Which of the suprahyoid muscle is supplied by both facial nerve and mandibular nerve -
Ans, is 'c' i.e., Digastric o Anterior belly of digastric is supplied by nerve to myelohyoid (a branch of mandibular nerve) and posterior belly is supplied by facial nerve. Suprahyoid musclesMuscle1. Digastric (DG)has two belliesOrigin(a) Anterior belly (DGA) from digastric fossa of mandible(b) Posterior belly (DGP) from mastoid notch of temporal boneFibres(a) Anterior belly runs downwards and backwards(b) Posterior belly runs downwards and forwardsInsertionBoth heads meet at the intermediate tendon which perforates SH and is held by a fibrous pulley to the hyoid boneNerve supplyAnterior belly by nerve to mylohyoidFacial nerveActions(a) Depresses mandible when mouth is opened widely or against resistance; it is secondary to lateral pterygoid(b) Elevates hyoid bone2.Stylohyoid (SH).Posterior surface of styloid processTendon is perforated by DGP tendonJunction of body and greater cornua of hyoid boneFacial nerve(a) Pul Is hyoid bone upwards and backwards(b) with other hyoid muscles, it fixes the hyoid bone3.Mylohyoid (MH) Flat triangular muscle; two mylohoids form floor of mouth cavity.Mylohyoid line of mandibleFibers run medially and slightly downwards(a) Posterior fibers; body of hyoid bone(b) Middle and anterior fibers; median raphe, between mandible and hyoid boneNerve to mylohyoid(a) Elevates floor of mouth in first stage of deglutition(b) Helps in depression of mandible, and elevation of hyoid bone4. Gemohyoid (GH).Inferior mental spine (genial tubercle)Runs backwrds and downwardsAnterior surface of body of hyoid boneCl through hypoglossal nerve(a) Elevates hyoid bone(b) May depress mandible when hyoid is fixed5. Hyoglossus. It is a muscle of tongue.Whole length of greater cornua and lateral part of body of hyoid boneFibers run upwards and forwardsSide of tongue between styloglossus and inferior longitudinal muscle of tongueHypoglossal (XII) nerveDepresses tongue makes dorsum convex retracts the protruded tongue
Stylohyoid
Mylohyoid
Digastric
Hyuglossus
Triangles of Neck