Development
The urinary and reproductive organs are developed from the intermediate mesoderm. The permanent organs of the adult are preceded by a set of structures that are purely embryonic, and that, with the exception of the ducts, disappear almost entirely before the end of fetal life. These embryonic structures are on either side: the pronephros, the mesonephros and the metanephros of the kidney, and the Wolffian and Müllerian ducts of the sex organ. The pronephros disappears very early; the structural elements of the mesonephros mostly degenerate, but the gonad is developed in their place, with which the Wolffian duct remains as the duct in males, and the Müllerian as that of the female. Some of the tubules of the mesonephros form part of the permanent kidney.
Read more about this topic: Genitourinary System
Famous quotes containing the word development:
“The American has dwindled into an Odd Fellow—one who may be known by the development of his organ of gregariousness.”
—Henry David Thoreau (1817–1862)
“This was the Eastham famous of late years for its camp- meetings, held in a grove near by, to which thousands flock from all parts of the Bay. We conjectured that the reason for the perhaps unusual, if not unhealthful development of the religious sentiment here, was the fact that a large portion of the population are women whose husbands and sons are either abroad on the sea, or else drowned, and there is nobody but they and the ministers left behind.”
—Henry David Thoreau (1817–1862)
“The young women, what can they not learn, what can they not achieve, with Columbia University annex thrown open to them? In this great outlook for women’s broader intellectual development I see the great sunburst of the future.”
—M. E. W. Sherwood (1826–1903)