A brief knowledge on anatomy & physiology of Tonsils

1. ANATOMY AND
PHYSIOLOGY TONSILS
MRS. Priya Gerard

2. TONSILS
 The tonsils are a set of lymphoid organs facing
into the aerodigestive tract, which is known
as Waldeyer's tonsillar ring and consists of
the adenoid tonsil, two tubal tonsils, two palatine
tonsils, and the lingual tonsils. These organs play
an important role in the immune system.
 When used unqualified, the term most commonly
refers specifically to the palatine tonsils, which are
two lymphoid organs situated at either side of the
back of the human throat. The palatine tonsils and
the adenoid tonsil are organs consisting of
lymphoepithelial tissue located near
the oropharynx and nasopharynx (parts of the
throat).

4. Humans are born with four types of tonsils: the pharyngeal tonsil, two tubal tonsils, two
palatine tonsils and the lingual tonsils.
Type Epithelium capsule Crypts Location
Adenoid (also
termed
"pharyngeal
tonsil")
Ciliated
pseudostratified
columnar (respiratory
epithelium)
Incompletely
encapsulated
No crypts,
but small
folds
Roof
of pharynx
Tubal tonsils
Ciliated
pseudostratified
columnar (respiratory
epithelium)
Roof of
pharynx
Palatine tonsils
Non-keratinized
stratified squamous
Incompletely
encapsulated
Long,
branched[2]
Sides
of oropharynx
between
palatoglossal
and
palatopharyn
geal arches
Lingual tonsils
Non-keratinized Incompletely Long,
Behind termin
al sulcus

5. DEVELOPMENT OF TONSILS
 The palatine tonsils tend to reach their largest
size in puberty, and they gradually
undergo atrophy thereafter. However, they are
largest relative to the diameter of the throat in
young children. In adults, each palatine tonsil
normally measures up to 2.5 cm in length,
2.0 cm in width and 1.2 cm in thickness.
 The adenoid grows until the age of 5, starts to
shrink at the age of 7 and becomes very small
in adulthood.

6. Function
 The tonsils are immunocompetent organs which serve
as the immune system's first line of defense against
ingested or inhaled foreign pathogens, and as such
frequently engorge with blood to assist in immune
responses to common illnesses such as the common
cold. The 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 centers in the
tonsil. These germinal centres are places where B
memory cells are created and secretory antibody
(IgA) is produced.

7. CLINICAL SIGNIFICANCE
 The palatine tonsils can become enlarged
(adenotonsillar hyperplasia) or inflamed
(tonsillitis). The most common way to treat
tonsillitis is with anti-inflammatory drugs such
as ibuprofen, or if bacterial in
origin, antibiotics,
e.g. amoxicillin and azithromycin.
 Surgical removal (tonsillectomy) may be
advised if the tonsils obstruct the airway or
interfere with swallowing, or in patients with
severe or recurrent tonsillitis.

8. Contd….
 However, different mechanisms of
pathogenesis for these two subtypes of
tonsillar hypertrophy have been
described, and may have different responses
to identical therapeutic efforts. In older
patients, asymmetric tonsils (also known as
asymmetric tonsil hypertrophy) may be an
indicator of virally infected tonsils, or tumors
such as lymphoma or squamous cell
carcinoma.

9. Contd….
 A tonsillolith (also known as a “tonsil stone”) is
material that accumulates on the palatine
tonsil. This can reach the size of
a peppercorn and is white or cream in color.
 The main substance is mostly calcium, but it
has a strong unpleasant odor because
of hydrogen sulfide and methyl mercaptan and
other chemicals.

10. Contd….
 Palatine tonsil enlargement can affect speech,
making it hypernasal and giving it the sound
of velopharyngeal incompetence (when space
in the mouth is not fully separated from the
nose's air space).
 Tonsil size may have a more significant
impact on upper airway obstruction for obese
children than for those of average weight.

11. Contd….
 As mucosal lymphatic tissue of
the aerodigestive tract, the palatine tonsils are
viewed in some classifications as belonging to
both the gut-associated lymphoid
tissue (GALT) and the mucosa-associated
lymphoid tissue (MALT).
 Other viewpoints treat them (and
the spleen and thymus) as large lymphatic
organs contradistinguished from the smaller
tissue loci of GALT and MALT.