Think of what you will be seeing and feeling as you perform your examination. I will give you some hints and Study Questions along the way to help you. Reproductive Embryology Sexual differentiation - Occurs in a sequential order. Spermatozoa are of two varieties e.g. 22 autosomes and either one X or one Y chromosome. There remains a great deal to be learned about the entire cascade of events that begins with an undifferentiated gonad and ends with an ovary or testis and both internal and external genitalia of matching sex.
Sex differentiation is a continuum of successive, overlapping embryologic events.
Gonadal a. Indifferent stage. Lasts until 8-9 or so weeks. The testis and ovary are derived from the same primordial tissue but histologic differentiation toward a testis occurs earlier than that toward an ovary. Primordial germ cells are originally near the yolk sac and traverse to the genital ridge for development into an ovary or testis. See Migration of Primordial Germ Cell Graphic 3.