The urachus is a structure that exists during the fetal period, connecting the bladder and the navel.

This pipe is for carrying water.

He underwent surgery for a ureteral stone.

This pipe is for carrying water.

What is this pipe used for?

The allantois plays an important role in the development of the fetus.

I am studying the philosophy of Guanzi.

The water pipe is broken and water is leaking.

This old radio uses a vacuum tube.

The male reproductive organs include the vas deferens.