Palatine tonsil

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Palatine tonsil
Tonsillary branches of lesser palatine nerves
Identifiers
Latintonsilla palatina
MeSHD014066
TA98A05.2.01.011
TA22853, 5181
FMA9610
Anatomical terminology]

Palatine tonsils, commonly called the tonsils and occasionally called the faucial tonsils,

tonsils located on the left and right sides at the back of the throat
, which can often be seen as flesh-colored, pinkish lumps. Tonsils only present as "white lumps" if they are inflamed or infected with symptoms of exudates (pus drainage) and severe swelling.

chronic cases, tonsillectomy may be indicated.[4]

Structure

The palatine tonsils are located in the

.

The palatine tonsil is one of the

lingual tonsils.[7] From the pharyngeal side, they are covered with a stratified squamous epithelium
, whereas a fibrous capsule links them to the wall of the pharynx. Through the capsule pass trabecules that contain small blood vessels, nerves and lymphatic vessels. These trabecules divide the tonsil into lobules.

Blood supply and innervation

The nerves supplying the palatine tonsils come from the maxillary division of the trigeminal nerve via the lesser palatine nerves, and from the tonsillar branches of the glossopharyngeal nerve. The glossopharyngeal nerve continues past the palatine tonsil and innervates the posterior 1/3 of the tongue to provide general and taste sensation.[7] This nerve is most likely to be damaged during a tonsillectomy, which leads to reduced or lost general sensation and taste sensation to the posterior third of the tongue.[8][9]

Blood supply is provided by tonsillar branches of five arteries: the

lesser palatine artery (a branch of the descending palatine artery, itself a branch of the maxillary artery
). The tonsils venous drainage is by the peritonsillar plexus, which drain into the lingual and pharyngeal veins, which in turn drain into the internal jugular vein.[7]

Tonsillar crypts

lymphoid tissue. Many lymph cells (dark-colored region) pass from the nodules toward the surface and will eventually mix with the saliva
as salivary corpuscles (s).

Palatine tonsils consist of approximately 15 crypts, which result in a large internal surface. The tonsils contain four lymphoid compartments that influence immune functions, namely the reticular crypt

lymphoid follicles, and the follicular germinal centers. In human palatine tonsils, the very first part exposed to the outside environment is tonsillar epithelium.[10]

Function

Local immunity

Tonsillar (relating to palatine tonsil) B cells can mature to produce all the five major

Immunoglobulin A
produced by tonsillar B cells in vitro appears to be 7S monomers, although a significant proportion may be l0S dimeric IgA.

In addition to humoral immunity elicited by tonsillar and

peripheral blood
.

Cytokine action

autoimmune, or malignant diseases appears to be influenced by the overall balance of production (profiles) of pro-inflammatory and anti-inflammatory cytokines. Therefore, determination of cytokine profiles in tonsil study will provide key information for further in-depth analysis of the cause and underlying mechanisms of these disorders, as well as the role and possible interactions between the T- and B-lymphocytes and other immunocompetent cells.[11]

The cytokine network represents a very sophisticated and versatile regulatory system that is essential to the immune system for overcoming the various defense strategies of microorganisms. Through several studies, the

microbial
antigens even when the subject is asymptomatic of ongoing infection. It could also be an effect of ontogeny of the immune system.

Clinical significance

The pathogenesis of infectious/inflammatory disease in the tonsils most likely has its basis in their anatomic location and their inherent function as organ of immunity, processing infectious material, and other antigens and then becoming, paradoxically, a focus of infection/inflammation. No single theory of pathogenesis has yet been accepted, however. Viral infection with secondary bacterial invasion may be one mechanism of the initiation of chronic disease,[12] but the effects of the environment, host factors, the widespread use of antibiotics, ecological considerations, and diet all may play a role.[13] A recent cross-sectional study revealed a high rate of prevalent virus infections in non-acutely ill patients undergoing routine tonsillectomy. However, none of the 27 detected viruses showed positive association to the tonsillar disease.[14]

In children, the tonsils are common sites of infections that may give rise to acute or chronic tonsillitis. However, it is still an open question whether tonsillar hypertrophy is also caused by a persistent infection. Tonsillectomy is one of the most common major operations performed on children. The indications for the operation have been complicated by the controversy over the benefits of removing a chronically infected tissue and the possible harm caused by eliminating an important immune inductive tissue.[15][16]

The information that is necessary to make a rational decision to resolve this controversy can be obtained by understanding the immunological potential of the normal palatine tonsils and comparing these functions with the changes that occur in the chronically diseased counterparts.

Acute tonsillitis

A medical animation still that shows Tonsillitis.
A medical animation still that shows tonsillitis.

Tonsillitis is the inflammation of tonsils. Acute tonsillitis is the most common manifestation of tonsillar disease. It is associated with sore throat, fever and difficulty swallowing.[17] The tonsils may appear normal sized or enlarged but are usually erythematous. Often, but not always, exudates can be seen. Not all these signs and symptoms are present in every patient.

Recurrent tonsillitis

Recurrent infection has been variably defined as from four to seven episodes of acute tonsillitis in one year, five episodes for two consecutive years or three episodes per year for 3 consecutive years.[18][19]

Tonsillar hypertrophy

Tonsillar hypertrophy is the enlargement of the tonsils, but without the history of inflammation. Obstructive tonsillar hypertrophy is currently the most common reason for tonsillectomy.[15] These patients present with varying degrees of disturbed sleep which may include symptoms of loud snoring, irregular breathing, nocturnal choking and coughing, frequent awakenings, sleep apnea, dysphagia and/or daytime hypersomnolence. These may lead to behavioral/mood changes in patients and facilitate the need for a polysomnography in order to determine the degree to which these symptoms are disrupting their sleep.[20][21]

Additional images

  • Lymphatic system
    Lymphatic system
  • The mouth cavity. The cheeks have been slit transversely and the tongue pulled forward.
    The mouth cavity. The cheeks have been slit transversely and the tongue pulled forward.
  • Throat after tonsillectomy
    Throat after tonsillectomy
  • Anterior photograph of the oral cavity showing palatine tonsils (inflamed) and uvula.
    Anterior photograph of the oral cavity showing palatine tonsils (inflamed) and
    uvula
    .
  • Open mouth with no visible palatine tonsils.
    Open mouth with no visible palatine tonsils.
  • Palatine tonsil
    Palatine tonsil

References

External links