Perimetrium
Perimetrium (tunica serosa uteri)
The outer serous coat of the uterus — visceral peritoneum with a thin layer of connective tissue — continuous laterally with the broad ligament and reflected onto the bladder and rectum.
Overview
The perimetrium covers the fundus and body of the uterus. Anteriorly it reflects onto the bladder at the level of the isthmus, forming the vesicouterine pouch; the anterior surface of the cervix below this has no peritoneal covering (adventitia only), which allows the lower uterine segment to be reached without opening the main peritoneal cavity widely at caesarean section. Posteriorly it extends further down, over the supravaginal cervix and the posterior fornix of the vagina, before reflecting onto the rectum as the rectouterine pouch (of Douglas). Laterally the two layers leave the uterus as the broad ligament.
- Location
Outer surface of the uterine fundus and body (and posterior supravaginal cervix).
Anatomy
- Histology
Mesothelium (simple squamous) on a thin layer of loose connective tissue (subserosa).
Function
- Provides a smooth, lubricated surface that allows the uterus to move and expand against neighbouring organs.
Clinical significance
Pouch of Douglas
Fluid, blood (ruptured ectopic), pus and metastatic deposits collect in the rectouterine pouch, the most dependent part of the female peritoneal cavity; it can be assessed by transvaginal ultrasound or posterior-fornix examination.
Compiled from standard anatomy and physiology references — see the Reproductive System sources. For education only; not medical advice.