Tongue Anatomy and Functions Quiz

The Tongue

• The tongue is a movable muscular organ with a root, body, and tip.
• It has a curved dorsal surface and an inferior ventral surface.
• The tongue plays a crucial role in mastication, swallowing, taste, speech, oral hygiene, and defense.

Structures of the Tongue

• The dorsum (top surface) of the tongue is divided into an anterior two-thirds (oral/body) and a posterior one-third (pharyngeal/base).
• These sections are separated by the sulcus terminalis, a triangle-shaped landmark.
• The foramen caecum is located at the apex of the sulcus terminalis.
• The ventral surface (underside) of the tongue is covered by a thin mucosa and contains structures like the lingual frenum and deep lingual veins.
• The lateral borders of the tongue feature ridges of foliate papillae.

Lingual Papillae

• Four types of lingual papillae are found on the dorsum of the tongue:
  • Filiform papillae – most numerous, responsible for texture sensation.
  • Fungiform papillae – mushroom-shaped, contain taste buds.
  • Circumvallate papillae – largest, arranged in a V-shape, contain taste buds.
  • Foliate papillae – located on the lateral borders, contain taste buds.

Taste buds

• Taste buds are barrel-shaped organs composed of 30-80 spindle-shaped cells extending from the basement membrane to the epithelial surface.
• They are found on fungiform, foliate, and circumvallate papillae.
• Taste bud cells have a rapid turnover rate of approximately 10 days.

Muscles of the Tongue

• Extrinsic muscles: Responsible for moving the tongue.
  • Hyoglossus: Depresses the tongue and assists in retraction.
  • Palatoglossus: Lifts the tongue, closing off the mouth from the pharynx during swallowing.
  • Styloglossus: Draws the tongue upwards and backwards.
• Intrinsic muscles: Alter the shape of the tongue.
  • Superior Longitudinal Muscle: Shortens the tongue and turns the tip and sides upwards.
  • Inferior Longitudinal Muscle: Shortens the tongue and pulls the tip and sides downwards.
  • Vertical Muscle: Flattens and broadens the tongue.
  • Transverse Muscle: Narrows and lengthens the tongue.

Nerve Innervation

• Sensory and Taste:
  • Posterior 1/3: Glossopharyngeal Nerve (IX)
  • Anterior 2/3:
    • Sensory: Lingual nerve (Trigeminal Nerve V)
    • Taste: Chorda Tympani (Facial nerve VII) & Lingual nerve
• Motor:
  • Hypoglossal nerve (XII), except for Palatoglossus, which is supplied by the Vagus nerve (X).

Blood Supply

• Arterial: Lingual artery (a branch of the external carotid artery).
• Venous: Lingual vein.

Variations in Tongue Appearance

• Geographic tongue: Benign condition characterized by smooth, irregular red patches and white wavy lines that may change position.
• Glossitis: Inflammation of the tongue, causing swelling, redness, and changes in surface texture. Can be caused by various factors, including anemia, celiac disease, trauma, and allergies.
• Black hairy tongue: Overgrowth of elongated papillae, often caused by smoking, antibiotics, and radiotherapy.
• Tongue piercings: Can impact oral hygiene and tooth integrity.
• Squamous cell carcinoma (SCC): Most common type of oropharyngeal cancer, frequently occurring on the tongue.

Additional Resources

• YouTube:
  • Development of the tongue
  • Muscles of the tongue (anatomy)
• Websites:
  • InformedHealth.org: How does the tongue work?
  • KenHub: Muscles and Taste Sensation of the Tongue
  • KenHub: Tongue

Test your knowledge on the anatomy and functions of the tongue. This quiz covers the structures, types of papillae, and the role of the tongue in various processes such as taste and speech. Perfect for students of anatomy and health sciences.