tongue

1. Presented by
Dr. Athulya Lakshmanan
Department of Prosthodontics
TONGUE

2. Contents
Introduction
Development of tongue
Anatomy of tongue
 Parts and surfaces of the tongue
 Muscles of the tongue
 Vascular supply of the tongue
 Lymphatic drainage of the tongue
 Innervation of the tongue
Clinical considerations
References

3. Introduction
"Tongue is barely three inches long but it can kill a person six feet tall"
Dr. BD Chaurasia's human anatomy
• Tongue is a muscular organ situated in the
floor of the mouth.
• Associated with the functions of taste,
speech, mastication and deglutition.
• Oral part Lies in the Mouth
• Pharyngeal part Lies in the pharynx
• These parts are separated by a
V-shaped sulcus Sulcus terminalis
Sulcus
terminalis
[
[

4. Development of tongue
Starts to develop near the end of the fourth week .
Anterior 2/3rd:
from 2 lingual swellings and one tuberculum impar,
which arise from first branchial arch.
supplied by lingual nerve and chorda tympani
Posterior 1/3rd:
from the cranial large part of the hypobranchial
eminence, i.e., from the third arch
supplied by glossopharyngeal nerve
Posterior most:
from the fourth arch
supplied by superior laryngeal nerve
Connective tissue develops from local mesenchyme.

5. Terminal
sulcus
Hypobrachial
eminence

7. • Some muscles probably differentiate in situ but most of
them are derived from myoblasts originating in the
occipital somites.
• This fact is supported by the fact that the tongue
musculature is innervated by the hypoglossal nerve.
• Palatoglossus develops from mesoderm of sixth arch
and is supplied by cranial root of accessory nerve
through pharyngeal plexus.
Origin of muscles of tongue

8. EXTERNAL FEATURES OF THE TONGUE:
1. A Root
2. A tip or apex
3. A body:
• A curved upper surface or
Dorsum (Oral and
Pharyngeal parts)
• An inferior surface or the
ventral surface (Oral part
only)

9. THE ROOT:
• Attached to the
mandible and soft palate
above, and to the hyoid
bone below.
• In between two bones, it
is related to the
geniohyoid and
mylohyoid muscles.
THE TIP:
• Forms the anterior free
end.
• At rest, it lies behind the
upper incisor teeth.

11. DORSUM OF THE TONGUE:
• It is convex in all directions.
It is divided in to:
a) Oral part or anterior two-
thirds or papillary part
b) Pharyngeal part or
posterior one-third
• Separated by faint v-shaped
groove: the sulcus
terminalis
• Two limbs of the ‘V’ meet at
a median pit: foramen
caecum (represents the site
from which the thyroid
diverticulum grows down in
the embryo)

12. • Located in the oral cavity and on its floor
• Has apex touching the incisor teeth
• Its margin is free and in contact with the gums & teeth
• In front of the palatoglossal arch, each margin shows 4-5
vertical folds, named the foliate papillae.
• The superior surface of the oral part shows a median
furrow and is covered with papillae which makes it
rough.
ORAL/PAPILLARY PART

13. • Lies behind to the palatoglossal arches and sulcus
terminalis.
• Its posterior surface, forms the anterior wall of oropharynx
• Mucous membrane is devoid of papillae.
• Has many lymphoid follicles that collectively constitute the
LINGUAL TONSIL, part of waldeyers ring.
• Mucous glands are also present.
Pharyngeal / lymphoid part /postsulcal part

14. • The posteriormost part of the tongue is connected to the
epiglottis by three-folds of mucous membrane-the median
glossoepiglottic fold and the right and left lateral
glossoepiglottic folds.
• On either side of the median fold, there is a depression
called the vallecula.
• The lateral folds seperate the vallecula from the piriform
fossa.

16. • Covered with a smooth mucous membrane, which shows a
median fold called the frenulum linguae.
• On either side of the frenulum, there is a prominence
produced by the deep lingual veins.
• Lateral to the vein is a fringed plica fimbriata ,directed
antero-medially towards the tip of the tongue.
INFERIOR SURFACE

18. PAPILLAE OF THE TONGUE:
These are projections of mucous membrane or corium which give
the anterior two- thirds of the tongue its characteristic roughness by
the presence of 4 types of papillae:
filiform, fungiform, foliate and vallate papillae
Filiform papillae:
• conical projections that give rise to velvety appearance of the tongue.
• located along the entire dorsum of the tongue, but they are not
involved in taste sensation.
• Smallest and most numerous
• Each is pointed and covered with keratin: the apex is often split into
filamentous processes.

