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Tonsils diagram.jpg
Blausen 0861 Tonsils&Throat Anatomy2.png
Sagittal view of tonsils and throat anatomy
System Immune system Lymphatic system
Latin tonsilla, tonsillae (pl.)
TA98 A05.2.01.011
FMA 9609
Anatomical terminology

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 (or pharyngeal 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).


Humans are born with four types of tonsils: the pharyngeal tonsil, two tubal tonsils, two palatine tonsils and the lingual tonsils. [1]

Type Epithelium Capsule Crypts Location
Pharyngeal tonsil (also termed "adenoid") Ciliated pseudostratified columnar (respiratory epithelium)Incompletely encapsulatedSmall folds—sometimes described as crypts [2] Roof of pharynx
Tubal tonsils Ciliated pseudostratified columnar (respiratory epithelium)Roof of pharynx
Palatine tonsils Non-keratinized stratified squamous Incompletely encapsulatedLong, branched [3] Sides of oropharynx between palatoglossal
and palatopharyngeal arches
Lingual tonsils Non-keratinized stratified squamousIncompletely encapsulatedLong, unbranched [3] [4] Behind terminal sulcus (tongue)


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. [5]

The adenoid grows until the age of 5, starts to shrink at the age of 7 and becomes small in adulthood.[ medical citation needed ]


The tonsils are immunocompetent organs that 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 microfold cells (M cells) that allow for the uptake of antigens produced by pathogens. These M cells then alert the B cells and T cells in the tonsil that a pathogen is present and an immune response is stimulated. [6] B cells are activated and proliferate in areas called germinal centers in the tonsil. These germinal centers are places where B memory cells are created and secretory antibody (IgA) is produced.

Clinical significance

Gross pathology of fresh hypertrophic tonsil. Top left: Surface facing the into the aerodigestive tract. Top right: Opposite surface (cauterized). Bottom: Cut sections. Gross pathology of tonsil.jpg
Gross pathology of fresh hypertrophic tonsil. Top left: Surface facing the into the aerodigestive tract. Top right: Opposite surface (cauterized). Bottom: Cut sections.

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. [7] However, different mechanisms of pathogenesis for these two subtypes of tonsillar hypertrophy have been described, [8] 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.

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. [9]

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). [10] Tonsil size may have a more significant impact on upper airway obstruction for obese children than for those of average weight. [11]

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.

Additional images

Related Research Articles

<span class="mw-page-title-main">Thymus</span> Endocrine gland

The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule.

<span class="mw-page-title-main">Lymphatic system</span> Organ system in vertebrates complementary to the circulatory system

The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphoid organs, lymphoid tissues and lymph. Lymph is a clear fluid carried by the lymphatic vessels back to the heart for re-circulation. The Latin word for lymph, lympha, refers to the deity of fresh water, "Lympha".

<span class="mw-page-title-main">Lymph node</span> Organ of the lymphatic system

A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function.

<span class="mw-page-title-main">Palatine tonsil</span> Lymphoid organs at the back of the throat on both sides

Palatine tonsils, commonly called the tonsils and occasionally called the faucial tonsils, are 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 and severe swelling.

<span class="mw-page-title-main">Tonsillectomy</span> Surgical removal of the tonsils

Tonsillectomy is a surgical procedure in which both palatine tonsils are fully removed from the back of the throat. The procedure is mainly performed for recurrent tonsillitis, throat infections and obstructive sleep apnea (OSA). For those with frequent throat infections, surgery results in 0.6 fewer sore throats in the following year, but there is no evidence of long term benefits. In children with OSA, it results in improved quality of life.

<span class="mw-page-title-main">Adenoid</span> Type of tonsil

In anatomy, the pharyngeal tonsil, also known as the nasopharyngeal tonsil or adenoid, is the superior-most of the tonsils. It is a mass of lymphatic tissue located behind the nasal cavity, in the roof of the nasopharynx, where the nose blends into the throat. In children, it normally forms a soft mound in the roof and back wall of the nasopharynx, just above and behind the uvula.

<span class="mw-page-title-main">Tonsillitis</span> Inflammation of the tonsils

Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and enlarged lymph nodes around the neck. Complications include peritonsillar abscess (Quinsy).

<span class="mw-page-title-main">Tonsil stones</span> Mineralized debris within the crevices of the tonsils

Tonsil stones, also known as tonsilloliths, are mineralizations of debris within the crevices of the tonsils. When not mineralized, the presence of debris is known as chronic caseous tonsillitis (CCT). Symptoms may include bad breath, foreign body sensation, sore throat, pain or discomfort with swallowing, and cough. Generally there is no pain, though there may be the feeling of something present. The presence of tonsil stones may be otherwise undetectable, however some people have reported seeing white material in the rear of their throat.

