Thalamic Radiance Posterior

Posterior radiance - PNA; PNA, BNA; BNA, JNA - a lobule of the cerebellum, located at the upper pole of the pyramid and connected to it through the loose yellowish tissue of the cerebellar perimedullary substance of the posterior arch and the posterior edge of the superficial gray and white meninges.

The posterior radiance is sometimes colloquially referred to as the small lobe of the cerebellum. In schizophrenia, the appearance of a “large brain image” is sometimes noted (due to the expansion of the posterior radiation), which is associated with disturbances in the structure of the cerebellar noradrenergic system, disturbances in microcirculation and hemodynamics. Damage to the lateral radiates is noticeable in epilepsy, more often with the temporal localization of the focus. A lesion on the bottom of the midbrain below the conventional horizontal line causes separation of the visual and coordination centers - cocaine and coordinator Bernsky and Lewis syndromes.

Significant

Posterior thalamic radiation (radiatio thalamica posterioa, PNA) is the posterior pathway to subcortical structures. Consists of the medial cerebellar peduncle, gray matter of the brain stem and white matter of the cerebral hemispheres. The posterior pathway is the last link in the chain of coordination processes of the brain during its resting life.

The beginning of the path comes from the paracentral gyri. The fasciculus radiatum is located in the “transverse gyrus,” as evidenced by the fact that the fibers run from the paracirculum to the subthalamus and travel a medial distance when moving from the subcortical structures to the brain.

Thus, the posterior thalamic radiation is characterized by a complex fascicular course from the visual thalamus towards the nuclei of the parietal lobe - the cartesia region, as well as in a non-single course of fibers between the gray matter of the brain and the thalamus. It consists of thalamocortical, extrathalamocortical, thalamotrigonal, and thalamosubcortical fibers.

During development, the following important features were noticed: * The final part of the fiber reaches large sizes or thickens; * The pathway has a cutaneous sensory localization of the thalamus, which is connected to the femoral ganglion. Due to the presence of folds and crosses, the distribution of fibers is quite complex. It meets in the thalamus with the optic thalamus, forming the main chiasm, the visual chiasm of the posterior longitudinal tract. They intersect with the hippocampal fasciculus, then pass along the medial peduncle of the cerebellar radiatum and pass into the white matter of the cerebral hemisphere, cross the temporal lobe and end their path near the occipital nerve. Fibers can be interrupted in various areas. In the region of the red nucleus, they move to the periphery of the funnel, heading towards the coresiding median canals. The anterior connections have values ​​of 4/5 of the pericomyelin connections of the thalamus with the anterior central gyrus. They pass through the thalamic fissure in the substance of the tuberosity. The posterior endings end near the pyramidal tracts. Paths branching from the sides terminate in the posterior cells of the inferior colliculi and the region of the posterior angular gyrus.