Block nerve: location, function, lesions

Everyone from the school knows about 12 pairs of cranial nerves. They occupy key positions in the functioning of the nervous system. Any violation in their work entails a disruption of the work of the whole organism. So the nerve block belongs to the fourth pair.

Location in the brain

It is difficult without anatomical preparations to understand what and where is located. Therefore, it is required to read a detailed description of the location of the nerves. So, the fourth pair is the only one that goes to the back of the brainstem. At the level of the lower hillocks of the roof of the midbrain, nuclei of the nerve block are located. If viewed in the forward direction, then they are located forward from the central gray matter. In relation to the nuclei of the oculomotor nerve, the nuclei of the nerve are located below.

The nerve block forms a cross on a gray plate, called the brain sail, which forms the ventricle cap. After the nerve leaves through the middle brain to the bottom of the lower hills. Each pair bends the leg of the brain from the side. There, the nerve block penetrates into the gap between the temporal lobe of the cerebral hemisphere and the brain stem. Then, moving forward, it penetrates the cerebral cortex into the outer wall of the cavernous sinus. There, through the upper orbital slot reaches the orbit and goes to the upper oblique muscle of the eye.

Block nerve: function, interaction with other pairs of nerves

The main task of the fourth pair of cranial nerves is to keep the eye moving forward and downward. Normally, the eyeball has several axes of rotation. In total, six muscles are involved in this process. So they distinguish the turning of the eye to the temples, to the nose, lifting up and lowering down. An important feature of the human eye is a joint movement, as a person can not normally look with eyes in different directions. Thus, the oculomotor, block and discharge nerves are included in the general group of the oculomotor nerves. Failure in the work of any participant causes visual impairment. Thus, we can draw the following conclusions:

• Isolated eye movements are impossible;
• Both eyes move simultaneously;
• The pair of oculomotor muscles is always shortened.

Research Methodology

To determine whether a particular pair of cranial nerves is functioning correctly, doctors use special methods of investigation. To do this, check whether a person has a double vision in his eyes. The width of the eye slits, the size of the pupil, and the position of the eyeball are carefully studied. An important diagnostic test is the pupil's response to light. For this, the patient is asked to close his eyes with his hands and sharply remove them by looking at the light. To study the convergence of the eyes, use a conventional hammer. He is approached to the bridge of his nose, checking the convergence of apples. The accommodation is tested even easier: the patient closes the eye, the second looks first at the distant object, then at the nearest one.

Block nerve injury: symptoms and treatment

Since the main function of the fourth pair of cranial nerves is motor, the first and the main symptom is paralysis. There is a deviation of the eyeball up and inside. This is clearly seen when the patient walks up the stairs. Another symptom is double vision, as the out-of-sync forces the image to be projected onto different parts of the retina.

When all the oculomotor nerves are affected, the following pattern is observed: the eye does not move, the pupil is wide, does not respond to light. If the same is observed in both eyes, then we can talk about the defeat of the nuclei of nerves.

Most often this is a consequence of the development of such diseases as neurosyphilis, meningitis, an aneurysm, thrombosis and others. Therefore, for treatment it is important to eliminate the root cause of the condition.

To date, there are no effective methods for treating oculomotor nerves. According to the data, physiotherapy is successfully used, its only drawback is a slow effect or its complete absence. In order that the nerve block again began to function, electrostimulation is often used.

In any case, treatment should only be done by a doctor. When lesion of cranial pairs of nerves is better to use a comprehensive approach, which includes several techniques. It is important not to start the process of the disease, since the development of the defeat of the nuclei of nerves, which at times reduces the chances of recovery.