Cranial-cerebral nerves, abnormalities arising from their pathology

The nervous system includes the spinal cord and the brain, the nerves that drain from them and their branches. All nerve branchings are connected to the peripheral nervous system. There are 12 pairs of cranial nerves and 31 pairs of spinal nerves. Each pair has its own name and number, which is denoted by a Roman numeral. Cranial nerves are located in the base of the brain. According to the composition of nerve fibers, three of their functions are distinguished: motor, sensory and mixed.

Sensitive cranial nerves are formed from fibers of neurons that lie outside the brain. These include the olfactory, visual and auditory nerves. They provide vestibular function, hearing, sight and smell. The first pair begins with nerve cells that are located in the nasal mucosa. With the defeat of this nerve, there is a complete loss of the ability to smell. The second pair is the optic nerve, which originates in the cells of the retina. His atrophy leads to a sharp decrease in visual acuity, sometimes to complete blindness. The eighth auditory pair of nerves is responsible for the hearing and activity of the vestibular apparatus. If his work is disturbed, dizziness, deafness, ataxia, vestibular dysfunction occur.

The motor function combines five pairs of nerves. They originate in the motor nuclei of the trunk. The third, fourth and sixth pair of nerves are associated with the device and the movement of the eyes. The oculomotor nerve is the third pair. It is formed by fibers starting from the same nuclei. Parasympathetic fibers contained in this nerve innervate the musculature of the eye. The injured cranial nerves of the third pair are characterized by the descent of the upper eyelid, the divergent strabismus, and the dilatation of the pupil. When the IV block nerve is damaged, the vision of objects is noted in vision. When the sight is lowered down, a small squint appears. If the activity of the VI nerve is disrupted, the movement of the eyeball changes outward, this leads to a converging strabismus and double vision.

The facial nerve (VII) controls mimic muscles. In addition, it contains taste sensory fibers and has vegetative fibers that regulate the function of the salivary and glandular glands. The additional XI nerve regulates the functions of certain types of muscles. When it is damaged, there is paresis of the muscles or paralysis. The last, sublingual XII nerve, is connected with the muscles of the tongue. If the activity of this nerve is disturbed, there is a restriction of the mobility of the tongue forward and its deviation to the diseased side. There is atrophy of muscles, pain of the root of the tongue, fibrillar twitchings.

Mixed functions of cranial nerves perform V, IX, and X pairs. The fifth, triple nerve controls the chewing muscles and provides the sensitivity of the face. The glossopharyngeal (IX) nerve is responsible for salivation, taste and for the state of pharynx and tongue. The wandering (X) nerve provides sensitivity to the posterior parts of the oral cavity, larynx and pharynx. He is responsible for the functioning of their muscles. Cranial nerves of the X pair provide a parasympathetic interrelation of the internal organs.

In the defeat of the trigeminal nerve, there are attacks of severe pains of a neurological nature in the corresponding areas of the face. They are accompanied by redness and lacrimation. With the pathology of the IX pair, pains in the pharynx are felt, there is difficulty in swallowing, a disorder of taste is noticed, salivation is disturbed. With the defeat of the vagus nerve, there are deviations in the activity of internal organs. With bilateral damage, there is a disorder of swallowing, nasal hue of speech, pain in the auricle. Such violations are always accompanied by a heavy forecast.