Birth gate

1. Yīn door.

2. The cervix of the uterus. The Wings to the Classified Classic ( 类经附翼 lèi jīng fù yì qiú zhèng lù, sān jiāo bāo luò mìng mén) states, At the bottom of the uterus is a door, which in women can be felt with the hand. This is commonly called chǎn mén.