Uterus and Cervix

The uterus, or womb, provides a nourishing environment for implantation and development of a fertilized egg. This hollow, pear-shaped organ supports and protects a developing fetus throughout pregnancy, creating ideal conditions for embryonic growth and fetal maturation until birth occurs.

The uterus is positioned in the pelvic cavity between the urinary bladder and the rectum. It typically tilts forward at its base, covering the bladder from above. This central location within the pelvis allows the organ to be securely anchored and protected while maintaining accessibility for reproductive functions.

Three primary ligaments support the uterus: broad ligaments on either side, round ligaments, and uterosacral ligaments. These paired suspensory ligaments anchor the uterus within the pelvic cavity, providing structural integrity and support as the organ enlarges during pregnancy and maintains its position.

The uterus consists of three main regions: the fundus, the rounded upper portion above the uterine tubes; the body, which houses the uterine cavity; and the cervix, a tubular structure that narrows at the isthmus before extending into the vagina. These regions work together to support pregnancy and facilitate menstrual flow.

The internal os is the opening from the uterine cavity into the cervical canal, while the external os opens into the vagina. These two openings allow passage of menstrual flow and provide an entry point for sperm while protecting the uterine environment from external infections and facilitating childbirth.

A non-gravid uterus typically measures approximately 7-8 centimeters in length, 5 centimeters in width, and 2.5 centimeters in thickness. These dimensions vary based on factors such as age and pregnancy history, reflecting individual differences in reproductive anatomy and prior reproductive experiences.

The cervix serves multiple reproductive functions through its two distinct openings. The internal os connects the uterine cavity to the cervical canal, while the external os opens into the vagina. These openings allow menstrual flow passage and sperm entry while the cervical canal protects the uterine environment from external infections.