Waldeyer's tonsillar ring (pharyngeal lymphoid ring, Waldeyer's lymphatic ring, or tonsillar ring) is a ringed arrangement of lymphoid organs in the

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

. Waldeyer's ring surrounds the naso- and

oropharynx The pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its ...

, with some of its tonsillar tissue located above and some below the

soft palate The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft biological tissue, tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is ...

(and to the back of the mouth cavity).

Structure

The ring consists of the (from top to bottom): * 1 pharyngeal tonsil (or "adenoid"), located on the roof of the nasopharynx, under the sphenoid bone. * 2

tubal tonsil The tubal tonsil, also known as Gerlach tonsil, is one of the four main tonsil groups forming Waldeyer's tonsillar ring. Structure Each tubal tonsil is located posterior to the opening of the Eustachian tube on the lateral wall of the nasoph ...

s on each side, where each

auditory tube The Eustachian tube (), also called the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in diameter. It ...

opens into the nasopharynx * 2

palatine tonsil 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 in humans and other mammals, which can often be seen as flesh-colored, pinkish ...

s (commonly called "the tonsils") located in the oropharynx * lingual tonsils, a collection of lymphatic tissue located on the back part of the

tongue The tongue is a Muscle, muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper s ...

Terminology

Some authors speak of two pharyngeal tonsils/two adenoids. These authors simply look at the left and right halves of the pharyngeal tonsil as two tonsils. Many authors also speak of lingual tonsils (in the plural), because this accumulation of lymphoid tissue consists of a number of little prominences – many smaller rounded masses. Whether to collectively call all these a single tonsil or separate tonsils is to an extent an arbitrary decision.

Variation

There also normally is a good amount of

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

-associated

lymphoid tissue 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, lympha ...

(

MALT Malt is any cereal grain that has been made to germinate by soaking in water and then stopped from germinating further by drying with hot air, a process known as "malting". Malted grain is used to make beer, whisky, malted milk, malt vinegar, ...

) present between all these tonsils (intertonsillar) around the ring, and more of this lymphoid tissue can variably be found more or less throughout at least the naso- and oropharynx.

Development

The tubal tonsils usually develop from an accumulation of lymphoid tissue in the pharyngeal tonsil.

Clinical significance

The

s when inflamed/swollen, more common in children, can obstruct respiration. Inflammation of the tonsils is called

tonsillitis 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 en ...

and removal is called

tonsillectomy 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 wit ...

Etymology of Waldeyer's ring

Waldeyer's ring was named after the nineteenth-century

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

Heinrich Wilhelm Gottfried von Waldeyer-Hartz Heinrich Wilhelm Gottfried von Waldeyer-Hartz (6 October 1836 – 23 January 1921) was a German anatomist, known for summarizing neuron theory and for naming the chromosome. He is also remembered by anatomical structures of the human body which ...

Other animals

Some animals, but not humans, have one or two additional tonsils: * Soft palate tonsil * Paraepiglottic tonsil

References

{{Lymphatic organ anatomy Lymphatics of the head and neck Tonsil Lymphoid organ Pharynx