tongue.pdf

TONGUE Tongue is a muscular organ located on the floor of the oral cavity. Speaking , chewing , swallowing are the functions of tongue. EXTERNAL FEATURES Tounge has three parts ❖ Root ❖ Body ❖ Tip Root is the attached part It attac...

TONGUE Tongue is a muscular organ located on the floor of the oral cavity. Speaking , chewing , swallowing are the functions of tongue. EXTERNAL FEATURES Tounge has three parts ❖ Root ❖ Body ❖ Tip Root is the attached part It attaches with the mandible, hyoid bone, palate and styloid bone Tip Is the free part behind the incisors Body It has two surfaces 1) Upper surface and inferior surface 2) Upper surface is called dorsum Dorsum has two parts divided by V shaped sulcus terminalis Oral part (anterior part) Pharyngeal part (posterior part) There is a foramen at the apex of the sulcus terminalis called foramen caecum. Palatopharyngeal arch extending from the palate to limb of the sulcus terminalis is present at the lateral part of oral cavity There is tree different type of papillae presents on the tongue 1. Fungiform 2. Filiform 3. Circumvallate On the lateral margin of the tongue 4 to 5 vertical foldings are present known as the foliate papillae. Inferior surface Inferior surface has mucus layer on it  It attaches with the floor of the mouth by a fold of membrane called frenulum linguae. On the either side of the frenulum there is deep lingual vein. Lateral to the vein there is a fold of membrane called plica fimbriata. Pharyngeal part The part of the tongue is behind the sulcus terminalis is called pharyngeal part. It has no papillae on it It has lot of lymph nodes on it called lingual tonsil Posterior most part It attaches with the epiglottis via three folds Median glossoepiglottic fold And right and left lateral glossoepiglottic fold Space between lateral and medial glossoepiglottic fold is called vallecula. Papillae of the tongue Circumvallate papillae They are 8 to 12 in number Found anterior to the sulcus terminalis It is cylindrical in shape and has a circular fold around it Fungiform papillae They are numerous  Found at the tip and margin of the tongue It has a narrow pedicle and rounded head It is bright red in colour Filiform papillae Found at the dorsum of the tongue It gives velvet appearance to the tongue It is conical in shape Muscle of the tongue There are four intrinsic muscles Superior longitudinal – helps to shortens the tongue Inferior longitudinal – shortens the tongue Vertical – make the tongue broad and flat. Transverse - helps to elongate the tongue Four extrinsic muscles Muscle Origin Insertion Action Nerve supply Genioglossus Genial tubercle of entire length of Protrusion and Hypoglossal mandible the tongue. depression of the tongue. Hyoglossus hyoid bone the lateral aspect Retraction and Hypoglossal of the tongue. elevation of the tongue.  Styloglossus Styloid process lateral aspect of Retraction and Hypoglossal the tongue. elevation of the tongue. Palatoglossus Palate palatine broadly along the Spinal aponeurosis tongue. accessory Arterial supply Lingual artery – branch of external carotid artery. Venous drainage Deep lingual vein drains into internal jugular vein Nerve supply Motor supply All the muscles except palatoglossus is supplied by HYPOGLOSSAL NERVE Palatoglossus supplied by SPINAL ACCESSORY NERVE Sensory supply Anterior two-third - General sensation - lingual nerve Special sensation – chorda tympani Posterior one-third General sensation and taste sensation – glossopharyngeal nerve Posterior most part Vagus nerve Clinical anatomy Megaloglossia – presence of a tongue of unusual size Microglossia – presence of very small tongue Aglossia – it is a condition of absence of tongue