External Genitalia
Until about the ninth week of gestational age, the external genitalia of males and females look the same, and follow a common development. This includes the development of a genital tubercle and a membrane dorsally to it, covering the developing urogenital opening, and the development of labioscrotal folds.
Even after differentiation can be seen between the sexes, some stages are common, e.g. the disappearing of the membrane. On the other hand, sex-dependent development include further protrusion of the genital tubercle in the male to form the penis. Furthermore, the labioscrotal folds evolve into the scrotum in males, while they evolve into labia in females.
Read more about this topic: Development Of The Urinary And Reproductive Organs
Famous quotes containing the word external:
“The ideal of brotherhood of man, the building of the Just City, is one that cannot be discarded without lifelong feelings of disappointment and loss. But, if we are to live in the real world, discard it we must. Its very nobility makes the results of its breakdown doubly horrifying, and it breaks down, as it always will, not by some external agency but because it cannot work.”
—Kingsley Amis (1922–1995)