19. Foliate papillae:
• small folds of mucosa located just in front of palatoglossal arch along
the lateral surface of the tongue
Fungiform papillae:
• Numerous near the tip and margins of the tongue
• Smaller than vallate papillae but larger than filiform papillae
• visible as discrete pink or bright red pinheads
• Narrow pedicle and large rounded head
• more numerous towards the edge of the tongue
• each bears a few taste buds

20. Circumvallate/ Vallate papillae:
• large in size 1-2 mm in diameter and are 8-12 in number.
• arranged in the form of a V with apex pointing backwards,
in front of sulcus terminalis.
• each is a cylindrical projection surrounded by a circular
sulcus and walls of the papilla are raised above the surface.

22. Glands of Von-Ebner
• They are serous salivary glands
• Located adjacent to the moats
surrounding the circumvallate and
foliate papillae
• Von Ebner's glands secrete lingual
lipase
• This secretion flushes material from
the moat to enable the taste buds to
respond rapidly to changing stimuli
• Von Ebner's glands are innervated by
cranial nerve IX, the
glossopharyngeal nerve.

23. Glands of
Blandin-Nuhn
• Anterior lingual glands (also called
apical glands) are deeply placed
seromucous glands that are located
near the tip of the tongue on each
side of the frenulum linguae.
• They are found on the under surface
of the apex of the tongue, and are
covered by a bundle of muscular
fibers derived from the Styloglossus
• They are between 12 to 25 mm. in
length, and approximately 8 mm.
wide, and each opens by three or
four ducts on the under surface of the
tongue's apex
Glands of Weber
• They lie along the lateral
border of the tongue
• These glands are pure
mucous secreting glands.
• These open into the crypts of
the lingual tonsils on the
posterior tongue dorsum.
• Abscess formed due to
accumulation of pus and
fluids in this gland is called
Peritonsillar Abscess

25. Muscles of the tongue
Intrinsic muscles:
• Superior longitudinal
• Inferior longitudinal
• Transverse
• Vertical
Extrinsic muscles:
• Styloglossus
• Hyoglossus
• Genioglossus
• Palatoglossus
A middle fibrous septum divides tongue into right and left halves. Each
half contains four intrinsic and four extrinsic muscles.

26. • Superior longitudinal muscle:
– lies beneath mucous membrane
– shortens the tongue, makes its
dorsum concave.
• Inferior longitudinal muscle:
– lying close to the inferior
surface of the tongue
– between genioglossus and
hyoglossus
– shortens the tongue, makes its
dorsum convex
Intrinsic Muscles
Occupy upper part of the tongue.
Attached to the submucous fibrous layer and to the median
fibrous septum.
Alter the shape of the tongue.
Inferior
longitudinal

27. • Transverse muscle:
– extends from median
septum to the margins
– makes the tongue
narrow and elongated
• Vertical muscle:
– found at the borders
of the anterior part of
the tongue
– makes the tongue
broad and flattened

28. Extrinsic Muscles
The extrinsic muscles are
• Genioglossus – connects tongue to the mandible
• Hyoglossus-connects tongue to the hyoid bone
• Styloglossus-connects tongue to the styloid process
• Palatoglossus-connects tongue to the palate

29. • Fan shaped muscle
• Forms bulk of the tongue
 ORIGIN-
upper genial tubercle of mandible.
 INSERTION-
• Upper fibres: tip of the tongue
• Middle fibres: dorsum
• Lower fibres: hyoid bone
 ACTIONS
• Upper fibres: retract the tip
• Middle fibres: depress the tongue
• Lower fibres: pull the posterior part
forward
(thus protrusion of the tongue from
the mouth)
GENIOGLOSSUS

30.  ORIGIN
• Greater cornu, front of lateral
part of body of hyoid bone
 INSERTION
side and inferior aspect of tongue
 ACTION
Depresses And Retracts The
Tongue
HYOGLOSSUS

31.  ORIGIN
styloid process of temporal bone
and stylohyoid ligament
 INSERTION
side and inferior aspect of
tongue
 ACTION
Pulls the tongue upwards and
backwards during swallowing.
STYLOGLOSSUS

32.  ORIGIN
Oral surface of palatine
aponeurosis of soft palate
 INSERTION
side of tongue (junction of oral
and pharygeal part)
 ACTION
Pulls up root of tongue,
approximates palatoglossal
arches, closes oropharyngeal
isthmus
PALATOGLOSSUS

33. Vascular supply of the tongue
• Tongue is supplied
by the lingual
artery which is a
branch of external
carotid artery
• Root of the tongue
is also supplied by
tonsillar artery
which is a branch
of facial artery and
ascending
pharyngeal branch
of external carotid

34. • Venous tributaries
– accompanying the lingual
artery and hypoglossal nerve
• The deep lingual vein is
the largest and principal
vein of the tongue
• These veins unite to
form the lingual vein
which ends in the
internal jugular vein

35. Lymphatic Drainage
1. The tip of the tongue drains bilaterally into submental
nodes.
2. The right and left halves of the remaining part of the
anterior two-thirds of the tongue drain unilaterally to the
submandibular nodes. A few central lymphatics drain
bilaterally to the same nodes.
3. The posterior one-third of the tongue drains bilaterally to
the jugulo-omohyoid nodes [lymphnodes of tongue]
4. The posterior most part drains bilaterally into the upper
deep cervical lymph nodes.

