The lingual tonsils are rounded masses of lymphatic tissue that cover the posterior region of the tongue

Tongue

The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...

.

They are located on the dorsal surface at the base of the tongue. Their lymphatic tissue are dense and nodular, their surface is covered with stratified squamous epithelium

Stratified squamous epithelium

A stratified squamous epithelium consists of squamous epithelial cells arranged in layers upon a basement membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity...

 which invaginates as a single crypt

Crypt (anatomy)

Crypts are anatomical structures that are narrow but deep invaginations into a larger structure.One common type of anatomical crypt is the Crypts of Lieberkühn. However, it is not the only type: some types of tonsils also have crypts...

 into each lingual tonsil. They are partially surrounded by connective tissue placing them in the group of Partially-Encapsulated Lymphatic Organs, tonsils, the only one of its kind. They have associated mucous

Mucus

In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...

glands which are drained by ducts directly into the single tonsillar crypt.

External links

• Pictures at usc.edu (labeled as 'lymphoid tissue')]
• Diagram at healthopedia.com
• Diagram at enotes.com