Gross-Anatomy and Histology

1. Gross- Anatomy & Histology of
Tongue
Dr. Rabia Inam Gandapore
Assistant Professor
Head of Department Anatomy
(Dentistry-BKCD)
B.D.S (SBDC), M.Phil. Anatomy (KMU),
Dip. Implant (Sharjah, Bangkok, ACHERS) , CHPE
(KMU),CHR (KMU), Dip. Arts (Florence, Italy)

2. Teaching Methodology
 LGF (Long Group Format)
 SGF (Short Group Format)
 LGD (Long Group Discussion, Interactive discussion with the use of models or diagrams)
 SGD (Short Group)
 SDL (Self-Directed Learning)
 DSL (Directed-Self Learning)
 PBL (Problem- Based Learning)
 Online Teaching Method
 Role Play
 Demonstrations
 Laboratory
 Museum
 Library (Computed Assisted Learning or E-Learning)
 Assignments
 Video tutorial method

3. Goal/Aim (main objective)
To help/facilitate/augment the students about the:
 Describe external features of tongue.
 Describe muscles of tongue, their origin and insertion, actions.
 Explain lymphatic drainage, blood and nerve supply of tongue.
 Enumerate relevant clinical problems tongue (glossitis, lingual tonsil,
carcinoma etc.).
 Describe histological features of tongue.
 Describe histological features of taste buds.

4. Specific Learning Objectives (cognitive)
At the end of the lecture the student will able to:
 Recognize the gross anatomical features of the external features of tongue.
 Describe muscles of tongue, their origin and insertion, actions.
 Explain lymphatic drainage, blood and nerve supply of tongue.
 Enumerate relevant clinical problems tongue (glossitis, lingual tonsil,
carcinoma etc.).
 Describe histological features of tongue.
 Describe histological features of taste buds.
 Sketch labeled diagram of the tongue histology

5. Psychomotor Objective: (Guided response)
 A student to draw labelled diagram of the tongue histology

6. Affective domain
 To be able to display a good code of conduct and moral values in the class.
 To cooperate with the teacher and in groups with the colleagues.
 To demonstrate a responsible behavior in the class and be punctual, regular, attentive and
on time in the class.
 To be able to perform well in the class under the guidance and supervision of the teacher.
 Study the topic before entering the class.
 Discuss among colleagues the topic under discussion in SGDs.
 Participate in group activities and museum classes and follow the rules.
 Volunteer to participate in psychomotor activities.
 Listen to the teacher's instructions carefully and follow the guidelines.
 Ask questions in the class by raising hand and avoid creating a disturbance.
 To be able to submit all assignments on time and get your sketch logbooks checked.

7. Lesson contents
Clinical chair side question: Students will be asked if they know what is the function
of
Outline:
 Activity 1 The facilitator will explain the student's Tongue Gross anatomy &
Histology
 Activity 2 The facilitator will ask the students to make a labeled diagram of the
histology of tongue
 Activity 3 The facilitator will ask the students a few Multiple Choice Questions
related to it with flashcards.

8. Recommendations
 Students assessment: MCQs, Flashcards, Diagrams labeling.
 Learning resources: Langman’s T.W. Sadler, Laiq Hussain Siddiqui, Snell
Clinical Anatomy, Netter’s Atlas, BD Chaurasia’s Human anatomy, Internet
sources links.

9. Gross Anatomy of Tongue
 EXTERNAL FEATURES OF TONGUE.
 MUSCLES OF TONGUE, THEIR ORIGIN, INSERTION & ACTIONS.
 LYMPHATIC DRAINAGE, BLOOD & NERVE SUPPLY OF TONGUE.
 ENUMERATE RELEVANT CLINICAL PROBLEMS TONGUE (GLOSSITIS, LINGUAL TONSIL, CARCINOMA ETC.).

10. Tongue
 Mass of striated muscle covered with
mucous membrane.
 Anterior 2/3rd: Lies in mouth
 Posterior 1/3rd: Lies in pharynx
 The muscles attach the tongue to:
Above: styloid process & soft palate
Below: mandible & hyoid bone.
 Its divided into right & left halves by
median fibrous septum.

