ANATOMY & PHYSIOLOGY

1. 1BRISSO ARACKAL

2. 2BRISSO ARACKAL

3. ANATOMY AND PHYSIOLOGY
OF TONGUE
 Brisso Arackal
3BRISSO ARACKAL

4. Anatomy
Of
Tongue
4BRISSO ARACKAL

5. 5BRISSO ARACKAL

6. CONTENTS
 Introduction
 Parts of Tongue
 Muscles of tongue
 Intrinsic muscles
 Extrinsic muscles
 Attachment
 Blood supply
 Nerve supply
 Lymphatic drainage
6BRISSO ARACKAL

7. Introduction
 Voluntary muscular structure
 Occupies floor of mouth
 3 inch long.
 Superior surface consist of stratified squamous
epithelium with numerous papillae contains
sensory receptors for the sense of taste in taste
bud.
7BRISSO ARACKAL

8. Parts of the Tongue
 Root
 Located between the hyoid bone and
mandible.
 Dorsal portion sits in the oropharynx.
 Attaches the tongue to roof of the
mouth.
 Body
 Makes up the anterior two-thirds of the
tongue.
 Rough surface due to the lingual
papillae.
 Surrounded by anterior and lateral
teeth.
 Mobile portion of the tongue.
 Apex
 Also known as the tip, is the anterior
one-third of the anterior tongue surface.
 Rests against the incisor teeth.
 Highly mobile.
8BRISSO ARACKAL

9. 9BRISSO ARACKAL

10. Surface of the Tongue
 The top of the tongue (superior
surface) has a V-shaped line
known as the terminal sulcus
that divides the tongue into the
anterior and posterior surfaces.
 The anterior surface is made
up of the apex at the tip and
body.
 The posterior surface is made
up entirely of the root.
 The inferior surface of the
tongue (underside) is also
made up of the body and apex.
10BRISSO ARACKAL

11. 11BRISSO ARACKAL

12. 12BRISSO ARACKAL

13. MUSCLES OF TONGUE
A median fibrous septum divides the tongue into Rt. & Lt.
halves. Each half contains 4 intrinsic & extrinsic muscles.
Intrinsic muscles Extrinsic muscles
 Superior longitudinal
 Inferior longitudinal
 Transverse
 Vertical
 Genioglossus
 Hypoglossus
 Styoglossus
 Palatoglossus
13BRISSO ARACKAL

14. 14BRISSO ARACKAL

15. INTRINSIC MUSCLES
 Occupy the upper part of tongue and attached to the
submucous fibrous layer and to median fibrous
septum.
 Alter the shape of tongue.
 4 in no. they are
 1. Superior longitudinal
 2. Inferior longitudinal
 3. Transverse
 4. Vertical
15BRISSO ARACKAL

16.  Superior longitudinal-
 beneath the mucous membrane.
 Shortens the tongue.
 Make dorsum concave.
 Inferior longitudinal-
 Lying close to inferior surface of
tongue between genioglossus
and hypoglossus.
 Shortens the tongue.
 Makes its dorsum convex.
 Transverse-
 Extend from median septum to
the margins.
 Makes the tongue narrow and
elongated.
 Vertical-
 Found at the borders of anterior
part of tongue it make tongue
broad & flattened.
16BRISSO ARACKAL

17. EXTRINSIC MUSCLES
 4 in no. they are
 1. Genioglossus
 2.Hyoglossus
 3. Palatoglossus
 4. Styoglossus
 Connect to the tongue
to mandible by
Genioglossus, hyoid
bone via Hyoglossus,
Styloid process viz.
Styloglossus and palate
via Palatoglossus.
17BRISSO ARACKAL

18. 18BRISSO ARACKAL

19. Genioglossus-
Fan shaped, form main bulk
of tongue.
 Origin-
 Upper genial tubercle of
mandible which run
backward.
 Inserted-
 Upper fiber--tip-retracted
the tip of tongue
 Middle fiber-dorsum-
depress tongue
 Lower fiber- hyoid bone-
pull posterior part of
tongue forward and
protrude out.
19BRISSO ARACKAL

20. 20BRISSO ARACKAL

21. Hyoglossus-
 Origin-
 Whole length of greater
cornua and lateral part of
body of hyoid bone.
 Fibers run upward and
forwards.
 Insertion-
 Side of tongue between
Styloglossus and inferior
longitudinal muscle of
tongue.
 Action- depresses tongue
makes dorsum convex retracts
and protruded tongue.
21BRISSO ARACKAL

22. 22BRISSO ARACKAL

23. Palatoglossus-
 Origin-
 Oral surface of palatine
aponeurosis.
 Insertion-
 Descends in the
Palatoglossus arch to the
side of tongue at junction of
its oral and pharyngeal
parts.
 Action-
 Pulls up the root of tongue,
approximates the
Palatoglossus arches and
thus closes the
oropharyngeal isthmus.
23BRISSO ARACKAL

24. 24BRISSO ARACKAL

25. Styoglossus-
 Shortest and smallest
 Origin-
 Styloid process of
temporal bone
 Insertion-
 Tip and sides of tongue
 Action-
 Retraction and
elevation of tongue
25BRISSO ARACKAL

26. 26BRISSO ARACKAL

27. Blood supply
 External carotid artery- lingual branch
 Lingual vein- joins to internal jugular vein
 Root of tongue- tonsillar and ascending pharyngeal
arteries.
27BRISSO ARACKAL

