Development of the Uterus, Uterine Tubes, and Vagina
The female reproductive tract
Includes the uterine tubes, uterus, and vagina
Paramesonephric ducts (aka, Mullerian Ducts)
- Emerged as a groove in the intermediate mesoderm, parallel to the mesonephric ducts, during week 6.
- The following genetic signals aid in their cranial to caudal growth:
- Wnt4 is necessary for early growth of the paramesonephric ducts
- Wnt9b ensures growth in the caudal direction
- Wnt7a is thought to be essential for their normal development
- Ducts grow towards, and make contact with, the urogenital sinus (an endoderm-derived structure).
- ~Week 10, paramesonepheric ducts begin to fuse
- Uterine septum temporarily lies in midline, where the edges of the two paramesonephric ducts meet.
- Cranial ends remain open
- Where caudal ends meet urogenital sinus, the vaginal plate forms
- Mesonephros degnerates
Mature Form
- Uterine tubes derive from cranial portions of the paramesonephric ducts
- Uterine cavity and upper vagina derive from caudal portions of paramesonephric ducts
- Uterine ligaments = broad ligament extending laterally and round ligament attaching to labia majora
- Fornices of vagina extend outward, over cervix of uterus
- Lower vagina (possibly) derives from urogenital sinus
- Hymen = membranous covering of vagina
- Ovaries lie between uterus and distal ends of uterine tubes
- Descend from abdominal cavity, guided and stabilized by genital ligaments
- Ovarian ligaments = suspensory ligament of the ovary and ovarian ligament