2. Topics
• Introduction
• Parts of Tongue
• Papillae of Tongue
• Muscles of Tongue
• Blood Supply of Tongue
• Nerve Supply
• Lymphatic Drainage
• Normal Physiology
3. Tongue is one among the five sensory
organ.
It is the muscular organ situated in the
floor of the mouth.
It is associated with the functions of
Taste, Speech, Chewing & Deglutition
Tongue comprises of skeletal muscle
which is voluntary in function.
Introduction
4. Parts of Tongue
• Root
• Tip
• Body
1) Dorsum
a) Oral Part
b) Pharyngeal Part
c) Posterior Part
2) Inferior Surface
5. Root of Tongue
Attached to –
a) Above - Styloid Process & Soft Palate
b) Below – Mandible & Hyoid Bone
In between the mandible and hyoid bones, it is related to the Geniohyoid and
Mylohyoid muscles
Tip of Tongue
It forms the anterior free end which at rest lies behind the Upper Incisor Teeth
6. Dorsum of Tongue
It is convex in all the directions & divided by a faint V-shaped groove called as Sulcus Terminale.
• Oral Part or Papillary Part:
It is placed on the floor of the mouth.
The margins are free & in contact with gums and teeth
Each margin shows a 4-5 vertical folds called as Foliate Papillae
Surfaces-
a)Superior- Has a median furrow & covered with papillae
b) Inferior- Covered with smooth mucous membrane which shows a median fold called Frenulum
Linguae.
On either side of Frenulum, there is prominence made by Deep Lingulal Veins
It also has a folds called Plica Fimbriata which is directed forwards and medially towards Tip of
Tongue.
7. • Pharyngeal Part or Lymphoid Part -
It lies behind the palatoglossal arches and the sulcus terminalis.
Its mucous membrane has no papilae but has many Lymphoid follicles which
collectively forms Lingual Tonsil.
Its posterior surface called as Base Of Tongue & forms anterior wall of
Oropharynx.
• Posterior Part-
It is connected to epiglottis by 3 folds of mucous membrane, they are Right,
Median & Left Glossoepiglottic Folds.
On either side of median fold there is depression called as Vallecula.
8.
9. Papillae of Tongue
Papillae are the projections of mucous membrane (corium) which gives the roughness. These are of 3
types-
1) Circumvallate or Vallate Papillae:
They are large in size about 1-2 mm in diameter & are totally 8-12 in number.
Situated exactly in front of sulcus terminalis
Each papillae is a cylindrical projection surrounded by a circular sulcus. The walls of this papillae have
Taste Buds.
2) Fungiform Papillae:
These are numerous and mostly present near the tip & margins of Tongue. Some are also
scattered over Dorsum.
Smaller than Circumvallate Papillae, but larger than Filiform Papillae.
Each papilla ha narrow pedicle and large rounded head.
They are distinguished by their bright red color.
11. 3) Filiform Papillae or Conical Papillae:
It covers the presulcal area of dorsum and gives characteristic
Velvety appearance.
These are smallest and numerous.
Each papilla is pointed and covered with keratin & apex is often spilt into
filamentous processes.
12. Muscles of Tongue
The Middle Fibrous septum divides the tongue into right and left halves.
Each half contains:-
Intrinsic – It contains 4 muscles which occupy the upper part & attached to submucous fibrous layer.
They alter the shape of the tongue.
1) Sup. Longitudinal – Shortens the tongue & makes dorsum concave
2) Inf. Longitudinal – Shortens the tongue makes its convex
3) Transverse – Makes the tongue narrow & elongated
4) Vertical – Makes tongue broad & flattened
Extrinsic – It contains 4 muscles which connect the tongue to mandible , to hyoid bone, to styloid process & to palate.
1) Genioglossus – Protrudes the tongue
2) Hyoglossus – Depresses the Tongue
3) Styloglossus – Retracts the Tongue
4) Palatoglossus – Elevates the Tongue
14. Blood Supply:
Arterial Supply:
1) Lingual Artery - Branch of Ext. Carotid Artery
2) Tonsillar Artery – Branch of Facial Artery
3) Pharyngeal Branch of Ext. Carotid Artery
Venous Drainage:
- Deep Lingual Vein
15. Lymphatic Drainage:
• Tip of Tongue – Submental Nodes
• Rt & Lt halves – Submandiblar Nodes
• Posterior part- Upper Deep Cervical Nodes
The whole lymph finally drains into jugulo-omohyoid nodes.
16. Nerve Supply:
• Motor Nerves-
All Intrinsic & Extrinsic Muscles supplied by Hypoglossal Nerve, except
Palatoglossus.
Palatoglossus is supplied by cranial root of Accessory Nerve.
• Sensory Nerves-
Lingual Nerve & Chorda Tympani - Taste of Anterior Two-Third
Glossopharyngeal Nerve - Taste of Posterior One – Third
Vagus Nerve – Taste of Posterior Part
17. Sensation of Taste
• Structure of Taste Buds
Each Taste Bud is a bundle of receptor cells.
It contains about 40 cells which are the modified epithelial cells
Cells are divided into 4 groups
1) Type 1 cells
2) Type 2 cells
3) Type 3 cells
4) Type 4 cells
Type 1, 2, 3 have microvilli which project into an opening in epithelium covering the
tongue. This opening is called as Taste Pore
20. Types of Taste
• Sweet Taste- Produced by Organic Substances like Monosaccharides,
Polysaccharides, Glycerol, Aldehydes, Ketones.
• Salt Taste- Produced by Chlorides and Nitrates of Na, K & Ammonia.
• Sour Taste- Produced because of Hydrogen ions.
• Bitter Taste- Produced due to organic substances like Strychnine,
Morphine, Piric Acid, Bile Salts, Salts of Ca, Mg & Ammonium.
• Umami- Produced due to Glutamate, particularly Monosodium
Glutamate.