Tongue

Tongue

1. Introduction
   • The tongue is a muscular organ in the oral cavity responsible for taste, speech, chewing, and swallowing.
   • It is covered by a moist mucous membrane and has a rough surface due to papillae.
2. Structure of the Tongue
   A. Parts of the Tongue
   • Apex (tip): most anterior and highly mobile part.
   • Body: the main central part with a rough dorsal surface containing papillae.
   • Root (base): posterior third; attached to the floor of the mouth and contains lymphoid tissue (lingual tonsils).
   B. Surfaces
   • Dorsal (top) surface: rough due to papillae that contain taste buds.
   • Ventral (under) surface: smooth, attached to the floor of the mouth by the lingual frenulum.
3. Muscles of the Tongue
   A. Intrinsic Muscles
   • Located entirely within the tongue; change its shape and size for speech and swallowing.
   • Include superior longitudinal, inferior longitudinal, transverse, and vertical muscles.
   B. Extrinsic Muscles
   • Originate outside the tongue and insert into it; move the tongue in different directions.
   • Include genioglossus, hyoglossus, styloglossus, and palatoglossus.
4. Functions of the Tongue
   • Taste: taste buds on papillae detect five basic tastes — sweet, sour, salty, bitter, and umami.
   • Speech: helps articulate sounds by changing shape.
   • Mastication: moves and mixes food during chewing.
   • Swallowing (deglutition): pushes food backward into the pharynx.
   • Oral cleansing: aids in cleaning teeth and oral cavity.
5. Blood Supply and Nerve Innervation
   • Blood supplied mainly by the lingual artery.
   • Motor control by hypoglossal nerve (cranial nerve XII).
   • Sensory branches: anterior two-thirds by the lingual nerve (trigeminal nerve V3) for general senses and chorda tympani (facial nerve VII) for taste.
   • Posterior one-third supplied by glossopharyngeal nerve (cranial nerve IX) for both taste and sensation.
6. Common Disorders
   • Glossitis: inflammation causing swelling and pain.
   • Burns or trauma: affect taste and mobility.
   • Fissured tongue: deep grooves on the tongue surface.
   • Cancer of the tongue: usually at the lateral borders, requiring early detection.
   • Ankyloglossia (tongue-tie): limited tongue movement due to short frenulum.
7. Nursing Considerations
   • Inspect the tongue for color, moisture, lesions, and swelling.
   • Encourage oral hygiene practices to prevent infections.
   • Monitor swallowing ability and speech in neurological or trauma patients.
   • Educate patients about nutrition and hydration for healthy tongue tissue.
   • Assist in care for patients with tongue surgery or cancers.
8. Summary for Quick Review
   The tongue is a muscular organ with intrinsic and extrinsic muscles allowing shape changes and movements important for taste, speech, chewing, and swallowing. It has a dorsal surface with papillae and taste buds, and is innervated by several cranial nerves for motor, sensory, and taste functions. Nursing care includes assessment, promoting oral hygiene, and monitoring for disorders.