Which one of the following elements is needed in the human body to tra

Which one of the following elements is needed in the human body to transfer electrical signals by nerve cells ?

Lithium
Sodium
Rubidium
Caesium
This question was previously asked in
UPSC NDA-1 – 2018
Sodium is an essential element in the human body needed for the transmission of electrical signals by nerve cells.
Nerve impulses, or action potentials, are electrical signals that travel along nerve cells. This process involves the rapid movement of ions, particularly sodium (Na⁺) and potassium (K⁺), across the nerve cell membrane through specific ion channels. The differential concentrations of these ions across the membrane create an electrochemical gradient, which, when disturbed, generates the electrical signal. Sodium ions play a critical role in the depolarization phase of the action potential.
While potassium is also crucial for nerve signalling (repolarization), sodium is listed as an option and is fundamental to the process. Calcium ions (Ca²⁺) are also involved in neurotransmitter release at nerve synapses.