thyroid gland 甲状腺 (...) 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 (...)在其发展的某个阶段，每种脊索动物都表现出该组的五个独特的衍生特征或突触：(...)(2)咽底中的凹槽，称为内柱，或源自内柱的一部分的甲状腺(...)。[well established][VHOG] 任一种位于咽喉中的成对结构，都从咽的前壁发育而来，分泌激素，参与变态过程中的形态和功能变化，并影响其它组织。[AAO] 在四足动物中，甲状腺通常位于颈部。在大多数四足动物中，有两对甲状腺--也就是说，右叶和左叶没有连接在一起。然而，在大多数哺乳动物中只有一个甲状腺，在人类中发现的这种形状在许多其他物种中是常见的。 在幼虫七鳃鳗中, 甲状腺起源于外分泌腺，分泌激素进入肠道，与幼虫的滤食器有关。在成年七鳃鳗中，腺体与肠道分离，并变成内分泌腺，但是这种发育路径可能反映甲状腺的进化起源。例如，脊椎动物最接近的近亲--金枪鱼和文昌鱼--的结构与幼虫七鳃鳗的结构非常相似，而且还分泌含碘化合物（尽管不是甲状腺素）。 在所有脊椎动物中发现的两瓣内分泌腺，位于人类气管的前部和两侧，并产生各种激素，如三碘甲状腺原氨酸和降钙素[BTO]。 在鱼中，它通常位于鳃下面，并不总是分成明显的叶。然而，在一些硬骨鱼类中，在身体的其他部位发现甲状腺组织的斑块，其与肾脏、脾脏、心脏或眼睛有关。 甲状腺(glandula thyroidea) 甲状腺(thyroid) endocrine gland 内分泌腺 endoderm-derived structure 内胚层衍生结构 structure with developmental contribution from neural crest 神经嵴发育的结构