1) The tongue is a muscular organ located in the oral cavity that has roles in taste, speech, chewing, swallowing, and mouth cleansing. It contains both intrinsic and extrinsic muscles. 2) The tongue has several parts including the root, tip, body, and dorsum. The dorsum has oral and pharyngeal parts that differ in structure and function. It is covered in papillae that give it a rough texture and aid in taste. 3) The tongue receives its motor innervation mainly from the hypoglossal nerve and sensory innervation from the lingual, chorda tympani, and glossopharyngeal nerves. Its blood supply is from the lingual artery and it

1. Dr Gajendra Gangadhar Gurav
Associate Professor
Department of Rachana Shaarir
Govt. Ayurved College Junagadh

3. Introduction
• Tongue is mobile muscular organ located partly in the Oral
cavity and partly in the Oropharynx(in the floor of mouth). It
is attached to the hyoid bone below, to the palate above, to the
mandible in front and to the styloid process behind by means
of muscles.
• Tongue is associated with the functions of
i) Taste ii) Speech iii) Chewing iv) Deglutition
v) Cleansing of mouth.
• Tongue is the peculiar organ, where stratified squamous non-
keratinized mucosa closely covers a mass of striated muscles
fibers disposed in vertical, transverse and longitudinal
directions. The substance of tongue is divided into two halves
by a median fibrous septum.

9. External features:
Parts of tongue:
i) Root: The root of tongue lies in the floor of the mouth and it
is attached to the styloid process and soft palate above, and to
mandible and hyoid bone below. It is composed of
genioglossus and Hyoglossus muscles .
ii) Tip: The Tip of the Tongue forms the anterior free end
which is directed forwards and at rest behind the upper incisor
teeth.
iii) Body: A Body has:
A) A Curved Upper surface or Dorsum of Tongue
B) An Inferior surface.
A) Dorsum of Tongue: It is convex in all direction directions. It
is divided into:
a) An oral part or Anterior 2/3rd of dorsum of tongue.
b) A Pharyngeal part or Posterior 1/3rd of the tongue, by a
faint V-shaped groove, Sulcus terminalis.

10.  The two limbs of ‘V’ meet at a median pit, named the
foramen caecum. They run laterally and forwards up to the
palatoglossal arches.
 The foramen caecum represents the site from which the
Thyroid diverticulum grows down in the embryo. The Oral and
Pharyngeal parts of the Tongue differ in their development,
topography, structure and function.
c) Small Posteriormost Part.

11. Oral or Papillary Part of the Tongue:
• It is placed on the floor of the mouth. Its margin are free and in
contact with the gums and teeth. Just in front of palatoglossal
arch, each margin shows 4 to 5 vertical folds, named the Foliate
Papillae.
• The Superior surface of the oral part shows a median furrow
and is covered with papillae which make it rough.
• The Inferior surface is 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. More laterally there is a fold called the
Plica Fimbriata that is directed forward and medially towards
the tip of the Tongue.
 Pharyngeal or Lymphoid Part of the Tongue:
• It lies behind the palatoglossal arches and Sulcus terminalis. Its
posterior surface, sometimes called the Base of the tongue, forms
the Anterior wall of oropharynx.

12. • The mucous membrane has no papillae, but has many lymphoid
follicles that collectively constitute the lingual tonsils. Mucous
gland are also present.
 Posteriormost of the Tongue:
• It is connected to the epiglottis by a three folds of mucous
membrane. These are 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 separate the Vallecula from the
Piriform fossa.
Clinical Anatomy of Tongue:
• Glossitis is usually a part of generalized ulceration of the mouth
cavity or Stomatitis. In certain anaemias, the Tongue becomes
smooth due to atrophy of the filiform papillae.
• The presence of a rich network of lymphatics and of loose
areolar tissue in the substance of tongue is responsible for
enormous swelling of tongue in Acute Glossitis. The tongue fill
up the mouth cavity and then protrude out of it .

13.  The undersurface of the Tongue is a good site along with the
bulbar conjuctiva for observation of Jaundice.
 In unconscious patients, the tongue may fall back and
obstruct the air passages. This can be prevented either by lying
the patient on one each side with head down (Tonsil
Position) or by keeping the Tongue out mechanically.
 Lingual Tonsil in the Posterior 1/3rd of the Tongue forms part
of Waldeyer’s ring.
 Papillae of the Tongue:
These are projections of mucous membrane or corium
which give the Anterior 1/3rd of the Tongue, its characteristic
roughness. These are of three types:
a) Vallate or Circumvallate papillae: They are large in size
1-2mm in diameter and are 8-12 in number. They are
situated immediately in front of the Sulcus terminalis. Each
papilla is a cylindrical projection surrounded by a Circular
Sulcus. The walls of the papilla have taste buds.

