The cervix is the lower, narrow part of the uterus (womb) that connects the uterus to the vagina and acts as a gateway between them.

Quick Scoop: What is a cervix?

  • It’s the “neck” of the uterus – the small canal between the uterus and the vagina.
  • It’s usually around 2–4 cm long and a few cm wide, though size and shape vary with age, childbirth, and hormones.
  • It has an opening toward the uterus (internal os) and an opening toward the vagina (external os), with a canal (cervical canal) in between.
  • The part you could potentially feel at the top of the vagina is the outer portion called the ectocervix.

Where it is and what it does

  • Location: At the very top of the vagina, forming the bottom end of the uterus.
  • Main roles:
    1. Lets menstrual blood flow out from the uterus into the vagina.
2. Lets sperm travel from the vagina up into the uterus during sex.

3. Changes during the menstrual cycle (position, firmness, mucus) to help or limit sperm movement.

4. During labor, it softens and opens (dilates) so a baby can pass from the uterus into the vagina.

A quick mental picture

You can think of the cervix like a small tunnel at the bottom of a room:

  • The “room” is the uterus.
  • The “hallway” below is the vagina.
  • The cervix is the short tunnel between them, with an inner doorway to the uterus and an outer doorway to the vagina.

Information gathered from public forums or data available on the internet and portrayed here.