12 pairs of cranial nerves: the table. Cranial nerves: distribution and brief characteristics

Nerves, departing from and entering the brain, are called cranial nerves. The distribution and a brief description of them are considered separately in the next article.

Types of nerves and pathologies

There are several types of nerves:

• Motor;
• Mixed;
• Sensitive.

Neurology of the motor craniocerebral nerves, both sensitive and mixed, has pronounced manifestations, which specialists can easily diagnose. In addition to the isolated lesion of individual nerves, those that belong to different groups can also be affected. Thanks to the knowledge of their location and functions, it is possible not only to understand which nerve is disturbed, but also to localize the affected area. This becomes achievable through special techniques with the use of high-tech equipment. For example, in ophthalmic practice, using modern technology, it is possible to know the condition of the fundus, optic nerve, determine the field of vision and foci of loss.

Not bad values reveals carotid and vertebular angiography. But more detailed information can be obtained with the help of computed tomography. With it you can see individual trunks of nerves and reveal tumors and other changes in the auditory, visual and other nerves.

To study the trigeminal and auditory nerves became possible due to the method of cortical somatosensory potentials. Also in this case, use audioography and nystagmography.

The development of electromyography has expanded the possibilities for obtaining more detailed information on cranial nerves. Now you can explore, for example, a reflex blinking response, spontaneous muscle activity in mimicry and chewing, muscles of the tongue, the sky and so on.

Let us dwell in more detail on each of the pairs of these nerves. In total there are 12 pairs of cranial nerves. The table, where all of them are given, is listed at the end of the article. In the meantime, consider each of the pairs separately.

1 pair. Description

This includes the olfactory nerve of the sensitive group. In this case, the receptor cells are scattered in the epithelium of the nasal cavity in the olfactory part. Thin nerve cell processes are concentrated in olfactory threads, which are olfactory nerves. From the nasal nerve enters the cavity of the skull through the holes of the plate of the latticed bone, and ends in the bulb, from which the central olfactory pathway begins.

2 pair. The optic nerve

This pair includes the optic nerve, which belongs to the sensitive group. The axons of the neurons here come out through the trellis plate from the eyeball with one trunk that enters the cranial cavity. At the base of the brain, the fibers of these nerves converge on both sides and create visual crossover and tracts. The tracts go to the elbow and thalamus pillows, after which the central visual pathway is directed toward the occipital lobe of the brain.

3 pair. Motor nerve

The oculomotor (motor), the nerve created by the fibers, passes from those nerves that are in the gray matter under the brain drainage. To the base, it passes between the legs, then it enters the orbit and innervates the eye muscles (except for the upper oblique and external straight line, for their innervation there are other cranial nerves, 12 pairs, the table with which clearly illustrates all of them together). This is due to the parasympathetic fibers contained in the nerve.

4 pair. The nerve block

This pair includes the nerve block (motor), which originates from the core under the brain drain and emerges to the surface in the area of the brain sail. In this part, you get a crosshair, bending the leg and penetrating the orbit. This pair innervates the upper oblique muscle.

5 pairs of 12 pairs of cranial nerves

The table continues with the trigeminal nerve, which is already related to the mixed nerves. In its trunk there are sensitive and motor nuclei, and on the base - their roots and branches. Sensitive fibers originate from the cells of the trigeminal node, whose dendrites create peripheral branches innervating the skin of the scalp in front, as well as the face, the gums with teeth, the eye conjunctiva, the mucous membranes of the nose, mouth, and tongue.
The motor fibers (from the spine of the trigeminal nerve) connect with the mandibular nervous branch, pass and innervate the masticatory muscles.

6 pair. Abduction nerve

The next pair of craniocerebral nerves entering the 12 (the table relates it to the group of motor nerves), the pair includes the abducent nerve. It starts from the cell nuclei in the variolic bridge, penetrates the base and moves forward to the orbital fissure on top and further to the orbit. It innervates the direct eye muscle (external).

7 pair. Facial nerve

This pair consists of the facial nerve (motor), created from the cellular processes of the motor nucleus. Fibers begin their way in the trunk at the bottom of the fourth ventricle, pass around the nucleus of the fourth nerve, descend to the base and exit into the bridge-cerebellar angle. Then it moves to the auditory opening, into the channel of the facial nerve. After the parotid gland, it is divided into branches innervating the facial mimic and muscles, as well as a number of others. In addition, one branch that branches from its trunk innervates the muscle located in the middle ear.

8 pair. Auditory nerve

The eighth pair of 12 pairs of cranial nerves (the table reckons it to the sensitive nerves) consists of the auditory, or pre-cochlear nerve, which includes two parts: the vestibule and cochlear. The cochlear part consists of dendrites and axons of the spiral node located in the bone cochlea. And the other part departs from the vestibular node at the bottom of the ear canal. The nerve on both sides is connected in the auditory meatus into the auditory nerve.

Fibers of the vestibule end in those nuclei that are in a diamond-shaped fossa, and cochlear in the cochlear cores of the variolium bridge.

9 pair. Glossopharyngeal nerve

The cranial nerves table continues with the ninth pair, which is represented by the glossopharyngeal nerve. It includes sensitive, motor, secretory and taste fibers. There are close links with the vagus and the intermediate nerves. Many nuclei of the nerve in question are located in the medulla oblongata. They are common with the tenth and twelfth pairs.

Nerve fibers of the pair are combined into a trunk leaving the cranial cavity. For the posterior third of the palate and tongue, it is a tasteful and sensitive nerve, for the inner ear and pharynx - sensitive, for the pharynx - motor, for the parotid gland - secretory.

10 pair. Nervus vagus

Next, the table of cranial nerves continues with a pair consisting of a vagus nerve, which is endowed with different functions. The trunk begins from the roots in the medulla oblongata. Coming out of the cranial cavity, the nerve innervates in the throat the striated muscles, as well as in the larynx, the sky, the trachea, the bronchi and the digestive organs.

Sensitive fibers innervate the occipital region of the brain, the auditory passage from the outside, the rest of the organs. Secretory fibers are sent to the stomach and pancreas, vasomotor - to the vessels, parasympathetic fibers - to the heart.

11 pair. Description of the additional nerve

The additional nerve represented in this pair consists of the upper and lower sections. The first comes out of the motor nucleus of the medulla oblongata, and the second - from the nucleus in the horns of the spinal cord. The roots are connected to each other and come out of the skull together with the tenth pair. Some of them pass to this vagus nerve.

It innervates the muscles - sternocleamus-mastoid and trapezoid.

12 pair

The summary table of cranial nerves with a sublingual nerve pair ends . Its nucleus is located at the bottom of the medulla oblongata. Coming out of the skull, it innervates the lingual muscles.

These are exemplary schemes of 12 pairs of cranial nerves. Let's sum up the aforesaid.

Look at the list of cranial nerves, 12 pairs. The table is as follows.

Conclusion

This is the structure and function of these nerves. Each pair plays its most important role. Each nerve is a part of a huge system and depends on it as well as the whole system - on the functioning of individual nerves.