The cervical plexus also communicates with the cranial nerves vagus nerve and hypoglossal nerve. Associated cranial nerves are the oculomotor, abducens, trochlear, and hypoglossal nerves. Waller experimented on frogs in 1850, by severing their glossopharyngeal and hypoglossal nerves. The hypoglossal nucleus is derived from the basal plate of the embryonic medulla oblongata. V (trigeminal), VII (facial) and XII (hypoglossal). The hypoglossal nerve traverses the canal. Emerging from the anterolateral sulci are the CN XII (hypoglossal nerve) rootlets. There is anastomosis with accessory nerve, hypoglossal nerve and sympathetic trunk. The hypoglossal nerve is of a general somatic efferent (GSE) type. The vocal tract is supplied by the hypoglossal nerve and facial nerves. The hypoglossal nerve (XII) supplies the intrinsic muscles of the tongue, controlling tongue movement. Motor neuron disease is the most common disease affecting the hypoglossal nerve. Lies at the anterolateral margins of the f. magnum and transmits the hypoglossal (XII) nerve. Geniohyoid&colon; by a branch from the hypoglossal nerve consisting of fibres from the C1 nerve. It lies superior to lingual and hypoglossal nerves.