28. Nerve supply of muscles-
 Four extrinsic and 3
intrinsic muscles of
tongue are supplied
by IX C.N.
 Only palatoglossus
supplied by vago-
accessory complex.
28BRISSO ARACKAL

29. Lymphatic drainage-
 Tip of tongue-
 Drains bilaterally to the
sub mental nodes.
 Remaining part-
 Ant. Rt. & lt. 2/3 drains
unilaterally to the
submandibular nodes.
 Few central lymphatics
drains bilaterally to same
nodes
 Post. 1/3 drains bilaterally
to the jugulo-omohyoid
nodes.
29BRISSO ARACKAL

30. PHYSIOLOGY
OF
TONGUE
30BRISSO ARACKAL

31. CONTENTS…
 Taste buds
 Location
 Structure
 Papillae
 Types of papillae
 Physiology of taste
 Neural pathways for taste
 Function of tongue
31BRISSO ARACKAL

32. Taste Bud
 Taste buds are sensory organs that are found on
your tongue and allow you to experience tastes that are
sweet, salty, sour, and bitter
 The sense of taste called gustation.
 10,000 taste buds are present in its papilla.
 A papilla contains few to 100 taste buds.
32BRISSO ARACKAL

33. 33BRISSO ARACKAL

34. Location of Taste Buds
 Taste buds contains sensory receptors found in the
papillae of tongue and widely distributed in the
epithelium of tongue, soft palate, pharynx and
epiglottis.
34BRISSO ARACKAL

35. Structure of Taste Buds
 Oval barrel shape
70um*50um.
 Life span- 10 days
 Having opening
called taste pores
 Composed of 5-15
gustatory receptors
cell, 40 supporting
cells or
subtentacular cell
and 15-20
transitional cells.
35BRISSO ARACKAL

36. Electron microscopic structure of
taste buds
36BRISSO ARACKAL

37. Papillae
 The majority of taste buds on the tongue sit on raised
protrusions of the tongue surface called papillae.
37BRISSO ARACKAL

38. Types of papillae
38BRISSO ARACKAL

39. Fungiform papillae
 As the name suggests,
these are slightly
mushroom-shaped if
looked at in longitudinal
section.
 These are present mostly
at the apex (tip) of the
tongue, as well as at the
sides.
 Innervated by facial
nerve.
39BRISSO ARACKAL

40. 40BRISSO ARACKAL

41. Filiform papillae
 These are thin, long
papillae.
 "V"-shaped cones
 That don't contain taste
buds but are the most
numerous. These papillae
are mechanical and not
involved in gustation.
 They are characterized by
increased keratinization.
41BRISSO ARACKAL

42. Foliate papillae
 Foliate papillae are short
vertical folds found on the
lateral margins of the tongue.
 They are occasionally
Misdiagnosed as tumors or
inflammatory disease. They
are usually bilaterally
symmetrical. Sometimes they
appear small and
inconspicuous, whereas they
may be prominent. Lingual
tonsils are found immediately
beneath the foliate papillae
and, when hyperplastic,
cause a prominence of the
papillae.
42BRISSO ARACKAL

43. Circumvallate papillae or vallate p.
 10 to 14 in no.
 Present at the back of the
oral part of the tongue.
 They are arranged in a
circular-shaped row just in
front of the sulcus
terminalis of the tongue.
 They are associated with
ducts of Von Ebner's
glands.
 innervated by the
glossopharyngeal nerve.
43BRISSO ARACKAL

44. Cont…
 It is generally accepted that there
are four taste sensations, recently
a fifth basic taste has been
added: Sweet, sour, salty, bitter
and the recently added umami
(used in Asian kitchens produced
by monosodium glutamate).
 Salts, sweet, sour and umami
tastes causes depolarization of
the taste cells. Although different
mechanisms are applied.
 Bitter causes an internal release
of Ca2+, no external Ca2+ is
required.
44BRISSO ARACKAL

45. Physiology of Taste
 The gustation involves stimulation of chemoreceptors
by dissolved chemicals.
 The sensory receptors are stimulated by chemicals that
enter the pores dissolved in saliva.
 Nerve impulses are generated and conducted along the
glossopharyngeal from post.1/3rd, facial from ant. 2/3
tongue and vagus nerves from pharyngeal wall before
synapsing in medulla and thalamus.
 Their final destination is the taste area in the parietal
lobe of the cerebral cortex where taste is perceived.
45BRISSO ARACKAL

46. 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
46BRISSO ARACKAL

47. 47BRISSO ARACKAL

48. Neural pathways for taste-
 The primary sensory neurons carrying taste sensation
from taste buds are located in geniculate ganglion ,
superior petrosal ganglion and inferior ganglion (
ganglion nodosum) of facial glossopharyngeal and
vagus nerves respectively.
 The peripheral processes of these cells connect with
the taste buds, while central processes end in nucleus
tractus solitarius (NTS).
48BRISSO ARACKAL

49. Conti…..
 The secondary order sensory neurons arise from
nucleus tractus solitarius, cross the midline, turn
upwards to join the medial lemniscus and terminate in
the posteroventral nucleus of thalamus.
 The third order sensory neurons arise from
posteroventral nucleus of thalamus and project in the
inferior part of the post central gyrus of the parietal
lobe of the brain, the taste area of the cerebral cortex.
49BRISSO ARACKAL

50. 50BRISSO ARACKAL

51. Function of Tongue
 Mastication
 Deglutition
 Speech
 Taste
51BRISSO ARACKAL

52. 52BRISSO ARACKAL

53. 53BRISSO ARACKAL

54. 54BRISSO ARACKAL