A two-lobed endocrine gland found in all vertebrates, located in front of and on either side of the trachea in humans, and producing various hormones, such as triiodothyronine and calcitonin[BTO]. [ http://en.wikipedia.org/wiki/Thyroid http://purl.obolibrary.org/obo/BTO_0001379 ]

Synonyms: thyroid

This is just here as a test because I lose it

Term information

database cross reference

uberon_slim, efo_slim, pheno_slim, organ_slim

depicted by


external definition

Either of paired structures located in the throat which develop from the ventral wall of the pharynx and excretes hormones involved in the morphological and functional changes during metamorphosis as well as influencing other tissues.[AAO]

has related synonym

glandula thyroidea

homology notes

(...) at some stage of its development, every chordate exhibits five uniquely derived characters or synapomorphies of the group: (...) (2) a groove in the pharyngeal floor known as the endostyle, or a thyroid gland derived from part of the endostyle (...).[well established][VHOG]



taxon notes

In tetrapods, the thyroid is always found somewhere in the neck region. In most tetrapod species, there are two paired thyroid glands - that is, the right and left lobes are not joined together. However, there is only ever a single thyroid gland in most mammals, and the shape found in humans is common to many other species
In larval lampreys, the thyroid originates as an exocrine gland, secreting its hormones into the gut, and associated with the larva's filter-feeding apparatus. In the adult lamprey, the gland separates from the gut, and becomes endocrine, but this path of development may reflect the evolutionary origin of the thyroid. For instance, the closest living relatives of vertebrates, the tunicates and Amphioxus, have a structure very similar to that of larval lampreys, and this also secretes iodine-containing compounds (albeit not thyroxine)
In fish, it is usually located below the gills and is not always divided into distinct lobes. However, in some teleosts, patches of thyroid tissue are found elsewhere in the body, associated with the kidneys, spleen, heart, or eyes