The collecting ducts of the efferent epididymal ducts subsequently open into the Wolffian duct
, which carries sperm to the cloaca (Figs.
At 10 weeks, in the absence of threshold levels of androgen and Mullerian inhibiting factors, the Mullerian ducts develop, the Wolffian ducts
regress, and differentiation of the female external genitalia begins.
 In a human fetus the Mullerian and Wolffian ducts
are both present at 7 weeks of gestation.
On pathological analysis of laparoscopic paraovarian and paratubal cyst biopsy material, tissues differentiated as both Mullerian and Wolffian ducts
At stage 17, the Mullerian duct appears via a deep invagination at the level of the 3rd thoracic somite and proceeds to grow caudally towards the Wolffian ducts
until fusion in stage 18.
The embryonic residual theory states that endometriotic tissues occur from the residual tissue of Mullerian and Wolffian ducts
. The backflow of menstrual blood occurs in approximately 90% of reproductive females; therefore, the implantation theory makes sense in that menstrual blood moves back into the fallopian tubes and reaches the peritoneal cavity, and the endometrial tissues in the menstrual blood become implanted in the peritoneum .
The upper Wolffian ducts
fail to develop, so no internal male organs are present.
develop from the mesonephric kidney system (mesoderm), which leads to the development of uterus and upper vagina.
Here's a sample entry: "Wolffian ducts
: also called mesonephric ducts; paired ducts that develop during vertebrate development; in human males, they give rise to the vasa deferentia, and in human females, they are relatively undeveloped.
Gupta and Das postulated that adherence and fusion of the developing wolffian ducts
takes place early and that descent of one testis causes the other one to follow it toward the same hemiscrotum.
Adhesion or fusion of developing Wolffian ducts
, defective development of ipsilateral gubernaculum, testicular adhesion, defective formation of the internal inguinal ring, traction on a testis by persistent Mullerian structures and possibility of the development of both testes from the same germinal ridge, are various postulated theories for the ectopic testis.
Testosterone, a steroid, stimulates development of the Wolffian ducts
leading to formation of the epididymis and ductus deferens, the duct system that drains the testes.