ANATOMY & DEVELOPMENT OF TONGUE

1. TONGUE

2.  The tongue is a mobile muscular
organ situated in the floor of the
mouth.

3. Functions
Taste
Speech
Mastication
Deglutition

4. External Features
PARTS
ROOT
TIP
BODY
DORSUM
INFERIOR
SURFACE

6. Root
Root of Tongue Attached to –
 Above - Styloid Process & Soft
Palate
 Below – Mandible & Hyoid bone

7. TIP
Anterior free end, lies behind upper
incisors.

8. Body
Dorsum
 Oral Part
 Pharyngeal Part
 Posterior most Part
Inferior Surface

10. BODY
The bulk of tongue between the
root and tip is called body.
 It has dorsal and ventral
surfaces and right and left
lateral margins.

11. Dorsal surface
 It is divided by a V-shaped
sulcus, the sulcus terminalis into
two parts, viz.
1. Anterior two-third or oral part.
2. Posterior one-third or pharyngeal
part.

13. The apex of the sulcus
terminalis is marked by a blind
foramen, FORAMEN CAECUM,
which indicates the point of
origin of the thyroglossal duct
in IUL.

14. The oral part presents the
following features:
1. A Median Furrow, representing
the bilateral origin of the
tongue.
2. Large number of Papillae.

15. The pharyngeal part presents
the following features:
1. A large number of lymphoid
follicles, which together
constitute the lingual tonsil.
2. A large number of mucus and
serous glands.

16. Papillae Of The Tongue
 These are projections of
mucuos membrane which gives
the anterior 2/3rds of the tongue
its characteristic roughness.

18. Vallate Papillae
 Largest papillae
Size- 1-2 mm in diameter.
8 to 12 in number.
Arrange in V-shaped row in
front of sulcus terminalis

19. Filiform papillae
Smallest & Devoid of taste buds.
Conical projections with sharply
pointed tips.
 Filiform papillae are located
abundantly on the dorsum of
tongue and responsible for its
velvety appearance.

20. Fungiform papillae
 These are mushroom shaped, numerous
near tip & margins of tongue.
 They are visible as discrete red pinheads.

21. Foliate Papilla
 Vertical grooves & ridges on
lateral border in front of sulcus
terminalis.
Rudimentry in humans.

22. Pharyngeal Part
Posterior 1/3rd
Lies behind the palatoglossal
arches.

23. Devoid of papillae but appears
rough due to the presence of
numerous lymphatic follicles in
the underlying submucosa, that
collectively termed lingual tonsil.

24. Inferior surface of the tongue
1. Frenulum linguae: a median-fold
of mucus membrane connecting
the tongue to the floor of the
mouth.

26. 2. Deep lingual veins: on either
side of frenulum linguae (lingual
nerve & lingual artery are medial
to the vein but not visible).
3. Plica fimbriata: a fimbriated fold
of mucous membrane lateral to
the lingual vein.

27. Muscles of the Tongue
ExtrinsicIntrinsic

28. INTRINSIC MUSCLES
4 paired intrinsic muscles
originate and insert within the
tongue.
No attachment outside the tongue.
These muscles alter the shape of
the tongue.

30. INTRINSIC MUSCLES
 Superior longitudinal
Inferior longitudinal
Transverse
Vertical

31. Origin: submucous fibrous layer
& median fibrous septum
Insertion: mucous membrane.

32. superior
longitudinal
beneath the
mucous
membrane
• shortens the
tongue
• makes the
dorsum
concave
inferior
longitudinal
close to inferior
surface between
genioglossus
and hyoglossus
• shortens the
tongue
• makes the
dorsum convex
transverse extends from
median septum
to the margin
makes the tongue
narrow
and elongated
vertical at the border of
the anterior part
of the tongue
makes the tongue
broad and
flattened

33. Movements
 Intrinsic Muscles
Superior Longitudinal : shortens the
tongue, makes the dorsum concave
Inferior longitudinal : shortens the
tongue, makes the dorsum convex
Transverse : makes the tongue narrow
and elongated
Vertical : makes the tongue broad
and flattened

