What is urogenital ridge?

In embryology, the gonadal ridge (or urogenital ridge) is the precursor to the gonads. The gonadal ridge initially consists mainly of mesenchyme and cells of underlying mesonephric origin. The gonadal ridge appears at approximately five weeks, and gives rise to the sex cords.

Where is the urogenital ridge?

The urogenital ridge, from which the urogenital system will derive, arises at approximately the 4th week of gestation in the intermediate mesoderm. The indifferent gonad (gonadal ridge), identical in females and males, emerges on the ventromedial surface of the mesonephros as a derivative of the intermediate mesoderm.

Where does the gonadal ridge come from?

The gonadal ridge These are bilateral, ridge-like protrusions that appear ventromedially to the nephrogenic cord. They are generated in the 5th week through the proliferation of the coelomic epithelium and the thickening of the underlying mesenchyma.

What is the Mesonephric Ridge?

(mez’ō-nef’rik rij) A ridge that, in early human embryos, comprises the entire urogenital ridge; however, later in development a more medial genital ridge, the potential gonad, is demarcated from it. See also: urogenital ridge.

Where does the urogenital ridge start and end?

The urogenital ridge as a whole arises from the intermediate lateral plate mesoderm. At approximately 9 days post coitum (dpc), this mesoderm forms two elongated mounds on the coelomic surface of the dorsal side of the embryo. These lie to either side of the neural tube and extend almost the length of the body cavity.

When does the urogenital system begin to develop?

The urogenital system arises during the fourth week of development from urogenital ridges in the intermediate mesoderm on each side of the primitive aorta. The nephrogenic ridge is the part of the urogenital ridge that forms the urinary system.

Is the nephrogenic Ridge part of the urinary system?

The nephrogenic ridge is the part of the urogenital ridge that forms the urinary system. Three sets of kidneys develop sequentially in the embryo: The pronephros is rudimentary and nonfunctional, and regresses completely. The mesonephros is functional for only a short period of time, and remains as the mesonephric (Wolffian) duct.

What are genes involved in urogenital ridge differentiation?

Wilms tumor (WT1), EMX2, LIM1, CBX2, and steroidogenic factor-1 (SF1) play roles in differentiation of gonad from urogenital ridge. Genes involved in testicular differentiation include SF-1, SOX9, sex-determining region on Y (SRY), and anti-Mullerian hormone (AMH).