13. Mucous Membrane of Tongue
A. Mucous Membrane of Upper Surface of Tongue is divided by a V-shaped sulcus, the
sulcus terminalis into:
 Anterior part
 Posterior part
 Apex of sulcus projects backward & is marked by a small pit, the foramen cecum
which is embryologic remnant & marks the site of upper end of thyroglossal duct.
 Sulcus serves to divide the tongue into:
a. Anterior 2/3rd (Oral part): 3 types of papillae are present on upper surface
1. Filiform papillae
2. Fungiform papillae
3. Vallate papillae.
b. Posterior 1/3rd (Pharyngeal part): devoid of papillae but has an irregular surface,
caused by presence of underlying lymph nodules, the lingual tonsil.

16. B. mucous membrane on inferior surface of
tongue is reflected from tongue to floor of the
mouth.
 In midline anteriorly, undersurface of tongue is
connected to floor of the mouth by a fold of
mucous membrane, the frenulum of tongue.
 On lateral side of frenulum, the deep lingual
vein can be seen through mucous membrane.
 Lateral to lingual vein, the mucous membrane
forms a fringed fold called the plica fimbriata

18. Muscles of the Tongue

19. Muscles of the Tongue
 Divided into two types:
A. Intrinsic Muscles
 Confined to tongue & are not
attached to bone.
 Consist of:
 Longitudinal Fibers
 Transverse Fibers
 Vertical Fibers
Nerve supply: Hypoglossal nerve
Action: Alters shape of tongue
B. Extrinsic Muscles
 Attached to bones & soft
palate.
 They are:
 Genioglossus
 Hyoglossus
 Styloglossus
 Palatoglossus.
Nerve supply: Hypoglossal nerve
Action: Depresses tongue, Draws
tongue upward and backward, Pulls
roots of tongue upward & backward,
Narrows oropharyngeal isthmus

20. Intrinsic Muscles

21. Extrinsic Muscles

22. Muscle Origin Insertion Nerve Supply Action
Intrinsic Muscles
Longitudinal
Median septum &
submucosa
Mucous membrane
Hypoglossal
nerve
Alters shape of
tongue
Transverse Vertical
Extrinsic Muscles
Genioglossus
Superior genial spine of
mandible
Blends with other
muscles of tongue
Hypoglossal
nerve
Protrudes apex
of tongue
through mouth
Hyoglossus
Body and greater cornu
of hyoid bone
Depresses
tongue
Styloglossus
Styloid process of
temporal bone
Draws tongue
upward and
backward
Palatoglossus Palatine aponeurosis Side of tongue Vagus Nerve
Pulls roots of
tongue upward
and backward,
narrows
oropharyngeal
isthmus

24. Movements of the Tongue
 Protrusion: Genioglossus muscles on both
sides acting together
 Retraction: Styloglossus & hyoglossus muscles
on both sides acting together
 Depression: Hyoglossus muscles on both sides
acting together
 Retraction and elevation of posterior third:
Styloglossus & Palatoglossus muscles on both
sides acting together
 Shape changes: Intrinsic muscles

25. Blood, Vein, Nerve & Lymphatic Supply
 Blood Supply
1. Lingual artery
2. Tonsillar branch of facial artery
3. Ascending pharyngeal artery
 Veins drain into internal jugular vein.
 Lymph Drainage
Tip: Submental lymph nodes
Sides of the anterior 2/3rd : Submandibular & deep cervical lymph nodes
Posterior 1/3rd : Deep cervical lymph nodes

28. Sensory Innervation
 Anterior 2/3rd :
General sensation: Lingual nerve
branch of mandibular division of
trigeminal nerve
Special Sensation (TASTE): Chorda
tympani branch of facial nerve (taste)
Excludes vallate papillae
 Posterior 1/3rd :
General sensation & taste:
Glossopharyngeal nerve
Includes vallate papillae

