1. By Dr. Sobia Ibrahim Assistant Professor Anatomy, KEMU
HISTOLOGY OF TONGUE
By Dr. Sobia Ibrahim
Assistant Professor Anatomy,
KEMU

2. Tongue is a muscular organ projecting into the oral cavity from its inferior side
Organ of speech
Organ of taste
It helps in swallowing
and plays a role in digestion

3. Three subdivisions
Root/base
Body
Tip

4. Muscles fibers firmly adherent to mucous membrane.
Tongue is basically a mass of striated muscle covered by mucous membrane
Lingual muscles are arranged in bundles that run in three planes; longitudinal, transverse, vertical
Muscles fibers firmly adherent to mucous membrane.
Between muscle fibers are gland
Mucous- at base
Serous- in body
Mixed- near tip

5. Dorsal is roughened bcz of papillae
It has two surfaces
Dorsal (superior)
Ventral (inferior)
Dorsal is roughened bcz of papillae
Ventral is smooth
Grossly dorsal surface is divided into anterior 2/3 and posterior 1/3 by sulcus terminalis

6. PAPILLAE
Mucosal irregularities and elevations in different forms and functions
Present anterior to sulcus terminalis on dorsum of tongue
These papillae and associated taste buds constitute the specialized mucosa of oral cavity
Filliform
Fungiform
Circumvallate
Foliate

7. Papillae of tongue

8. FILLIFORM PAPILLAE Smallest and most numerous in humans Conical
Heavily keratinized
Lacks taste buds
Distributed over entire anterior dorsal surface
Provides rough surface

9. FUNGIFORM PAPILLAE Less numerous Mushroom shaped Lightly keratinized
Covering epithelium thin
CT core with blood vessels
Taste buds on upper surface
Rich blood supply give its red color

10. Vallate (circumvallate) papillae
Least numerous
Largest in size
Abundance of taste buds
Size = 1-3 mm & number is 8- 12
Lie anterior to sulcus terminalis
Surrounded by groove
Ducts of deeply located serous glands (von Ebner’s) open into groove

11. FOLIATE PAPILLAE Poorly developed in humans
Forms furrows on posterolateral aspect of tongue
Contain taste buds

14. TASTE BUDS Receptors for taste sensation Oval, pale staining bodies
Extends through thickness of epith
A small opening on epithelial surface at the apex of taste bud is Taste pore
Sensations
Sweet & salt- tip
Sour- sides
Bitter - back

15. Consists of cells
Three principal cells
Neuroepithelial/ Gustatory cells having microvilli
Supportive cells
Stem cells
Rest on basal lamina
Gustatory cells supplied by sensory axon

16. POSTERIOR 1/3 Irregular, nodular surface
Lingual tonsil (Waldeyer’s ring)
Crypts