Cranial nerves

Cranial nerves or cranial pairs are a set of 12 pairs of nerves that arise directly from the brain. The first two olfactory and optic nerves arise from the brain, while the remaining ten arise from the brainstem. The names of the cranial nerves are related to their function and are also identified numerically in Roman numerals ranging from I to XII.

What are cranial nerves?

Cranial nerves are the nerves located at the base of the skull that allow us and facilitate us to perform all our basic functions of both, muscles and viscera that make up the human body.

The cranial nerves are numbered by their location in the brainstem whether superior to inferior, then medial to lateral and the order of their exit from the skull which may be anterior to posterior.

Which are the cranial nerves?

The cranial nerves are as follows:

Function of cranial nerves

The function of the cranial nerves goes according to each cranial pair. In this way, we can say that the functions are:

Real and apparent origin

Each skull pair has a real and an apparent origin. The apparent origin is the place of emergence of the nerves through the encephalic mass and the real origin is the place where the nerve fibers that make up the nerve originate.

Classification of cranial nerves

Cranial nerves can be classified into:


The sensitive nuclei are the somatic afferents and the visceral ones. They include all the sensitive parts that a cranial pair has in the nerve cells which form prolongations, thus creating first-degree neurons, second-degree neurons and third-degree neurons in which the axons end up in the cerebral cortex.


The disorders that occur in them can affect taste, sight, facial sensitivity, facial expressions, hearing, speech and balance, even some of them can affect the muscles of the neck. Some of the pathologies that can occur in the cranial nerves are the following:

Exploration of cranial nerves

The scan is performed to determine the presence of a disease affecting the cranial nerves. Some of the methods are:

Written by Gabriela Briceño V.

How to cite this article?

Briceño V., Gabriela. (2019). Cranial nerves. Recovered on 16 April, 2021, de Euston96:

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