WHY AND HOW IS THE MEMBRANE OF NEURON POLARISED - Biology - Neural Control and Coordination

Question

WHY AND HOW IS THE MEMBRANE OF NEURON POLARISED ?

Mushtaq · Accepted Answer

Hi Diwakar,

Please find below the solution to the asked query:

Neurons are excitable cells because their membranes are polarised
Neural membranes are polarised because selectively
permeable ion channels are present on them
In the resting state, the membrane of the nerve cell is more
permeable to the K+ ions and impermeable
to Na +
ions Also only 2 K + ions move inside for 3
Na +
ions to come out of cytoplasm of axon called axoplasm The membrane
of nerve cell is also impermeable to negatively charged proteins
present inside the axoplasm Thus, it does not let them go out As a
result, the axoplasm has more concentration of negatively charged
proteins than positively charged
Na+ and
K+ This
makes the over all charge inside the axoplasm negative and outside
the membrane becomes positive due to more number of
Na+
Hence, the outer surface of the membrane possesses positive charge
and the inner surface possesses negative charge This is known as
polarised membrane

Hope this information will clear your doubts about Polarisation of
membrane
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