How many pairs of cranial nerves arise from the human brain?

Twelve pairs of cranial nerves arise from the human brain.

Cranial nerves are numbered with Roman numerals I through XII. They carry sensory information, motor commands, or both, and most serve structures in the head and neck. The first two, the olfactory and optic nerves, are closely associated with the forebrain, while most of the remaining nerves emerge from the brainstem.

Their functions range from smell, vision, eye movement, facial sensation, hearing, and balance to swallowing, speech, and control of organs in the chest and abdomen. The vagus nerve, cranial nerve X, has especially extensive distribution beyond the head and neck.

The standard human anatomical count is 12 pairs, meaning one nerve on each side for each numbered type. Some anatomical discussions mention a possible thirteenth pair, the terminal nerve, but it is not included in the conventional clinical count. This is why “12 pairs” is the accepted answer in standard anatomy, while individual nerve branches should not be confused with additional cranial-nerve pairs.