34. Movements
 Extrinsic Muscles
Genioglossus : Protrusion
 Styloglossus: Retraction
 Hyoglossus: Depression
 Palatoglossus: Elevation

35. EXTRINSIC MUSCLES
 Genioglossus: superior genile
tubercle
 Hyoglossus: greater cornu of
hyoid bone
 Styloglossus: styloid process
 Palatoglossus: palatine
aponeurosis

36. Genioglossus superior
genile
tubercle
whole of
the tongue
& hyoid
bone.
•Protrudes the tongue
when acting together
with its counterpart of
opposite side
Hyoglossus greater cornu
of hyoid bone
& adjecent
part of hyoid
bone
Side of
tongue
•Depresses the sides
of the tongue
•Makes the dorsal
surface convex
Styloglossus Tip of styloid
process
Side of
tongue
•Draws the side of the
tongue upwards and
backwards
Palatoglossus Oral surface
of palatine
aponeurosis
Side of
tongue
•Pulls up the root of
the tongue
•Approximates
palatoglossal arches

38. VASCULAR SUPPLY

39. ARTERIAL SUPPLY
 Lingual artery: divides into :
 Dorsal lingual artery
 Deep lingual artery
 Sublingual artery
Tonsillar branch of the facial
artery.
Ascending pharyngeal artery.

41. VENOUS DRAINAGE
Deep lingual vein is the principal
vein
Venae comitantes accompanying
the lingual artery.
Venae comitantes accompanying
the hypoglossal nerve.
All these veins terminate into IJV.

42. LYMPHATIC DRAINAGE
 Tip - drain to submental nodes.
 The right and left halves of the
anterior 2/3rds drain in
submandibular nodes.
Posterior part & posterior most
part- drains to deep cervical
nodes.
Whole lymph finally drain into
jugulo-omohyoid LN.

44. Development of tongue
Development begins at the 4th
week of IUL.
The tongue develops in relation
to the1,2,3,4 pharyngeal arches
in the floor of the developing
mouth.

46. At the end of the 4th week of IUL, a
small median triangular swelling
called Tuberculum Impar develops in
the floor of primitive pharynx, just
cranial to Foramen Cecum.
Soon after this, two lateral oval
swellings called Lingual Swellings
develop on each side of tuberculum
impar.

49. Caudal to tubercular impar,
another large median swelling
called hypobranchial
eminence (copula of His)
develops in the floor of primitive
pharynx in relation to 3,4
pharyngeal arches.

50. The hypobranchial eminence
soon subdivides into large
cranial part and small caudal
part.

51.  Posterior 1/3 of the tongue:
The posterior one-third of the
tongue including circumvallate
papillae develops from cranial
part of hypobranchial eminence.

52. The posterior most part of the
tongue and epiglottis develop
from the caudal part of the
hypobranchial eminence.

53. Development of Musculature of
tongue:
Derived from occipital
myotomes
 Nerve supply is by hypoglossal
nerve.

54. NERVE SUPPLY
Motor supply: All the muscles
of tongue are supplied by the
Hypoglossal Nerve except
palatoglossus which is supplied by
cranial root of accessory via
pharyngeal plexus.

55. Sensory supply
Anterior
2/3rd except
circumvallate
papillae
Posterior
1/3rd
&
circumvallate
papillae
Posteri-
or most
part
General
sensations
Lingual
nerve
Glossopha
-ryngeal
nerve
Vagus nerve
through
internal
laryngeal
branch
Special
sensations
Chorda
tympani
Glossoph-
ryngeal
Vagus
nerve

56. APPLIED ANATOMY
Aglossia: absence of tongue.
Hemiglossia: half tongue:- It occurs
if one of the lingual swelling fails to
develop.
Microglossia: Tongue is too small.
Macroglossia: Tongue is too large.

57. Tongue tie (ankyloglossia): when
frenulum of tongue extends to the
tip of the tongue, thus preventing its
protrusion and causing difficulty in
speech.
Bifid tongue: In this condition, the
anterior portion of the tongue splits
into two parts.