part of
part of
has developmental contribution from
transformation of
endocrine system
thyroid gland
(...) 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]
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].
AAO:0010544
BTO:0001379
CALOHA:TS-1047
EFO:0000861
EHDAA2:0002028
EHDAA:2148
EHDAA:2975
EMAPA:17068
EV:0100133
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]
FMA:9603
GAID:465
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
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 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
MA:0000129
MAT:0000081
MESH:D013961
MIAA:0000081
OpenCyc:Mx4rvVjLT5wpEbGdrcN5Y29ycA
UBERON:0002046
UMLS:C0040132
VHOG:0000418
XAO:0000162
galen:ThyroidGland
glandula thyroidea
thyroid
uberon
neural crest
endocrine gland
endoderm-derived structure
thyroid diverticulum
structure with developmental contribution from neural crest