Post-Synaptic Potential:
1. causes depolarization
2. is caused by an increase in the permeability of the postsynaptic membrane to potassium or chloride ions
3. causes repolarization
4. is caused by an increase in the permeability of the postsynaptic membrane to sodium ions
Common inhibitory neurotrnasmitters in brain and spinal cord are:
1. Glutamate
2. GABA (gamma-amino-butyric aci4.
3. Glutamate and glycine
4. GABA (gamma-amino-butyric acid and glycine
The blood–brain barrier (BBB) separates the circulating blood from the brain and extracellular fluid in the central nervous system (CNS) and:
1. Functions to control the exchange of substances between blood and the extracellular fluid in the CNS
2. Is comprised of the cells that line the largest blood vessels in the brain
3. Is comprised of the cells that line the ventricles of the brain
4. Prevents diffusion of lipid soluble molecules from the blood to the brain
In the peripheral nervous system, the cells that are capable of forming a regeneration tube through which a severed peripheral axon can regrow are the:
1. Schwann cells
2. astrocytes
3. oligodendrocytes
4. microglia
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
The relatively static membrane potential of quiescent cells is called the:
| 1. | action potential | 2. | threshold potential |
| 3. | resting membrane potential | 4. | graded potential |
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.
© 2024 GoodEd Technologies Pvt. Ltd.