Anatomy of Tongue

basic anatomy of tongue,muscles of tongue,nerve and blood supply of tongue and clinical features

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2. Presented by ; Humayun Afridi Saqib Habib Taif Ahmad Faisal Mansoor. Khyber College of Dentistry Peshawar

3. Contents Introduction General Features Papillae , Types Taste Buds Extrinsic & Intrinsic Muscles Movements Vasculature Innervation Functions Clinical Aspects

4. INTRODUCTION & GENERALFEATURES SAQIB HABIB CLASS NO: 40

5. INTRODUCTION Mass of striated muscles covered with mucous membrane Voluntary muscular structure Length : 3 inches Location : floor of the mouth Shape : triangular Attachement : With mandible and hyoid bone Has an apex , body and root

6. GENERAL FEATURES SURFACES : Two surfaces Superior surface Inferior surface Superior surface is divided into three parts Anterior 2/3 part called as Oral part Posterior 1/3 part called as Pharyngeal part Base(root) of tongue

7. General Features TERMINAL SULCUS V- shaped sulcus divides tongue into anterior & posterior parts Apex of sulcus marked by a pit - FORAMEN CECUM

8. General Features Foramen cecum ,an embryological remnant, marks the upper end of thyroglossal duct Sometime a thyroglossal duct persists and connects the foramen cecum with the thyroid gland in neck( thyroglossal cyst)

9. Superior Surface Oral Part(anterior 2/3): Comprises of a median furrow Rough surface due to presence of papillae Surrounded by anterior and lateral teeth Mobile part of tongue

10. Superior Surface Pharyngeal Part(Posterior 1/3) Lies behind the sulcus terminalis No papillae, shows nodular surface, presence of lymphatic nodules and lingual tonsils Contributes to the anterior wall of oropharynx

11. Pharnygeal Part

12. Base of Tongue Base of tongue is far back and is bottom of tongue Contributes to the front wall of pharynx Movement can affect the diameter of pharynx i.e When it push forwards, thereby expanding the pharynx When it pull backwards, thereby constricting the pharynx Lacks papillae

13. INFERIOR SURFACE Covered by smooth mucous membrane In the midline , a mucosal fold called Frenulum connects the tongue with the floor of the mouth Lateral to frenulum, deep lingual vein can be seen through the mucosa Lateral to the lingual vein , mucosal fold called as plica fimbriata is present

14. Frenulum Lingual veins Plica fimbriata

15. PAPILLAE

16. PAPPILAE Indentation of any structure in the overlying epithelium is called papillae Superior surface of tongue , covered by numerous papillae Have taste buds on their surfaces Types of of papillae; Vallate/circumvallate Filiform Fungiform Foliate

17. Vallate Papillae Largest among papillae SHAPE : Blunt-ended cylindrical NUMBER : 8 to 12 LOCATION : infront of sulcus terminalis ARRANGEMENT : Occur in V shape line

18. VALLATE PAPILLAE

19. Filiform Papillae SHAPE : Thin, long papillae having pointed ends ‘V’ shaped cones Only papillae having no taste buds NUMBER : numerous These papillae are mechanical and not involved in gustation Identified by increased keratinization LOCATION : Present at pre-sulcal area of the tongue

20. L HISTOLOGICAL VEIW

21. Fungiform Pappilae SHAPE: slightly mushroom-shaped if looked at in longitudinal section Taste buds on their surfaces LOCATION: apex of the tongue as well as the margins Larger than filiform papillae

22. FUNGIFORM PAPILLAE

23. Foliate Pappilae SHAPE : Short vertical folds LOCATION : Present lateral to terminal sulcus and at margins

24. FOLLIATE PAPILLAE

25. Taste Buds Sensory receptors for taste The sensation of taste is called gustation Taste buds are located on the surfaces of papillae except filiform papillae

26. Electron microscopic structure of taste buds

27. Taste Buds Four taste sensations, recently a fifth basic taste has been added: sour, sweet, salty, bitter and the recently added umami UMAMI

28. Umami Taste Umami is from japanese word which means ‘ pleasant savory taste’ Human tongue has glutamate receptors, which is the source of umami flavour Kikunae ikeda, japanese scientist proposed its existence in 1908 This taste is mostly found in fish, cured meats, mushrooms, cheese, spinach etc.