<span class="mw-page-title-main">Lingual tonsils</span>

The lingual tonsils are a collection of lymphatic tissue located in the lamina propria of the root of the tongue. This lymphatic tissue consists of the lymphatic nodules rich in cells of the immune system (immunocytes). The immunocytes initiate the immune response when the lingual tonsils get in contact with invading microorganisms.

Gut-associated lymphoid tissue (GALT) is a component of the mucosa-associated lymphoid tissue (MALT) which works in the immune system to protect the body from invasion in the gut.

<span class="mw-page-title-main">Myeloid tissue</span> Tissue of bone marrow

Myeloid tissue, in the bone marrow sense of the word myeloid, is tissue of bone marrow, of bone marrow cell lineage, or resembling bone marrow, and myelogenous tissue is any tissue of, or arising from, bone marrow; in these senses the terms are usually used synonymously, as for example with chronic myeloid/myelogenous leukemia.

The mucosa-associated lymphoid tissue (MALT), also called mucosa-associated lymphatic tissue, is a diffuse system of small concentrations of lymphoid tissue found in various submucosal membrane sites of the body, such as the gastrointestinal tract, nasopharynx, thyroid, breast, lung, salivary glands, eye, and skin. MALT is populated by lymphocytes such as T cells and B cells, as well as plasma cells, dendritic cells and macrophages, each of which is well situated to encounter antigens passing through the mucosal epithelium. In the case of intestinal MALT, M cells are also present, which sample antigen from the lumen and deliver it to the lymphoid tissue. MALT constitute about 50% of the lymphoid tissue in human body. Immune responses that occur at mucous membranes are studied by mucosal immunology.

<span class="mw-page-title-main">Waldeyer's tonsillar ring</span>

Waldeyer's tonsillar ring is a ringed arrangement of lymphoid organs in the pharynx. Waldeyer's ring surrounds the naso- and oropharynx, with some of its tonsillar tissue located above and some below the soft palate.

<span class="mw-page-title-main">Adenoid hypertrophy</span> Medical condition

Adenoid hypertrophy is the unusual growth (hypertrophy) of the adenoid first described in 1868 by the Danish physician Wilhelm Meyer (1824–1895) in Copenhagen. He described a long term adenoid hypertrophy that will cause an obstruction of the nasal airways. These will lead to a dentofacial growth anomaly that was defined as "adenoid facies".

<span class="mw-page-title-main">Adenoiditis</span> Medical condition

Adenoiditis is the inflammation of the adenoid tissue usually caused by an infection. Adenoiditis is treated using medication or surgical intervention.

<span class="mw-page-title-main">Pharynx</span> Part of the throat that is behind the mouth and nasal cavity

The pharynx is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea. It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food to the esophagus and air to the larynx. The flap of cartilage called the epiglottis stops food from entering the larynx.

<span class="mw-page-title-main">Tonsillar crypts</span> Deep indentations in human tonsils

The human palatine tonsils (PT) are covered by stratified squamous epithelium that extends into deep and partly branched tonsillar crypts, of which there are about 10 to 30. The crypts greatly increase the contact surface between environmental influences and lymphoid tissue. In an average adult palatine tonsil the estimated epithelial surface area of the crypts is 295 cm2, in addition to the 45 cm2 of epithelium covering the oropharyngeal surface.

Lymph node stromal cells are essential to the structure and function of the lymph node whose functions include: creating an internal tissue scaffold for the support of hematopoietic cells; the release of small molecule chemical messengers that facilitate interactions between hematopoietic cells; the facilitation of the migration of hematopoietic cells; the presentation of antigens to immune cells at the initiation of the adaptive immune system; and the homeostasis of lymphocyte numbers. Stromal cells originate from multipotent mesenchymal stem cells.

The avian immune system is the system of biological structures and cellular processes that protects birds from disease.

Carcinoma of the tonsil is a type of squamous cell carcinoma. The tonsil is the most common site of squamous cell carcinoma in the oropharynx. It comprises 23.1% of all malignancies of the oropharynx. The tumors frequently present at advanced stages, and around 70% of patients present with metastasis to the cervical lymph nodes. . The most reported complaints include sore throat, otalgia or dysphagia. Some patients may complain of feeling the presence of a lump in the throat. Approximately 20% patients present with a node in the neck as the only symptom.


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