ANATOMY

Detailed explanation-1: -Primordial germ cells originate in the endoderm of the yolk sac and migrate to the genital ridge to form the indifferent gonad.

Detailed explanation-2: -These primordial germ cells migrate to the developing gonads, which will form the ovaries in females and the testes in males. After a period of mitotic proliferation, the primordial germ cells undergo meiosis and differentiate into mature gametes-either eggs or sperm.

Detailed explanation-3: -Primordial germ cells (PGCs), precursors to sperm and eggs, have to migrate across the embryo to reach somatic gonadal precursors (SGPs) and fulfill their function.

Detailed explanation-4: -External endometriosis derives from primordial germ cells during the migration pathway from the yolk sac to the gonadal ridges (Fig. 1).

Detailed explanation-5: -The mesonephric tubules have inductive influences on the primordial gonads (germ cells) to drive the development of the indifferent gonad into testis. If the mesonephric tubules recede, the gonads will not differentiate and the indifferent gonads will remain as an ovary.