PATHOLOGY MCQ
IMMUNE RESPONSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the nodes of Ranvier can conduct potentials only one way
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the refractory period is required to restore ion balance
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the resting potential is more negative down the axon
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voltage-gated Na+ and K+ channels only open in one direction
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Detailed explanation-1: -Second, the action potential can only travel in one direction – from the cell body towards the axon terminal – because a patch of membrane that has just undergone one action potential is in a “refractory period” and cannot undergo another.
Detailed explanation-2: -These transitory changes make it harder for the axon to produce subsequent action potentials during this interval, which is called the refractory period. Thus, the refractory period limits the number of action potentials that a given nerve cell can produce per unit time.
Detailed explanation-3: -The absolute refractory period is important because it creates a limit to how many action potentials, and thus signals can be sent by a neuron. This means that there is an upper limit to the amount of stimuli we can detect and also how fast we can respond to changes in the environment.