Hypoglossal nucleus
The hypoglossal nucleus (Latin core of the hypoglossal nerve ), short Nucl. hypoglossal nerve is a paired -scale cranial nerve nucleus (nucleus, "core" ) in the medulla oblongata (medulla oblongata ), a part of the brain. It consists of nerve cell bodies. Their projections, called axons, the corresponding XII Cranial nerve form. This is referred to as the hypoglossal nerve.
From the left hypoglossal nucleus of the left hypoglossal nerve emerges from the right according to the right hypoglossal nerve. The two XII. Cranial nerves are responsible for the supply ( innervation ) of the entire tongue muscles.
Neuroanatomy
The hypoglossal nerve whose axons have their origin in the corresponding core area, is a pure motor nerve that supplies the muscles of the tongue. The innervation can be arbitrary. It is therefore in the hypoglossal nucleus of a purely somatomotorisches heartland.
The hypoglossal nucleus is located in the rear part of the fourth ventricle, which is the diamond-shaped floor of the fourth ventricle in the region of the brain stem, in the area of Hypoglossusdreieck ( trigone of hypoglossal nerve ). ( Be the part of the brain in the conscious motor movements controlled) to pull the core area of nerve fibers of the motor cortex of mutual ( contralateral ) side of the brain. The outgoing from the mainland of nerve fibers leave the brainstem between pyramid and olive as
The Rami medullares are responsible for the blood supply of the hypoglossal nucleus. These are to branches of the anterior spinal artery, an unpaired vessel that arises from the left and right vertebral artery.
Development
Since the core area is located superficially and centrally located on the brain stem, it is like all other somatomotor nuclei a derivative of the base plate ( system of motor areas in the brain) of embryonic development.
Clinical references
A unilateral damage to the hypoglossal nucleus performs as well as the damage to the associated cranial nerve paralysis of parts of the tongue muscles. The tongue deviates to one side when protruded from the injury (for details, see the article hypoglossal nerve ). The result of the damage to the core area is a washed-out, slurred speech (dysarthria ). In addition, there may be difficulty swallowing. Since both cores are relatively close to each other, damage to both cores is possible.
To damage to the hypoglossal nucleus may be caused by cerebral infarctions due to vascular occlusions. A closure of the supplying the heartland Rami medullares leads to the so-called medial medulla oblongata - syndrome ( Dejerine syndrome). Even with other rare brainstem syndromes participation of this core area is typical, for example, when Tapia and the Schmidt syndrome.