Tongue (Anatomy & Physiology)

The Basic Anatomy & Physiology of Tongue is explained in simplified manner for proper understanding.

1. Tongue (Anatomy & Physiology) Mr. Vikrant Udutha NK Jabshetty Ayurvedic Medical College& PG Centre Final Year Student

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. 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.

9. Papillae Of Tongue

10. 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.

11. 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. Sup . Longitudinal – Shortens the tongue & makes dorsum concave Inf . Longitudinal – Shortens the tongue makes its convex Transverse – Makes the tongue narrow & elongated Vertical – Makes tongue broad & flattened Extrinsic – It contains 4 muscles which connect the tongue to mandible , to hyoid bone, to styloid process & to palate. Genioglossus – Protrudes the tongue Hyoglossus – Depresses the Tongue Styloglossus – Retracts the Tongue Palatoglossus – Elevates the Tongue

12. Muscles of Tongue

13. 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

14. 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.

15. 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

16. 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 Type 1 cells Type 2 cells Type 3 cells 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

17. Pathway for Taste

18. 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.

19. Taste Discrimination

20. Queries?

21. * धन्यवाद *