30. Mucous Membrane
covering Anterior
2/3rd of Tongue
Mucous Membrane
covering Poterior
1/3rd of Tongue
Posterior Most Part
of Tongue Root
Taste Sensation
(Sensory)
Chorda Tympani
(branch of facial
nerve) Excludes
vallate papillae
Glossopharyngeal
nerve (IX)
Includes vallate
papillae
Vagus nerve (via
Internal Laryngeal
branch)
General Sensation
(Sensory)
Lingual nerve
(Mandibular nerve
V3)
Glossopharyngeal
nerve
Internal Laryngeal
nerve (X) branch of
vagus
Intrinsic Muscles
(Motor)
All supplied by Hypoglossal Nerve (XII)
Extrinsic Muscles
(Motor)
All supplied by Hypoglossal nerve except Palato-glossus
muscle= Supplied by Pharyngeal Plexus (X,XI), cranial root of
accessory nerve

31. Clinical Correlation

32. Clinical Correlation
Laceration of the Tongue
 caused by patient’s teeth following a blow on chin
 Accidental bites tongue while eating
 During recovery from an aesthetic,
 During an epileptic attack.
 Bleeding is halted by grasping tongue between
the finger & thumb posterior to laceration,
occluding branches of lingual artery.

33. Lingual Tonsils- Tonsillitis

34. Fissured Tongue

35. Canker Sore Tongue

36. Taste Concerns

37. Lymphangioma

38. Glossitis
 Inflammation of tongue (Red, smooth, sore tongue)
 Maybe
a. Primary:
 Bacterial or Viral Infections
 Mechanical imitation from tooth, dentures ect
 Tobacco, Hot food & Alcohol
 Allergy to toothpaste, mouthwash etc
a. Secondary
 Benign or Malignant

39. Hairy appearance of tongue

40. Ankyloglossia

41. Beckwith–Wiedemann syndrome

42. Oral cancer

43. Papilloma

44. Burning tongue

45. Angioedema

46. Thrush

47. Leukoplakia

48. Neuralgia
 Blood vessels pressing
on the glossopharyngeal
nerve.
 Growths at the base of
the skull pressing on the
glossopharyngeal nerve.
 Tumors or infections of
the throat and mouth
pressing on the
glossopharyngeal nerve

49. Trauma

50. Streptococcal pharyngitis

51. Vitamin deficiency
 vitamin B-12.
 iron.
 folate.
 zinc

52. Discoloration

53. Smoking
 Smoker's Melanosis
 Periodontal Disease
 Nicotinic Stomatitis
 Smokeless Tobacco Induced Changes
 Gingival Recession & Tooth Abrasion
 Black Hairy Tongue
 Oral Cancer

54. Anemia

55. Histology of Tongue
HISTOLOGICAL FEATURES OF:
 TONGUE.
 TASTE BUDS.

56. Tongue
 Mass of skeletal muscle
covered by mucous
membrane & fibers cross
eachother in 3 directions:
1. Longitudinal
2. Transverse
3. Vertical

58.  Mucous membrane adherent to muscle consists of:
1. Epithelium: Stratified Squamous being
a. Ventral (Lower): Surface: Non-Keratinized
b. Dorsal (upper): Keratinized, it is rough & irregular &
divided by sulcus terminalis into:
 Anterior 2/3rd
 Posterior 1/3rd : appears to be irregular nodular
because the root of tongue lodge aggregations of
lymphatic nodules which constitute Lingual tonsils;
Epithelium crypts are associated with these
aggregations
2. Lamina Propria

61. Lingual Papillae
1. FILIFORM PAPILLAE
2. FUNGIFORM PAPILLAE
3. CIRCUMVALLATE PAPILLAE
4. FOLIATE PAPILLAE

62. Lingual Papillae
 Anterior 2/3rd on dorsal surface of
tongue are rough due to lingual
papillae
 These papillae formed of central core of
connective tissue & covering layer of
stratified squamous epithelium
 Classified into 4 types
1. Filiform Papillae
2. Fungiform Papillae
3. Circumvillate Papillae
4. Foliate Papillae

63. 1. Filiform Papillae
 Thread-Like/ Slender-form called
filliform
 Donot have taste buds
 Most numerous and smallest
 Distributed over entire dorsal surface of
tongue body ( anterior 2/3rd)
 Covered by stratified squamous
keratinized epithelium that tapers to a
point which is directed backwards.

