封面图片介绍

Cover Picture Introduction

甲状腺（Thyroid）是脊椎动物非常重要的腺体,位于颈部甲状软骨下方,气管两旁,是颈部的内分泌腺,甲状腺是人体中最大的内分泌腺,分为左右两叶,中间由较窄的峡部相联,呈H形。人的甲状腺形似蝴蝶,犹如盾甲,故以此命名。甲状腺分泌的主要活性物质有四碘甲状腺原氨酸（T4）和三碘甲状腺原氨酸（T3）,T3和T4是由碘和酪胺酸合成。

Thyroid is a very important gland in vertebrates that is located below the thyroid cartilage of the neck and on both sides of the trachea. It is the endocrine gland in the neck. The thyroid is the largest endocrine gland in the human body. It consists of two lobes and the middle is connected by narrow isthmus, which is in the shape of H. The human thyroid is like a butterfly and also like a shield armour, so it is named after it.