Development of the reproductive system

The development of the reproductive system is a part of prenatal development, and concerns the sex organs. It is a part of the stages of sexual differentiation. Because its location, to a large extent, overlaps the urinary system, the development of them can also be described together as the development of the urinary and reproductive organs.

The reproductive organs are developed from the intermediate mesoderm. The permanent organs of the adult are preceded by a set of structures which are purely embryonic, and which with the exception of the ducts disappear almost entirely before the end of fetal life. These embryonic structures are the Wolffian and Müllerian ducts, also known as mesonephric and paramesonephric ducts, respectively. The Wolffian duct remains as the duct in males, and the Müllerian as that of the female.

The mesonephric duct, also called the Wolffian duct, originates from a part of the pronephric duct.

In the outer part of the intermediate mesoderm, immediately under the ectoderm, in the region from the fifth cervical segment to the third thoracic segment, a series of short evaginations from each segment grows dorsally and extends caudally, fusing successively from before backward to form the pronephric duct. This continues to grow caudalward until it opens into the ventral part of the cloaca; beyond the pronephros it is termed the mesonephric duct. Thus, the mesonephric duct is what remains of the pronephric duct after the atrophy of the pronephros.

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