tonsils

Examples of tonsils in the following topics:

• Tonsils

  • The tonsils are small masses of secondary lymphoid tissue located in the pharynx.
  • There are four pairs of tonsils located within the pharynx.
  • The palatine tonsils are located in the sides of the oropharynx.
  • Captured antigens are presented to B and T cells within the tonsil, then the B cells migrate to germinal centers within the tonsil as an adaptive immune response is initiated.
  •  Tonsil removal (tonsillectomy) is a common procedure to treat swollen and infected lymph nodes (tonsillitis).

• Tonsillectomy

  • A tonsillectomy is a surgical procedure in which the tonsils are removed from either side of the throat.
  • Figure 1 shows a case of acute tonsillitis in children.
  • Figure 2 is a picture of the tonsils removed from a patient.
  • The generally accepted procedure for tonsillectomy involves separating and removing the tonsils from the subcapsular plane – a fascia of tissue that surrounds the tonsils.
  • After the tonsil is removed from its position, a snare can be used to make a small cut on the lower portion prior to removal of the tonsil.

• Pharynx

  • The adenoids (pharyngeal tonsils) are a mass of lymphatic tissue found in the roof of the nasopharynx.
  • The oropharynx contains the palatine tonsils, which are masses of lymphoid tissue found on the lateral walls of the oropharynx.
  • Compared to the adenoids of the nasopharynx, the palatine tonsils contain many folds (called crypts), and aren't ciliated like the adenoids are.
  • These tonsils are also occasionally removed in people with infection or enlargement.
  • Unlike the nasopharynx and oropharynx, there are no tonsils in the laryngopharynx.

• Pharynx

  • The pharyngeal tonsils, more commonly referred to as the adenoids, are lymphoid tissue structures located in the posterior wall of the nasopharynx.
  • The posterior wall of the nasopharynx holds the pharyngeal tonsils, which can be especially marked in childhood.
  • Superior to the pharyngeal tonsil, in the midline, an irregular flask-shaped depression of the mucous membrane sometimes extends upward; it is known as the pharyngeal bursa.
  • It opens anteriorly, through the isthmus faucium, into the mouth, and contains the palatine tonsil—another grouping of adenoid tissue.
  • The lateral walls are made up of the tonsil and associated tonsilar tissues.

• Lymphoid Tissue

  • It is found mainly in the lymph nodes, but also in the lymphoid follicles in tonsils, Peyer's patches, spleen, adenoids, skin, and other areas associated with the mucosa-associated lymphoid tissue (MALT).
  • In addition to supporting B and T lymphocyte activation, other secondary lymphoid organs perform other unique functions, such as the spleen's ability to filter blood and the tonsil's ability to capture antigens in the upper respiratory tract.
  • The thymus and bone marrow are primary lymphoid tissue, while the lymph nodes, tonsils, and spleen are secondary lymphoid tissue.

• Cells and Organs of the Immune System

  • The key primary lymphoid organs of the immune system include the thymus and bone marrow, as well as secondary lymphatic tissues including spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin, and liver.
  • The palatine tonsils and the nasopharyngeal tonsil are lymphoepithelial tissues located near the oropharynx and nasopharynx.
  • The fundamental immunological roles of tonsils aren't yet understood.

• Fusobacteria

  • Once this sore develops into a peritonsillar abscess, the pocket is filled with pus and bacteria in close proximity to the tonsils.

• Glossopharyngeal (IX) Nerve

  • It receives general sensory fibers (ventral trigeminothalamic tract) from the tonsils, the pharynx, the middle ear, and the posterior 1/3 of the tongue.

• Structure of the Lymphatic System

  • Lymphoid tissue is found in many organs including the lymph nodes, as well as in the lymphoid follicles in the pharynx such as the tonsils.

• Double-Stranded DNA Viruses: Adenoviruses

  • These often show up as conjunctivitis, tonsillitis, ear infection, or croup.
  • A combination of conjunctivitis and tonsillitis is particularly common with adenovirus infections.