29. Interesting Facts Women have shorter tongue than men. Blue whale has the largest tongue in animal kingdom and weighs 5400 lbs About half of all bacteria in your mouth live on your tongue Tongue heals faster than any part of the body Your tongue is germ free only if it is pink. If it is white there is a thin film of bacteria on it.

30. Chinese believe that tongue is representative of organs of body

31. Muscles of Tongue BY TAIF AHMAD Class No; 74

32. MUSCLES OF THE TONGUE

33. The tongue is divided into two halves by a median septum and the muscles of each half consist of Intrinsic And Extrinsic Muscles Therefore each muscle occur in Pair.

34. INTRINSIC MUSCLES These muscles are confined to the tongue, They originate and inserts within the tongue, No bony attachments, FUNCTION : They alter the shape of tongue

35. Types of Intrinsic Muscles There are four types Superior Longitudinal, Inferior Longitudinal, Vertical muscles, And Transverse muscles.

36. Superior Longitudinal Muscle It lies just beneath the dorsum of the tongue. ACTION: It curls the tip upward and rolls it posteriorly

37. Superior longitudinal

38. Action of Superior Longitudinal Muscle

39. Inferior Longitudinal Muscles Lies on each side lateral to the Genioglossus muscles, ACTION: They curl the tip of tongue inferiorly.

40. Inferior longitudinal

41. Transverse Muscles Lies inferior to the superior longitudinal muscle and run from the septum to margins ACTION: They narrow the tongue and increase its height.

42. Vertical muscles It runs inferolaterally from the dorsum, ACTION: Flattens the dorsum.

43. Vertical and transversE

44. EXTRINSIC MUSCLES These muscles take origin from parts outside the tongue, therefore move the tongue as well as alter the shape. Divided into four types namely; ) GENIOGLOSSUS ) HYOGLOSSUS ) STYLOGLOSSUS ) PALATOGLOSSUS

45. STYLOGLOSSUS and PALATOGLOSSUS attach the tongue superiorly, while GENIOGLOSSUS and HYOGLOSSUS attach the tongue inferiorly.

46. GENIOGLOSSUS ORIGIN : From superior mental spines, INSERTION : Into the mucous membrane of the tongue. Action : Protrudes the tongue, depress central part of tongue and increase the volume of mouth as in sucking. GENIOGLOSSUS

47. HYOGLOSSUS ORIGIN : Arises from greater horn and body of hyoid bone, INSERTION : Side of tongue. ACTION : It depresses side of tongue assisting GENIOGLOSSUS to enlarge oral cavity. HYOGLOSSUS

48. STYLOGLOSSUS ORIGIN : Lower part of Styloid process and upper part of stylohyoid ligament, INSERTION : Side of tongue . ACTION : Elevates and retracts the tongue. STYLOGLOSSUS

49. PALATOGLOSSUS ORIGIN : From soft palate. INSERTION : Lateral margin of tongue. ACTION: Elevates back of tongue and depresses soft palate.

50. Movements Protrusion: Genioglossus on both sides acting together Retraction: Styloglossus and hyoglossus on both sides acting together Depression: Hyoglossus and genioglossus on both sides acting together Elevation: Styloglossus and palatoglossus on both sides acting together

51. INNERVATION Both extrinsic and intrinsic muscles are supplied by HYPOGLOSSAL NERVE except PALATOGLOSSUS muscle which is in turn supplied by VAGUS NERVE .

52. FACTS 1). The tongue is the strongest muscle in the body and the only muscle that is connected only at one end . 2). Using a tongue scraper to clean your tongue is proven to prevent heart attacks, pneumonia , premature births, diabetes. 3). Your tongue never stops working. Even when you sleep it is pushing saliva into your throat.