67. 2. Fungiform Papillae
 Scattered among filiform papillae
 Abundant close to tip of tongue
 Mushroom shape with narrow stalk &
dilated upper part
 Covered by stratified squamous non-
keratinized epithelium
 Taste buds located on dorsal surface

68. 3. Circumvallate Papillae (Vallate)
 Large domed shaped structures present in lingual mucosa just anterior & parallel to sulcus
terminalis
 8-12 present in human tongue
 They sunk into lingual mucosa & is surrounded by a deep trench like groove lined by Stratified
Squamous Non-Keratinized Epithelium. The papillae are covered by same type of
epithelium
 Numerous taste buds located in epithelial lining of groove & on sides (not on dorsum) of
circumvallate papillae.
 Ducts of Von Ebner’s Glands (Lingual Salivary glands of serous variety) open into base of
grooves surrounding these papillae
 The watery secretion of these galnds serves to flush food materials out of groove surrounding
the circumvallate papillae, so that taste buds can respond to the rapidly changing taste
stimuli

72. 4. Foliate Papillae
 Minimally developed in humans
 Occurs on sides of tongue as
parallel low ridges separated by deep
mucosal furrows
 Easily identifiable on tongue of
young children but undergo gradual
atrophy and in aged person
unrecognizable

73. Glands of Tongue
1. ANTERIOR LINGUAL GLANDS
2. GLANDS OF VON EBNER
3. MUCOUS GLANDS OF THE ROOT

74. Glands of Tongue
 3 main groups of simple tubular (Tubulo-acinar glands) occur in
tongue:
1. Anterior Lingual Gland: Constitute paired group of mixed
(Seromucous) glands located under tip of tongue. Embedded in
muscle & their ducts opens on ventral surface of tongue
2. Gland of Von Ebner: Group of purely serous glands located in the
region of circumvallate papillae. They extend into muscle & their ducts
open into grooves surrounding the circumvallate papillae. Watery
secretions of these glands washes away food particles these grooves ,
allowing reception of new gustatory stimuli by the taste buds of
Circumvallate papillae.
3. Mucous Glands of the Root: Numerous small purely mucous
glands lie in posterior 1/3rd of tongue. Their ducts opens in crypts of
lingual tonsils

77. Taste Buds

78. Taste Buds
 Receptors of taste sensations
1. Located on dorsal surface of body of tongue
2. Soft palate
3. Laryngeal surface of epiglottis
 Lingual Taste buds: are embedded within stratified squamous epithelium
covering the fungiform & circumvallate papillae & rest on basal lamina of
epithelium.
 H&E stain: Taste bud appears as:
Oval
Pale staining body 70-80 micro m long & 40-50 m wide
 Taste bud extends through full thickness of epithelium covering the papillae
 Stained sections: taste buds appears distinctly paler than epithelium. The
apex of each taste bud communicates with the oral cavity through a small
aperture called Taste Pore.

83.  Taste bud is composed of 50-90 cells
classified into following 3 types:
1. Sustentacular Cells (Supporting cells)
2. Neuroepithelial cells (Taste Cells)
3. Basal Cells

85. 1. Sustentacular cells
 Supporting cells
 Elongated cells extends from basal lamina
to taste pore
 Apical end : these cells bear long
microvilli that project into taste pore
 2 Varieties
1. Dark Cells: Type -I
2. Light Cells: Type-II

86. 2. Neuroepithelial cells / Taste cells
 Taste cells or Type-III cells
 Gustatory receptor cells
 Elongated, Tall columnar cells extends from
basal lamina to taste pore & bear long
microvilli that project into taste pore
 Base: taste cells form synapses with
afferent nerve fibers through which taste
sensation is conveyed to CNS
 Apical End: Neuroepithelial &
sustentacular are joined to each other &
surrounding epithelial cells by tight junctions

87. 3. Basal cells
 Small cells
 Located close to basal lamina
 Serve as stem cells for other cells of taste
buds
 Divide & Differentiate into Sustentacular &
Taste cells to regenerate these cells
 Average life span 10days.

89. Thank You