EMBRYOLOGY
NERVOUS SYSTEM
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
How much the voltage is the threshold to action which will be responded?
|
|
-70mV
|
|
|
-55mV
|
|
|
Either A or B
|
|
|
None of the above
|
Explanation:
Detailed explanation-1: -The channels that start depolarizing the membrane because of a stimulus help the cell to depolarize from-70 mV to-55 mV. Once the membrane reaches that voltage, the voltage-gated Na+ channels open.
Detailed explanation-2: -Action potentials are triggered when an initial depolarization reaches threshold. This threshold potential varies, but generally is about 15 millivolts above the cell’s resting membrane potential, occurring when the inward sodium current exceeds the outward potassium current.
Detailed explanation-3: -Threshold of excitation(threshold): The level that a depolarization must reach for an action potential to occur. In most neurons the threshold is around-55mV to-65mV.
There is 1 question to complete.