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

The genital ridge (or gonadal ridge) is the 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.