Tongue is protrude by
(Genioglossus) (252-BDC-3- 4th edition)Action of Extrinsic muscle of TongueGENIOGLOSSUSDraws the tongue forward and protrude the tip so that it points to the opposite side. The two muscle acting in union protrude the tongue in the midlineHYOGLOSSUSIt depresses the tongue** makes the dorsum convex and helps in retracting the protruded tongueSTYLOGLOSSUSDuring swallowing it pulls the tongue upwards and backwardsPALATOGLOSSUSPulls up root of the tongue and approximates the palatoglossal arches and thus closes oropharyngeal isthmus* Safety muscle of tongue is - Genioglossus* Ipsilateral deviation of tongue is due to unaltered action of - Genioglssus* Palsy of right genioglossus causes- devition of tongue to right**** All the intrinsic and extrinsic muscles EXCEPT THE PALATOGLOSSUS** are supplied by cranial part of accessory nerve through the pharyngeal plexusImportant Points1. Tip of the tongue drain into submental lymph nodes*2. Anterior 2/3 of the tongue drain into submandibular lymph node and posterior 1/3 of the tongue drain into Jugulo omohyoid (Lymph node of the tongue)3. Anterior 2/3 of tongue developed from first branchial arch*. Therefore it is supplied by lingual nerve** and chorda tympani4. Posterior 1/3 of tongue develops third branchial arch** therefore it is supplied by glossopharyngeal nerve**5. Posterior most part from the fourth arch: therefore supplied by the Vagus nerve6. Circumvallate papillae are innervated by Glossopharyngeal nerve**7. Circumvallate papillae- are situated on the mucous membrane just anterior to the sulcus terminalis an therefore their taste buds are innervated by ninth cranial nerve***8. Unilateral injury to hypoglossal nerve leads to(I) Hemiatrophy of involved side *(II) Deviation of tongue towards the same side *(III) Fasciculation of tongue *9. Intrinsic muscles of the tongue are derived from occipital somites
Hyoglossus
Palatoglossus
Genioglossus
Styloglossus
Head & Neck