Tonsils are collections of lymphoid tissue located in the aerodigestive tract that form Waldeyer's ring and act as the immune system's first line of defense. Waldeyer's ring includes the adenoid tonsils, two tubal tonsils, two palatine tonsils, and the lingual tonsil. Tonsils contain specialized cells called M cells that capture pathogens and alert the immune system, stimulating B cells and T cells to respond. This leads to the production of antibodies and memory B cells in germinal centers within the tonsils. Tonsils can also become inflamed or infected, leading to tonsillitis, or develop calcified material known as tonsilloliths.

1. TONSILFirst 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
1. Adenoid tonsil
2. Two tubal tonsils
3. Two palatine tonsils
4. 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
• Immune 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.
o The main substance is
mostly calcium.
o Have a strong unpleasant odor
because of hydrogen sulfide and
methyl mercaptan and other
chemicals.

7. Thank You