The stem of the brain (NM) is one of two paired structures that make up the midbrain, which determines its functional purpose and importance.
Almost all chordates have a mesencephalon, which is responsible for performing vital functions that play invaluable role in ensuring vitality, survival, pain regulation and sleep alternation and wakefulness.
He is also responsible for the reflexes of defense, defense, spatial-temporal orientation and even for maintaining a constant body temperature, control of movements and concentration of attention.
Definition of the term
The legs of the midbrain are located in the midbrain space, a small but significant formation, located between the posterior segment and the subcortex.
The mesencephalon, which includes several variable segments, may seem complex in structure, but in fact it is much simpler than the rest of the sections.
The difficulty in learning and memorizing the device can be overcome by the old mnemonic method, in which the department is drawn in a cut, in the form of an inverted the head of a bear, where each base of the leg of the brain is bear ears, and the bodies of the legs in this picture are wide pieces of the muzzle drawn schematically beast:
Communication is achieved thanks to corticospinal fibers passing through the base of the structure, heading to the BP cortex, and on the way back to the spinal tract from the somato- and viscero-sensory regions bark brain.
The anatomical symbol has several variations, including different concepts of the occurrence or separate distance of certain structural and segmental formations, the presence in them of specific, unusual substances or their independent position, in the role of the border between anatomical segments.
| Structure | Definition 1 | Definition 2 |
|---|---|---|
| the part of the brain stem located on top | adjacent to the actual tire | tire is not a separate segment, but part of the general concept of the structure |
| Lower and front parts of the HM | border of NM basal base and operculum are separate parts adjacent to anatomical structures |
the base and cover of the legs are structures separated in the first definition, and in the second are considered an integral part |
| black specific substance | bordering formation between different parts of the midbrain | defined as part of the NM |
If we take for granted the first distinction, in which the anatomical structure is present only as two striated ridges (smoothly coming out from under Varoliyev Bridge and further diverging towards different hemispheres (right and left), everything is extremely simple.
If we assume that the scientific concept includes the lining of the legs of the brain, the base and black matter, which is turned with the convex side towards the base, then this is a complex structure. It is located in no less whimsical and intricate in terms of the presence of various functional devices mesencephalon and is closely related to the rest of the brain due to the specifics of its devices.
Anatomical structure and function
The midbrain is a very small formation, it contains several structures at once and is responsible for many functions, including reproductive. It would be erroneous to assume that the midbrain is made up of cerebral peduncles and a lining. In addition to the base of the NM and black matter, it has a quadruple and a tire. It is formed from a complex midbrain, ventral and dorsal parts.
The main difficulty in considering the anatomical structure is the decision - whether to accept only rollers in it, from of which the legs of the brain are formed, or include in their composition and the lid of the midbrain, the bottom and specific black substance:
- Traditional consideration will not show anything except the body of the legs itself, with a fossa located between them (tarin or inter-peduncle). It is a part of the inter-pectoral cistern, located at the base of the human skull, from where the midbrain receives the cerebrospinal fluid necessary for vital activity.
- In the area of the interperal, there is a nerve outlet that moves the eyeball, eyelid and provides the pupil's response to a light stimulus, and with the outer surface is a trochlear nerve, which cannot be dispensed with in the movement of the oblique muscles and some characteristic turns of the eyes in orbit.
- Black mass, in one interpretation - a delimiting structure, and in another - a component of the current system, develops from the mesencephalon and regulates the coordination of movements. Its remarkable feature is that it is the only region of HCC in which cells are stained with melanin.
- The base of the NM (base of the brain) is nothing more than the lowest part located in front. In the definition of the belonging of this part, there are discrepancies not only in the old textbooks of anatomy, where these terms were considered equivalent or simply were not singled out as a separate entity. Now the ONM is precisely the lower part, in which there are axons stained with myelin.
- In contrast to the base, the lining is located between the substantia nigra and the aqueduct of the brain; it forms both one and the other segment located nearby. Its structures include the red nucleus, its ventral and dorsal parts.
- It also contains a gray (near-aqueduct) substance, which is anatomically classified as a tectum, although it is located next to the aqueduct of the brain. OSV is considered to be the main center for the regulation of the downward pain symptom. It is capable of projecting onto the nuclei of the thalamus and spinal cord, as well as into the nuclei of the suture and the blue spot.
The importance of anatomical education, regardless of its composition in the first or second case, is undeniable. After all, it is precisely this that provides orientation according to the visual picture and the received stimulus, ensures the maintenance of a certain posture of the body and regulation of muscle tone at the reflex level.
The connection of anatomical education with other areas of the brain is carried out in the most variable ways - from the fibers of the corticospinal pathway, going to the most important analyzers (ascending and descending), to the information transmitted by the neurons of all nearby formations of gray, white and black color.
Consequences of injuries to the legs of the human brain
Any damage in this area leads to the development of numerous syndromes described in special literature and even named after the names of the scientists who first recorded the phenomenon for science.
The nature of the manifestations depends on what exactly has undergone destructive changes:
- damage to the oculomotor nerve, depending on the dislocation, gives vertical nystagmus, discoordination or ophthalmoplegia of various kinds (internal total, external), Notnagel's syndrome;
- destruction of the base of the leg leads to paralysis of the oculomotor nerve and destruction of the pyramidal bundle;
- trauma in this area gives cerebellar disorders, loss or disorder of the functionality of the organs of vision and hearing;
- atrophic changes in the legs of the brain can lead to a loss of the ability to respond to external stimuli and can lead to the loss of the ability to independently support life.
With a relatively small size, the midbrain and the structures of control and management located in it play an important role in ensuring the normal functioning of the organs of hearing and vision. They are the control center for sleep and even cerebellar activity. Any type of defeat - trauma, appearance neuroinfections, failure of cerebral circulation, malignant and benign neoplasms will inevitably cause disorders in the activity of the systems for which they are responsible.
Strabismus and discoordination as a result of the pathology of the oculomotor nerve are only a small part of the upcoming complications in which attention disorder, impulsive behavior and hyperactivity, hallucinations, visual and tactile perception deceptions.
Any manifestations of atrophy of brain structures are irreversible, and rarely amenable to final cure.
