In lesion of the right hypoglossal nucleus, the tip of the tonge on protrusion turns to:
Lesion of hypoglossal nucleus: Lesion of the hypoglossal nucleus, there is ATROPHY of the muscles of the IPSILATERAL one-half of the tongue. This is a lower motor neuron lesion. Upon closer examination, FASCICULATIONS (tiny, spontaneous contractions) can be seen. Both fasciculations and atrophy result from the loss of the normal innervation of the muscle by the lower motor neurons in the hypoglossal nucleus. Upon protrusion, the tongue will dete TOWARD the side of the lesion (i.e., same side). This is due to the unopposed action of the genioglossus muscle on the normally innervated side of the tongue (the genioglossus pulls the tongue forward). Ref: Snells Clinical anatomy, 6th Edition, Page 736, 737.
Left side because of paralysis of left side tongue mscles
Right side because of paralysis of right side tongue mscles
Right side because of the unopposed action of left geniglossus muscle
Left side because of the unopposed action of left geniglossus muscle