16. b) Fungiform papillae: These are numerous near the Tip and
margins of the tongue, but some of them are also scattered
over the dorsum. These are smaller than the vallate papillae
but larger than the filiform papillae. Each papilla consists of a
narrow pedicle and a large rounded head. They are
distinguished by their bright colour.
c) Filiform Papillae or Conical Papillae:
It cover the presulcal area of the dorsum of the tongue, and
give it a characteristic velvety appearance. They are the
smallest and most numerous of the lingual papillae. Each is
pointed and covered with keratin; the apex is often split into
filamentous processes.
d) Foliate Papillae: These are present at the lateral border just
infront of circumvallate papillae. They are leaf shaped.

17. Muscles of the Tongue:
A middle fibrous septum divides the tongue into right and left
halves. Each half contains four intrinsic and four extrinsic
muscles.
Intrinsic Muscles:
They occupy the upper part of tongue , and are attached to the
Submucous fibrous layer and to the Median fibrous septum.
They alter the shape of the Tongue.
i) Superior Longitudinal:
• It arises from the fibrous tissue deep to the mucous membrane
on the dorsum of the tongue and Midline lingual septum.
• They pass longitudinal back from the tip of the tongue to its
root posteriorly.
• It inserts into the overlying mucous membrane.
• The Superior Longitudinal muscles act to elevate the Tip and
sides of the tongue superiorly. This shapes the tongue dorsum
into a concavity.

18. ii) Inferior Longitudinal:
• It originates from the fibrous tissue beneath the mucous
membrane stretching from tip of the tongue longitudinally
back to the root of the tongue and hyoid bone.
• They insert into the mucous membrane of the tongue dorsum.
It lies between the Genioglossus and Hyoglossus.
• Inferior longitudinal muscles act to curl the tip of the tongue
inferiorly. This make the dorsum of tongue convex in shape.
iii) Transverse:
• It lies as a sheet on the either side of the midline in a plane
that is deep to the Superior Longitudinal muscles but
superficial to Genioglossus.
• They run transversely from their origin at the fibrous lingual
septum to insert into the submucous fibrous tissue at the
lateral margin of tongue.
• Contraction of the transverse muscles act to narrow and
increase the depth of the tongue.

19. iv) Vertical:
It is found at the borders of the anterior part of the tongue.
Extrinsic Muscles:
a) Genioglossus b) Hyoglossus c) Styloglossus
d) Palatoglossus.
The extrinsic muscles connect the tongue to the mandible via
Genioglossus; to the hyoid bone through Hyoglossus; to the
styloid process via styloglossus; and palate via Palatoglossus.
Origin, insertion and action of these muscles are summarized in
tabular form below.

25.  Arterial supply of Tongue:
It is derived from the tortuous Lingual Artery, a branch of the
External carotid artery. The Root of the tongue is also supplied
by the Tonsillar artery, a branch of Facial artery, and
Ascending Pharyngeal branch of External Carotid artery.
 Venous drainage:
• The arrangement of the venae comitantes/ veins of the tongue is
variable. Two venae comitantes accompany the lingual artery
and one vena comitant accompanies the Hypoglosssal nerve.
• The Deep lingual vein is the largest and principal vein of the
tongue. It is visible on the inferior surface of the tongue. It runs
backwards and crosses the Genioglossus and Hyoglossus below
the Hypoglossal nerve.
• These veins unite at the posterior border of the hypoglossus to
form the lingual vein which end in the internal jugular vein.

27.  Lymphatic drainage:
• The tip of the tongue drains bilaterally to the submental
nodes.
• The Right and Left halves of the remaining part of the
Anterior 2/3rd of the tongue drain unilaterally into
Submandibular nodes. A few central lymphatics drains
bilaterally to the Deep cervical nodes.
• Posterior most part and posterior 1/3rd of the tongue drain
bilaterally into the upper deep cervical lymph nodes including
jugulodiagastric nodes.
• The whole lymph finally drains to the jugulo-omohyoid nodes.
These are known as the Lymph nodes of the tongue.
 Nerve supply:
Motor Nerves: All the intrinsic and extrinsic muscles, except
the palatoglossus are supplied by the Hypoglosssal nerve.
Palatoglossus is supplied by cranial root of the Accessory
nerve through pharyngeal plexus. So seven out of eight
muscles are supplied by XII nerve.

