Medulla (medulla oblongata) is shaped like an onion. On its front surface, front side of the median gap (fissura mediana anterior are the way of conscious motor impulses, which are called pyramid (pyramis). Pyramid formed by the pyramidal tract (tractus pyramidalis). They are located at the side of the olive (oliva), which contain the subcortical nucleus of equilibrium, and in deepening the roots between the olive trees are the hypoglossal nerve (XII pair) bound to the muscles of the language. Pyramids and olives are separated by the anterior lateral sulcus (sulcus lateralis anterior). Olives are formed by nerve fibers and gray matter, which forms the core of olives (nucleus olivaris). At the core of isolated gate (hilus nuclei olivaris) formed olivomozzhechkovym tract (tractus olivocerebellaris).
Side of the olives are sent down the fiber of glossopharyngeal nerve (IX pair) that innervate the region of the pharynx and tongue, the vagus nerve (X pair) that innervate the large area of ??the chest and abdomen, and accessory nerve (XI pair), penetrating to the trapezius and sternomastoid muscles.
The back of the pair are thin (fasciculus gracilis) and sphenoid (fasciculus cuneatus) beams of the same name bound to the tubercles and represents a continuation of posterior spinal cords. In this case a thin beam lies medially, and the wedge-shaped - laterally. Free triangular section back surface participates in the formation of rhomboid fossa. On the lateral area of the triangle are the nucleus IX and X pairs of cranial nerves, so he called the triangle of the vagus nerve. The medial area of the triangle contains a projection of the hypoglossal nerve nucleus is called the triangle of the hypoglossal nerve.
|In Fig. 259.
1 - olivomozzhechkovy tract;
2 - core olives;
3 - Gate of olive kernel;
4 - olive;
5 - the pyramidal tract;
6 - hypoglossal nerve;
7 - a pyramid;
8 - Front lateral sulcus;
9 - nerve extension
Hypoglossal nerve fibers, go to the thickness of the medulla oblongata and are clearly visible in cross section. Hypoglossal nerve divides the diameter of the side sections and the middle sections, where is the conductor device, the beams which form a pyramid. Posterior to the pyramids lie conductors joint-muscular sense, which are outgrowths of cells forming a thin and wedge-shaped nucleus. Spines directed upward, crossed with each other and are called the medial fibers of the loop. The side sections contain nuclei olive, with jagged shape, and fiber, sinking below the feet of the cerebellum and connecting it with the medulla. Vestibular nuclei (VIII pair), cranial nerves (IX and X of the pair) and diffusely scattered neurons of the reticular formation on the cut is not visible, but also found in the lateral parts. They are responsible for reflex functions such as reflex balance, swallowing, sucking, respiratory and cardiovascular reflexes, as well as protective (coughing, sneezing, etc.).
a., aa. — arteria, arteriae (artery, the artery)
lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)
m., mm. — musculus, musculi (muscle, the muscle)
n., nn. — nervus, nervi (nerve, the nerve)
r., rr. — ramus, rami (branch)
s. — seu (or)
v., vv. — vena, venae (vienna)