Tonsil

Tonsils are the first line of defense against ingested aero-digestive foreign pathogens.

1. TONSIL First Line Of Defense Against Ingested Or Inhaled Foreign Pathogens.

2. What is Tonsil ? Tonsils  are collections of  lymphoid  tissue  facing into the aerodigestive tract. 

3. Waldeyer’s Ring   Waldeyer's tonsillar ring includes Adenoid tonsil Two tubal tonsils Two palatine tonsils Lingual tonsil.

4. Type Epithelium capsule Crypts Location Adenoids Ciliated pseudostratified columnar Incompletely encapsulated No crypts, but small folds Roof of  pharynx Tubal tonsils Ciliated pseudostratified columnar Roof of pharynx Palatine tonsils Non-keratinized stratified squamous Incompletely encapsulated Long, branched Sides of  oropharynx between palatoglossal and palatopharyngeal arches Lingual tonsils Non-keratinized stratified squamous Incompletely encapsulated Long, branched Behind  terminal sulcus (tongue)

5. Functions I mmune system's first line of defense against ingested or inhaled foreign pathogens . Tonsils have on their surface specialized antigen capture cells called M cells that allow for the uptake of antigens produced by pathogens. These M cells then alert the underlying B cells and T cells in the tonsil that a pathogen is present and an immune response is stimulated.  B cells are activated and proliferate in areas called germinal centres in the tonsil. These germinal centres are places where B memory cells are created and secretory antibody ( IgA ) is produced. Tonsils produce T lymphocytes, also known as T-cells, in a manner similar to, but different from, the way the thymus does .

6. Clinical Tonsilitis : Tonsils can become enlarged or inflamed. Tonsillolith :   It is material that accumulates on the tonsil. They can range up to the size of a peppercorn and are white/cream in color. The main substance is mostly  calcium . H ave a strong unpleasant odor because of hydrogen sulfide and methyl  mercaptan  and other chemicals.

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