2. Write a paragraph of 3-5 sentences answering the following questions. Your re

Question

2. Write a paragraph of 3-5 sentences answering the following questions. Your response should first answer the question and then go onto state physiological interpretation's behind your answer. Paragraphs that demonstrate complete and thorough reasoning will receive full points.

You discover a drug that prevents voltage-gated Na+ channel inactivation gates from opening when they are closed but has no effect on inactivation gates when they are open. What would happen to the action potential in a neuron exposed to this drug? Explain your answer. Assume the neuron is at resting membrane potential (e.g., -70 mV) at the time it is exposed to the drug.

Explanation / Answer

sodium channel is integralmembrane protiens that from ion channels ,conducting sodium ions through a cellls plasma membrane . They belong to superfamily of cation channels and can be classified according to the trigger that opens the channel for such ions i.e either a voltage change or a binding of a substance to the channel.in excitable cells such as neurons ,myocytes,and certain types of glia, sodium channels are responsible for raising phase of action potentials.These channels go through 3 different states called as resting ,active, inactive states.

sodium channels comsist of large alpha subunits that associate with protiens such a beta subunits .an alpha subunits from core of channels and is funtional on its own.when the alpha subunit protien is expressed by a cell, it is able to form channels that conducts sodium in a voltage gated way,even if beta subunits or other known modulating protiens are not expressed.

Before an actionn potential occurs,the axonal membrane is at its normal resting potential, and sodium channels are in theirs deactivated state,blocked on the extracellular side by their acctivation gates.

At the peak of action potential ,when enough sodium has entered the neuron and the membranes potential has become high enough the sodium channels inactive themselves by closing their inactivation gates.

when membrane voltage becomes ow enoug the inavtivation gate response and the activation gate reopens and the activation gets closes in a process called deactivation.

AN action potential is a transient electrical signal,which is caused by rapid change in resting membrane potential (-70mV).this occurs when the threshold potential (-55mV) is reached ,this causes a raoid opening in the voltage gated sodium channels leading to an influx of sodium ions into the cell..

The neuron goes from a polarized state at the resting potential with the neuron moree negatively charged inside than outside the membrane to a depolarized state during the action potantial with the cell positevely charged on inside.

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.