Around the bone chain, there were 3 layers of structure: skin, subcutaneous tissues and muscular layers.

尾椎链的外面覆以三层结构，即皮肤、皮下组织和肌层。

youdao

So organs are made up of combinations of tissues where all the tissues are collections of cells that are doing some function, nervous tissue, muscular tissue, epithelial tissue, those are examples of tissues that form organs.

所以器官是由各种组织组合而成,所有的组织都是,具有某些功能的细胞集合,神经组织,肌肉组织,上皮组织,这些都是由组织构成器官的例子

耶鲁公开课 - 生物医学工程探索课程节选