Fill in the blanks. Choose the appropriate word or words from the brackets and fill up the blanks:

(a) Messages take the form of electrical signals and are known as ____.(nerves/impulses)

Nerve impulses:

1. Messages are carried by neurons in the form of electrical signals which are transmitted to the adjacent neurons.
2. It is also called an action potential.
3. These impulses are caused due to the movement of the sodium and potassium ions across the membrane.
4. The sodium-potassium pump maintains the unequal distribution of the ions across the membrane creating an electrical activity.