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1. either of two small masses of lymphatic tissue situated one on each side of the back of the mouth
2. Anatomy any small rounded mass of tissue, esp lymphatic tissue
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


Localized aggregation of diffuse and nodular lymphoid tissue found in the region where the nasal and oral cavities open into the pharynx. The tonsils are important sources of blood lymphocytes. They often become inflamed and enlarged, necessitating surgical removal.

The two palatine (faucial) tonsils are almond-shaped bodies measuring 1 by 0.5 in. (2.5 by 1.2 cm) and are embedded between folds of tissue connecting the pharynx and posterior part of the tongue with the soft palate. These are the structures commonly known as the tonsils. The lingual tonsil occupies the posterior part of the tongue surface. It is really a collection of 35–100 separate tonsillar units, each having a single crypt surrounded by lymphoid tissue. Each tonsil forms a smooth swelling about 0.08– 0.16 in. (2–4 mm) in diameter. The pharyngeal tonsil (called adenoids when enlarged) occupies the roof of the nasal part of the pharynx. This tonsil may enlarge to block the nasal passage, forcing mouth breathing. See Lymphatic system

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.


Localized aggregation of diffuse and nodular lymphoid tissue found in the throat where the nasal and oral cavities open into the pharynx.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
While squamous cell carcinomas of the tonsils show unilateral growth and mucosal ulceration, lymphomas demonstrate normal mucosal appearance with asymmetrically growth of the tonsil (9).
For decades, millions of children across the world have undergone surgery to remove their tonsils and adenoids.
So identification and isolation of bacteria from the core of tonsil tissue is important for many reasons.
'We calculated disease risks depending on whether adenoids, tonsils or both were removed in the first 9 years of life because this is when these tissues are most active in the developing immune system,' said one of the study authors, Sean Byars from University of Melbourne in Australia.
Those latter two cancer types can frequently be traced to the pockets within the tonsils. The researchers may have found the culprit that is harboring them: the "thin, slimy sheets of bacteria" known as biofilms, according to a statement from the ( University of Rochester.
[U.S.A], Feb.1 (ANI): It has come to light that cancer causing virus may hide in small pockets on the surface of tonsils in throats of unsuspected people.
Baranak, "Bacteriology of tonsil surface and core in children," The Laryngoscope, vol.
For one such patient described in this case report, we theorize a phenomenon that allows for hypertrophied tonsils to be nonobstructive, as the tonsils could instead splint or stent the airway open.
We described the case of a six-month-old infant presenting with acute onset respiratory distress due to a fast growing (or more likely congenital origin) hamartoma arising from the palatine tonsil. It is important to perform a thorough examination of the respiratory system, including a local examination of the oral cavity in any patient presenting with respiratory distress.
Sometimes the tonsils can also become very large and cause a narrowing of the airways which can cause breathing difficulties, resulting in snoring and/or "raspy" breathing sounds.
u In case of peritonsillar abscess, where the tonsil infection has become so bad that it spreads and pus collects around the tonsil.