53. VASCULATURE & INNERVATION OF TONGUE HUMAYUN AFRIDI CLASS No. 55

54. BLOOD SUPPLY Arterial Supply Lingual artery - supplies tongue and floor of the mouth. Originates from external carotid artery in neck Passes between hyoglossus and genioglossus muscles of tongue I Lingual artery

55. Arterial Supply Lingual artery mainly gives three branches within the tongue namely Dorsal lingual artery Deep lingual artery Sub lingual artery

56. Arterial Supply Also secondary supply to the tongue by: Tonsillar branch of facial artery Ascending pharyngeal artery (branch of external carotid artery)

57. Venous Drainage Drained by dorsal lingual vein and deep lingual veins Deep Lingual Veins: Begins near tip of tongue and run beneath the mucous membrane Visible on the inferior surface of tongue Anterior to lingual artery Ultimately drains into internal jugular vein Deep lingual vein Dorsal lingual vein

58. Deep lingual vein

59. Venous Drainage Dorsal Lingual Veins Drain the dorsum and sides of tongue Runs along the lingual artery Drains into internal jugular vein Dorsal lingual vein

60. Lymphatics Apical Vessels: Drains into Submental nodes & deep cervical nodes Marginal Vessels: Drains into Submandibular nodes & deep cervical nodes Basal Vessels: Drains into Deep cervical nodes (jugulodigastric mainly)

61. LYMPH VESSELS AFFERENT(RECEIVING) EFFERENT(DRAINING) 1. APICAL i . TIP ii. FRENULUM - SUBMENTAL ( MAJOR LYMPH NODE ) 2. MARGINAL SIDE OF TONGUE IN FRONT OF SULCUS TERMINALIS - SUBMANDIBULAR NODE - JUGULODIGASTRIC JUGULO- DIGASTRIC (deep cervical nodes) 3. BASAL POSTERIOR 1/3 RD or Base Lymphatic drainage

62. Innervation Innervation is complex and consists of three different supplies Motor supply General sensory supply Special sensory supply

63. Motor Supply All extrinsic and intrinsic muscles are supplied by HYPOGLOSSAL NERVE except PALATOGLOSSUS muscle which is supplied by VAGUS NERVE.

64. Sensory supply General sensory sensation is by three nerves Lingual nerve – anterior 2/3 rd of tongue Glossopharyngeal nerve – posterior 1/3 rd of tongue Vagus nerve – posterior most part of tongue

65. Special sensory supply Supplied by three nerves Chorda tympani (facial) – taste sensation of anterior 2/3 rd of tongue Glossopharyngeal ( ix) – taste sensation of posterior 1/3rd of tongue Vagus nerve ( x ) – taste sensation of posterior most part

66. Functions Deglutition Taste sensation Speech production Breast feeding Self cleansing system Mastication

67. G LOSSITIS is usually a part of generalized ulceration of mouth cavity . In certain anaemias due to atrophy of filiform papillae tongue becomes smooth. The presence of a rich network of lymphatics and loose areolar tissue in the substance of tongue is responsible for the enormous swelling of the tongue in acute glossitis . Clinical aspects

68. The under-surface of the tongue is good site for observation of jaundice . In unconscious patients , the tongue may fall back and obstruct the air passage. This can be prevented either by lying the patient on one side with head down or by keeping the tongue out mechanically. Referred pain is felt in the ear in diseases of posterior part of tongue, as ninth nerve commonly supply to both the regions Clinical aspects

69. Carcinoma of tongue is quite common. The affected side is removed surgically. Carcinoma of posterior one third is more dangerous. Clinical aspects

70. Now, Lets find how attentive were you…

71. MCQS

72. Q1) WHICH PAPILLAE ARE RIGHT ANTERIOR TO SULCUS TERMINALIS? Foliate Vallate Fungiform Filiform

73. Q2) WHICH OF THE ONLY MUSCLES OF THE TONGUE IS INNERVATED BY THE VAGUS NERVE[X]? Styloglossus Genioglossus Palatoglossus Hyoglossus

74. Q3) DEEP LINGUAL VEINS DRAIN INTO: External Jugular Vein Internal Jugular Vein

75. Q4) CHORDA TYMPANI IS BRANCH OF WHICH CRANIAL NERVE? Vestibulocochlear Facial Glossopharyngeal Hypoglossal

76. Q5) CHORDA TYMPANI IS THE NERVE OF TASTE FOR ALL EXCEPT WHICH PAPILLAE? Filiform Fungiform Foliate Vallate

77. Q6) WHICH OF THE PAPILLAE ARE NUMEROUS OF ALL IN NUMBER? Filliform Fungiform Foliate Vallate

78. Think About This “ In Medical School we have a hundred classes that teach us how to fight off death…And not one lesson on how to go on living.”