Question

Why is the membrane of a neuron polarised?

Answer 1

Part 1: Polarised Neuron
The phase where there is no stimulus is called the resting phase of the neuron. During this phase the axonal membrane is more permeable to potassium ions and the concentration of potassium ions is more in the axoplasm. Thus the potassium ions move from the higher concentration ( axoplasm) region to the lower concentration region (outside the axonal membrane). Since the axoplasm loses its positive ions, it becomes more negatively charged and outside the axonal membrane becomes positively charged. This state of the axonal membrane is called the polarised state. The process is called polarization of the membrane of a nerve fiber. Thus in the resting phase the axonal membrane is said to be polarised.