36. Lymphatic drainage

37. Nerve Supply
 Motor: all muscles of the tongue (intrinsic and extrinsic) are
supplied by hypoglossal nerve except palatoglossus which is
supplied by pharyngeal plexus.
 Sensory:
anterior 2/3 of the tongue:
general sensation: lingual nerve - branch of the
mandibular nerve (with cell bodies in the trigeminal
ganglion)
taste: chorda tympani (with cell bodies in the geniculate
ganglion of facial nerve) except vallate papillae.Vallate
papillae is supplied by glossopharyngeal nerve.
parasympathetic secretomotor fibres to the anterior
lingual gland run in the chorda tympani from the
superior salivary nucleus, and relay in the
submandibular genglion

38. – posterior 1/3 of the tongue: innervated by the
glossopharyngeal nerve (both general sensation
and taste), with cell bodies in the glossopharyngeal
ganglia in the jugular foramen.
– posterior most part of the tongue: innervated by
the vagus nerve through the internal laryngeal
branch (with cell bodies in the inferior vagal
ganglion)

39. Innervation of the tongue

40. • The peripheral organs of gustation are the
taste buds ,composed of modified epithelial
cells set in piriform groups within the epithelia
of the tongue , soft palate, palatoglossal
arches ,posterior epiglottic surface and
posterior wall of oropharynx.
GUSTATORY APPARATUS

41. Taste buds
• Most numerous in vallate
papillae, also abundant over the
foliate papillae and on posterior
third of tongue.
• Sparsely scattered on the lingual
fungiform papillae, soft palate,
epiglottis and pharynx.
• Occur greater number in infants,
gradually atrophy with age.
• No taste buds in central region of
the dorsum of the tongue.

42. STRUCTURE
• Flask-like in shape with its base
resting on the corium and neck
opening by an orifice, the gustatory
pore, between the cells of the
epithelium.
• The peripheral end of the cell
terminates at the gustatory pore in a
fine hair-like filament, the gustatory
hair.

43. The supporting cells are mostly arranged
like the staves of a cask, and form an
outer envelope for the bud. Some,
however, are found in the interior of the
bud between the gustatory cells.
The gustatory cells occupy the central
portion of the bud; they are spindle-
shaped, and each possesses a large
spherical nucleus near the middle of the
cell. At their basal ends the gustatory cells
form synapses with nerves that project to
the brain.
The Basal cells are present at the base of
the taste bud. They act as stem cells for
renewal of taste cells and supporting
cells.

44. • NEUROLOGY
• Nerve fibres reaching the taste buds from the
subepithelial plexus are complex in their
distribution in the tongue, as deduced by
recordings from individual nerve fibres in the
proximal fasciculi of the chorda tympani and
glossopharyngeal nerve.
• Each fibre may have many terminals, spreading to
innervate widely seperated taste buds and more
than one sensory cell in each bud.

45. Taste discrimination
• Gustatory receptors detect five
main types of taste sensation
• Sweet: tip
• Sour: middle
• Salty: anterolateral
• Bitter: base
• Umami: evenly distributed
throughout tongue

46. • The fifth taste sense, umami, was recently added to
the four classic tastes. This taste has been known for
almost 100 years, but it became established once its
receptor was identified. It is triggered particularly by
the monosodium glutamate (MSG).
• However recent evidence indicates that all areas
of tongue are responsive to all taste stimuli

47. • Bulk of tongue—striated muscle
• Mucous membrane—have a layer of connective tissue
lined by stratified squamous epithelium.
• Numerous gland ,both serous and mucous lies deep to
the mucous membrane.
Histology

48. TASTE PATHWAY
• Taste from anterior 2/3 except vallate papillae carried by
chorda tympani till geniculate ganglion.The central processs
go to the tractus solitarius in the medulla.
• Posterior 1/3(including vallate papillae)- carried by 9th
cranial nerve till inferior ganglion. Central process also
reach tractus solitarius.
• Posterior most part- vagus nerve till inferior ganglion of
vagus. Central process also reach tractus solitarius.

49. • After the relay in tractus
solitarius, the solitario-thalamic
tract is formed which becomes
a part of trigeminal lemniscus
and reaches postero-
ventromedial nucleus of
thalamus of the opposite side.
• Another relay takes them to
lowest part of post central
gyrus,which is the area of taste.

