The cervix is a narrow, cylindrical structure located at the lower end of the uterus in the female reproductive system. It serves as a passageway between the uterus and the vagina, playing a crucial role during childbirth by dilating to allow the baby to pass through. The cervix also produces mucus that changes in consistency throughout the menstrual cycle, helping to either facilitate or block sperm entry. During a Pap smear, a common screening test, cells are collected from the cervix to check for abnormalities that could indicate conditions like cervical cancer. Regular check-ups are important for maintaining reproductive health and catching any potential issues early.