- Exam
- NEET
- Subject
- Zoology
- Chapter
- Neural Control and Coordination
NEET · Zoology · Neural Control and Coordination
What is the state of the neural membrane when a neuron is not...
Options
- APolarised
- BDepolarised
- CHyperpolarised
- DHypopolarised
Correct answer
A. Polarised
Step-by-step solution
The electrical potential difference across the resting plasma membrane is called the resting potential.The outer surface of the axonal membrane possesses a positive charge while its inner surface becomes negatively charged and therefore is polarised.The membrane of a neuron is polarised due to the presence of different types of ion channels and the ionic gradients maintained by the sodium-potassium pump.
The fluid outside the axon in a resting state contains a low concentration of K⁺, a high concentration of Na⁺ and thus form a concentration gradient.Different types of ion channels are present on the neural membrane, which are selectively permeable to different ions. The sodium-potassium pump transports 3 Na⁺ ions outwards for 2 K⁺ ions into the cell.