Ambiguous Nucleus

AMBIGUOUS NUCLEUS, enters into the composition of the anterior nucleus of the vagus nerve, lies in the reticular formation of the lateral column of the medulla oblongata (see the figure on p. 296), in the lower parts of which it appears before the opening of the central canal into the fourth ventricle. This nucleus is considered to be a separated part of the anterior horn and is formed by cells resembling the motor cells of the spinal cord. The axons of these cells are directed backward and outward and connect with other fibers of the vagus nerve. Near the ambiguous nucleus, the sensory fibers of the same side branch off from the substantia gelatinosa Rolandi, from the formatio reticularis, and the motor fibers of the opposite side (fibrae cortico-nucleares). The fibers of the ambiguous nucleus, together with other motor fibers of the vagus nerve, participate in the innervation of the muscles of the pharynx, larynx, esophagus, etc. (see Vagus nerve).