Tonsil
- For the structure in the cerebellum, see cerebellar tonsil.
The human palatine tonsils and the nasopharyngeal tonsil are lymphoepithelial tissues located in strategic areas of the oropharynx and nasopharynx, although most commonly - the term "tonsils" refers to the palatine tonsils [that can be seen in the back of the throat]. These immunocompetent tissues represent the defense mechanism of first line against ingested or inhaled foreign pathogens. However, the fundamental immunological roles of tonsils have yet to be addressed. [1][2]
Like other organs of the lymphatic system, some believe them to be involved in helping fight off pharyngeal and upper respiratory tract infections, but there is no conclusive evidence to that effect.
An inflammation of the tonsils is called tonsillitis. [3]
Contents |
Types
Tonsils in humans include, from anterior (front),superior (top), posterior (back), and inferior (bottom):
| Type | Epithelium | Capsule | Crypts | Location |
|---|---|---|---|---|
| Adenoids (also termed "pharyngeal tonsils") | Ciliated pseudostratified columnar (respiratory epithelium) | Incompletely encapsulated | No | Roof of pharynx |
| Tubal tonsils | Ciliated pseudostratified columnar (respiratory epithelium) | Roof of pharynx | ||
| Palatine tonsils | Non-keratinized stratified squamous | Incompletely encapsulated | Long, branched[4] | Sides of oropharynx between palatoglossal and palatopharyngeal arches |
| Lingual tonsils | Non-keratinized stratified squamous | Incompletely encapsulated | Long, unbranched[5] | Behind terminal sulcus (tongue) |
Together this set of lymphatic tissue is known as Waldeyer's tonsillar ring.
Growth
Tonsils tend to reach their largest size near puberty, and they gradually undergo atrophy thereafter. However, they are largest relative to the diameter of the throat in young children.
Tonsils can become enlarged or inflamed (tonsillitis) and may be surgically removed in tonsillectomy. This may be indicated if they obstruct the airway or interfere with swallowing. 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.
Some doctors who are not ear, nose and throat (ENT) specialists are conservative on recommending the removal of tonsils, because the tissue cannot be put back, and some claim that removal decreases the power of the immune system. ENT specialists generally recommend removal if there are frequent recurrent tonsillitis, adenotonsillar hyperplasia causing symptomatic partial upper airway obstruction or asymmetry.
Tonsil enlargement can affect speech, making it hypernasal and giving it the sound of velopharyngeal incompetence.[6]
Tonsilloliths
A tonsillolith is material that accumulates on the tonsil. They can range up to the size of a peppercorn and are white/cream color. The main substance is mostly collagen, but they have a strong unpleasant odor because of hydrogen sulfide and methyl mercaptan and other substances.
References
- ↑ Journal of the Wakayama Medical Society - [Study on functions of tonsils in mucosal immune system of the upper respiratory tract using a novel animal model, Suncus murinus.] - VOL.52;NO.4;PAGE.361-367(2001)
- ↑ 'Tonsils and adenoids are immune system glands...' [Harvard Medical School Family Health Guide - Page: 1006 ] - 1995
- ↑ Udayan K Shah, MD, Associate Professor of Otolaryngology-Head and Neck Surgery, Jefferson Medical College, Thomas Jefferson University; Director, Fellow and Resident Education in Pediatric Otolaryngology, Attending Surgeon, Division of Otolaryngology, Nemours-AI duPont Hospital for Children
- ↑ http://ect.downstate.edu/courseware/histomanual/lymphatic.html
- ↑ http://ect.downstate.edu/courseware/histomanual/lymphatic.html
- ↑ Mora R, Jankowska B, Mora F, Crippa B, Dellepiane M, Salami A. (2009). Effects of tonsillectomy on speech and voice. J Voice. 23(5):614-8. doi:10.1016/j.jvoice.2008.01.008 PMID 18468843
External links
|
|||||||||||||||||||||||||||||||||