Gustatory System

MusclesIntrinsic : The longitudinal, transverse and vertical musclesExtrinsic : The genioglossus, hyoglossus, styloglossus and palatoglossus muscles

Mucous membraneSulcus terminalis v-shaped groove, upper surface of the tongueType of papillae: Papilla filiformis Papilla fungiformis Papilla vallatae 10-12 in number

Blood SupplyArteri lingualis Ramus tonsilaris a. FacialisA. Pharyngea ascendens

Clinical NotesLaceration of The Tongue : Bleeding is halted by grasping the tongue between the finger and thumb posterior to the laceration, thus occluding the branches of the lingual artery.

Lymph drainageTip : submental lymph nodesSides of anterior two thirds : submandibular lymph nodesPosterior third : deep cervical lymph nodes

Sensory and Motoric InnervationAnterior two thirds : the lingual nerve (general sensation) and chorda tympani (taste)Posterior two thirds : the glossopharyngeal nerve (general sensation and taste)Motoric : n.hypoglossus

Chorda tympani

Movement of the tongueProtrusion: m.genioglossus (both sides)Retraction : m.styloglossus and m.hyoglossus (both sides)Depression : m.hyoglossus (both sides)Retraction and elevation of posterior third m.styloglossus and m. Palatoglossus (both sides)Shape changes: intrinsic muscles

Gustatory Pathway

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