50. • Injury to hypoglossal nerve paralysis of the muscles on the side of
lesion
• Tongue deviates to paralyzed side during protrusion due to
action of unaffected genioglossus muscles
• Others
infranuclear lesion (i.e., in motor neuron disease and in
syringobulbia): gradual atrophy and muscular twitchings of
the affected half of the tongue observed
supranuclear lesion (i.e., in pesudobulbar palsy): produce
paralysis without palsy (tongue is stiff, small and moves
sluggishly)
• Glossitis usually a part of generalized ulceration of mouth
cavity or stomatitis.
• Acute glossitis enormous swelling due to presence of
lymphatics and rich areolar tissue
Applied anatomy

51. • Under surface jaundice
• Unconscious patient tongue may fall back & obstruct the air
passages
• Grand mal epilepsy - tongue bitten during attacks
• Carcinoma of tongue is quite common.
• Reffered pain in ear- diseases of posterior part of tongue.
Sublingual absorption of drugs
• For quick absorption, pill or spray is put under the tongue
where it dissolves and enter the lingual veins (nirtroglycerin in
angina pectoris)

52. • Aglossia & microglossia syndrome
• Macroglossia
• Ankyloglossia /tongue tie
• Cleft tongue
• Fissured tongue
• Median rhomboid glossitis
• Benign migratory glossitis
• Lingual varices
• Lingual thyroid nodule
Anomalies of the tongue

53. • Aglossia-complete absence of
tongue at birth
• Microglossiapresence of small
rudimentary tongue
• Patient encounters difficulty in
eating , speaking and airway
problems.
• Associated with oromandibular limb
hypogenesis syndrome and
hypomelia and Pierre Robin
syndrome.
Aglossia & microglossia

54. • Tongue enlargement,which
leads to functional and
cosmetic problems.
• Down syndrome / Beckwith
wiedmann syndrome
• Congenital macroglossia /
acquired macroglossia
• Relative/apparent
macroglossia
• Surgical intervention is the
treatment of choice.
Macroglossia

55. • Inferior frenulum attaches
to the bottom of the tongue
& restricts the movement of
the tongue.
• Feeding problems in infants
• Speech abnormalitiess –
lisping and inability to
pronounce certain sounds
and words.
• Frenulectomy is
recommended
Ankyloglossia / Tongue tie

56. • cleft or bifid tongue is rare which
might occur due to lack of fusion of
the lateral halves.
• Partial cleft tongue is more common
• Food debris and micro organisms may
collect in the base of cleft and cause
irritation.
• Seen with Orofacial digital syndrome
• Regular cleaning of tongue should be
carried out.
Cleft tongue

57. • Grooves of varying depth are
noted along the dorsal &
lateral aspect of the tongue.
• Melkersson rosenthal
syndrome / Down syndrome
• Polygenic or autosomal
dominant mode of inheritance
is suspected
• No definitive therapy or
medication is required
Fissured tongue

58. • Developmental defect
resulting from an incomplete
desent of tuberculum impar
and entrapment of a portion
between fusing lateral
halves of the tongue.
• Also called central papillary
atrophy of tongue.
• Prone to candida infection
Median rhomboid glossitis

59. • Irregularly shaped reddish
areas of depapillation and
thinning of dorsal tongue
epithelium which is surrounded
by a narrow zone of
regenerating papillae that are
whiter than the surrounding
tongue surface.
• Found with increased
frequency in person with
psoriasis of the skin.
Benign migratory glossitis

60. • Hypertrophy of filiform papillae
• Brown,black white,green in
colour
• Poor oral hygiene
• Filiform papillae can increase
upto 15 mm in length
• Reported in patients of HIV
• Treatment involves tongue
scraper, surgical removal of the
papillae using electrodesication,
carbon dioxide laser or even
scissors.
• Prognosis is excellent
Hairy tongue

61. • Varices involving lingual veins
are relatively common.
• Appears red or purple shot like
clusters of vessels on ventral
surface & lateral borders of
the tongue as well as the floor
of mouth.
• Thrombosis of varices is
frequent in occurrence.
Lingual varices

62. • Anomalous condition in which
follicles of thyroid tissue are
found in the substance of the
tongue .
• Manifested clinically as a
nodular mass in or near the
base of the tongue in the
general vicinity of foramen
caecum.
• Managed by suppressive
thyroxin or by surgical excision.
Lingual thyroid nodule

63. • Gray’s anatomy 37th edition
• Grant’s atlas of anatomy 12th edition
• Bd charausia 3rd edition
• Shaefer’s textbook of oral pathology – 5th
edition
References