Genital ridge

Genital ridge
Genital ridge
	Section of the fold in the mesonephros of a chick embryo of the fourth day. (Genital ridge labeled at left.)
Details
Precursor	Urogenital folds
Gives rise to	Sex cords
System	Reproductive system
Identifiers
Latin	crista gonadalis
TE	ridge_by_E5.7.1.0.0.0.5 E5.7.1.0.0.0.5
	Anatomical terminology

In embryology, the genital ridge (genital fold or gonadal ridge) is the developmental precursor to the gonads. The genital ridge initially consists mainly of mesenchyme and cells of underlying mesonephric origin. Once oogonia ^{[clarification needed]} enter this area they attempt to associate with these somatic cells. Development proceeds and the oogonia become fully surrounded by a layer of cells (pre-granulosa cells).

The genital ridge appears at approximately five weeks, and gives rise to the sex cords.

A.—Diagram of the primitive urogenital organs in the embryo previous to sexual distinction.
* 3. Ureter.
* 4. Urinary bladder.
* 5. Urachus.
* cl. Cloaca.
* cp. Elevation which becomes clitoris or penis.
* i. Lower part of the intestine.
* ls. Fold of integument from which the labia majora or scrotum are formed.
* m, m. Right and left Müllerian ducts uniting together and running with the Wolffian ducts in gc, the genital cord.
* ot. The **genital ridge** from which either the ovary or testis is formed (upper right).
* ug. Sinus urogenitalis.
* W. Left Wolffian body.
* w, w. Right and left Wolffian ducts.