Adenoid

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Adenoid
Location of the adenoid
MeSH Adenoids
Dorlands/Elsevier t_13/12812454

Adenoids (or pharyngeal tonsils, or nasopharyngeal tonsils) are a mass of lymphoid tissue situated at the very back of the nose, in the roof of the nasopharynx, where the nose blends into the mouth.

Normally, in children, they make a soft mound in the roof and posterior wall of the nasopharynx, just above and behind the uvula.

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[edit] Function

Adenoids are part of the immune system. Like all lymphoid tissue, they trap infectious agents like viruses and bacteria, and they produce antibodies.

Since the adenoids are located at the back of the nasal airway, they provide defense against inhaled substances.

This function decreases with age as the adenoids shrink. Because adenoids do ordinarily shrink by late childhood, the problems caused by enlarged adenoids rarely occur in adults.

[edit] Pathology

Enlarged adenoids, or adenoid hypertrophy, can become nearly the size of a ping pong ball and completely block airflow through the nasal passages.

Even if enlarged adenoids are not substantial enough to physically block the back of the nose, they can obstruct airflow enough so that breathing through the nose requires an uncomfortable amount of work, and inhalation occurs instead through an open mouth.

Adenoids can also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether.

[edit] Removal of the adenoids

Surgical removal of the adenoids is a procedure called adenoidectomy.

Carried out through the mouth under a general anaesthetic, adenoidectomy involves the adenoids being curetted, cauterised, lasered, or otherwise ablated.

[edit] Histology

Adenoids, unlike other types of tonsils, have pseudostratified columnar epithelium.[1]

They also differ from the other tonsil types by lacking crypts.

[edit] Cultural significance

[edit] See also

[edit] References

  1. ^ Histology at KUMC lymphoid-lymph06

[edit] External links

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Lymphatic system
Bone marrow | Thymus (Hassall's corpuscles) | Spleen (White pulp, Periarteriolar lymphoid sheaths, Marginal zone, Red pulp) | Tonsils (Palatine, Lingual, Adenoid)

Mucosa-associated lymphoid tissue: Gut-associated lymphoid tissue | Peyer's patches

Lymph nodes: Subcapsular sinus | Paracortex | head and neck (Cervical, Virchow's) | iliac (External, Common, Internal) | lumbar/paraaortic (Lateral aortic, Preaortic, Inferior mesenteric, Retroaortic) | inguinal (Deep, Superficial) | Axillary

Lymph vessels: Thoracic duct | Right lymphatic duct | Cisterna chyli  | Lumbar trunk | Intestinal trunk

Lymph | Lymphocytes | High endothelial venules | Immune system