The cervix (from Latin "neck") is the neck of the uterus. This is the portion of the lower uterus, where the uterus joins with the top end of the vagina. The cervix is blocked during pregnancy by an antibacterial mucosal plug which helps to prevent infection. The mucous plug comes out as the cervix dialates in labor or shortly before.

During labor, contractions of the uterus will dilate the cervix to allow the child to pass through.

During orgasm, the cervix convulses in such a way as to draw any semen in the vagina into the uterus. This is thought to increase the likelihood of conception.

In humans it is associated with cervical cancer, a particular form of cancer which is detectable by cytological study of epidermal cells removed from the cervix in a process known as the pap smear.

The lymphatic drainage of the cervix is along the uterine arteries and cardinal ligaments to the parametrial, external iliac , internal iliac, obturator , and presacral lymph nodes. From these pelvic lymph nodes, drainage then proceeds to the paraaortic lymph nodes.