30.  Sensory Nerves:
The Lingual nerve is the nerve of general sensation and the
Chorda Tympani is the nerve of Taste for Anterior 2/3rd of
the tongue except Vallate papillae.
The Glossopharyngeal nerve is the nerve for both general
sensation and taste for the Posterior 1/3rd of the tongue
including the circumvallate papillae.
The Posteriormost part of the tongue is supplied by Vagus
nerve through the Internal laryngeal branch.
Clinical Anatomy of Tongue:
• Carcinoma of Tongue is quite common. The affected side of
the tongue is removed surgically. All the deep cervical lymph
nodes are also removed, i.e. block dissection of neck because
recurrence of malignant disease occurs in lymph nodes.
Carcinoma of Posterior 1/3rd of tongue is more dangerous due
to bilateral lymphatic spread.
• Sorbitrate is taken sublingually for immediate relief from
Angina pectoris. It is absorbed fast because of rich blood
supply of the tongue and bypassing of Portal circulation.

33. • Genioglossus is called the Safety muscles of the Tongue
because if it is paralysed, the tongue will fall back on the
oropharynx and block the air passage. During anaesthesia, the
tongue is pulled forward to clear the air passage.
• Genioglossus is the only muscle of tongue which protrudes it
forward. It is used for testing the integrity of Hypoglossal
nerve. If hypoglossal nerve of right side is paralysed, the tongue
on protrusion ill deviate to the right side. Normal left
Genioglossus will pull the base to the left side and apex will get
pushed to right side (Apex and Base lie on opposite ends).
• Loss of Taste Sensation in the Anterior 2/3rd of the dorsum
of tongue is seen in the lesion of the facial nerve proximal to the
origin of the Chorda tympani nerve or of the facial nucleus. The
loss of taste from Vallate papillae is due to lesion of
Glossopharyngeal nerve or its nucleus.
• Inspection of Dorsum of tongue: Helps the clinician in
diagnosis of not only diseases of tongue but also in the systemic
diseases.

34. i) Black hairy tongue is characteristic of AIDS.
ii) In inflammation of tongue (Glossitis) the tongue looks red.
iii) Apthous ulcer is a small painful ulcer usually on the tip, on
the inferior surface or the sides of the anterior 2/3rd of the
tongue.
iv) Excessive furring of the dorsum can occur due to
prolonged fever.
 The enlarged Lingual tonsil can be inspected by indirect
laryngoscopy.
 Congenital anomalies:
i) The lingual thyroid may present as around and red swelling
at the foramen caecum on the dorsum of the tongue or in the
substance of tongue.
ii) Aglossia is congenital absence of tongue.
iii) Ankyloglossia or Tongue-tie is due to short frenulum.
iv) Macroglossia or very large tongue is found in cretinism &
Down’s syndrome.

35. Histology of tongue:
• The bulk of tongue is made up of Striated muscles.
• The Mucous membrane consists of a layer of connective tissue
(Corium), lined by stratified squamous epithelium.
• On the Oral part of the dorsum, mucous membrane is thin,
forms papillae, and is adherent to the muscles.
• On the Pharyngeal part of the dorsum, It is very rich in
lymphoid follicles.
• On the Inferior surface, It is thin and smooth. Numerous
glands, both mucous and serous lie deep to the mucous
membrane.
• Taste buds are most numerous on the sides of the Circumvallate
papillae, and on the walls of the surrounding sulci. Taste buds
are numerous over the foliate papillae and over the Posterior
1/3rd of the tongue; and sparsely distributed on the fungiform
papillae, Soft palate, Epiglottis and the pharynx. There are no
taste buds on the mid dorsal region of the oral part of the
tongue.
•

36.  Structure: There are two types of cells, The Sustentacular or
Supporting cells and Gustatory cells. The Supporting cells
are spindle shaped while Gustatory cells are long slender and
centrally situated.
Taste Pathway:
• Taste from Anterior 2/3rd of tongue except from Vallate
papillae is carried by Chorda tympani branch of facial till the
Geniculate ganglion. The central process go to the Tractus
solitarius in the medulla.
• Taste from Posterior 1/3rd of the tongue including the
Circumvallate papillae is carried by cranial nerve IX till the
Inferior ganglion. The central processes also reach the
Tractus solitarius.
• Taste from Posteriormost part of tongue and epiglottis
travels through Vagus nerve till the inferior ganglion of
Vagus. These central processes also reach Tractus solitarius.

37.  After relay in Tractus solitarius, 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 here take them to lowest part of
Postcentral gyrus, which is area for taste.