The lingual tonsils are a collection of lymphoid tissue located in the lamina propria of the root of the

tongue The tongue is a Muscle, muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper s ...

. This lymphoid tissue consists of the nodules rich in cells of the

immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

( immunocytes). The immunocytes initiate the immune response when the lingual tonsils get in contact with invading

microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...

s (

pathogenic In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ...

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

Structure

Microanatomy

Lingual tonsils are covered externally by

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

(nonkeratinized) that invaginates inward forming tonsillar crypts. Beneath the epithelium is a layer of lymphoid nodules containing lymphocytes. Mucous glands located at the root of the tongue are drained through several ducts into the crypts of the lingual tonsils. Secretions of these mucous glands keep the crypts clean and free of any debris.

Blood supply

Lingual tonsils are located on posterior aspect of tongue which is supplied through: * Lingual artery, branch of

external carotid artery The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland. Structure Origin T ...

* Tonsillar artery *Ascending and descending palatine arteries * Ascending pharyngeal branch of external carotid artery

Nerve supply

Lingual tonsils are innervated by tonsillar nerves from the tonsilar plexus, formed by the glossopharyngeal and vagus nerves.

Function

Like other lymphatic tissues, the function of lingual tonsils is to prevent infections. These tonsils contain B and T lymphocytes which get activated when harmful bacteria and viruses come in contact with tonsils. B lymphocytes kill pathogens by producing antibodies against them, while T lymphocytes directly kill them releasing cytotoxic substances or indirectly by stimulating other cells of the immune system.

Clinical significance

Cancer

Squamous cell carcinoma Squamous-cell carcinoma (SCC), also known as epidermoid carcinoma, comprises a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the ...

is a type of neoplasm that can affect lingual tonsils.

Sleep apnea

Enlarged or hypertrophic lingual tonsils have the potential to cause or exacerbate sleep apnea.

Additional images

File:Slide1sss.JPG, Lingual tonsil File:Slide7ttt.JPG, Lingual tonsil File:Slide12uuu.JPG, Lingual tonsils

References

External links

Pictures at usc.edu
* * * (labeled as 'lymphoid tissue')]
Lingual Tonsil
{{Authority control Lymphatics of the head and neck Tongue Tonsil