The above depolarization of a neuron will result in which of the following ionic currents? a potassium current will transport K+ ions out of the cytoplasm a sodium current will transport Na+ ions out of the cytoplasm a potassium current will transport K+ ions into the cytoplasm a sodium current will transport K+ ions out of the cytoplasm E. a sodium current will transport Na+ ions into the cytoplasm
The above depolarization of a neuron will result in which of the following ionic currents?
- a potassium current will transport K+ ions out of the cytoplasm
- a sodium current will transport Na+ ions out of the cytoplasm
- a potassium current will transport K+ ions into the cytoplasm
- a sodium current will transport K+ ions out of the cytoplasm
E. a sodium current will transport Na+ ions into the cytoplasm
Action potential or an electrical impulse is another name for a nerve impulse. In contrast to a resting potential, the action potential propagates along the membrane from one point of the neuron to another. It is the only way in which the information is transferred to a long distance by the nervous system.
Answer: Option E. “a sodium current will transport Na+ ions into the cytoplasm”
The axon of the neuron contains voltage-sensitive in channels that open and close sequentially once the threshold has been reached. These voltage-sensitive ion channels are responsible for an action potential. An action potential can be summarized as a sequence of three events, such as, depolarization, repolarization, and the subsequent reestablishment of the resting potential.
Depolarization occurs when membrane potential exceeds the threshold value. This briefly opens voltage-sensitive Na+ channels in the axon membrane and Na+ from the surrounding interstitial fluid rapidly diffuses into the cytoplasm of the axon. This influx of positive Na+ shifts the membrane potential from a negative value of -70 mV to a positive value of about +30 mV. Therefore, the option E is correct.
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