Leonardo had continually studied the structure of the body in order to be able to depict the human figure properly. In 1510 in Pavia, Leonardo and Marcantonio della Torre, a professional anatomist at the University of Pavia, started dissecting corpses. This collaboration raised Leonardo's research to a higher scientific level that showed itself in the quality of his drawings. In these studies it is no longer merely a question of discovering what physically exists; instead, the interplay of bones, muscles and tendons comes to fore.

After Marcantonio della Torre died of the plague in 1511, Leonardo's practical opportunities for pursuing an intensive examination of corpses probably diminished, but the structure of the human body continued to interest him in his drawings.

The study of embryos is one of Leonardo's most impressive anatomical drawings. However, it is certain that Leonardo did not dissect a pregnant corps; instead he applied his examinations of animal embryos to humans.

Preview	Picture Data	Info
	Vitruvian Man 1492 Pen, ink, watercolour and metalpoint on paper, 343 x 245 mm Gallerie dell'Accademia, Venice
	Study on the proportions of head and eyes - Pen and ink, 197 x 160 mm Biblioteca Reale, Turin
	Comparison of scalp skin and onion 1489 Pen, ink and red chalk on paper, 203 x 152 mm Royal Library, Windsor
	Studies of human skull 1489 Pen, ink and black chalk on paper, 188 x 134 mm Royal Library, Windsor
	Study of proportion c. 1490 Silverpoint on blue prepared paper, 213 x 153 mm Royal Library, Windsor
	Anatomical studies of the shoulder 1510-11 Black chalk, pen and ink on paper, 289 x 199 mm Royal Library, Windsor
	Anatomical studies of a male shoulder 1509-10 Pen and ink on paper, 292 x 198 mm Royal Library, Windsor
	Anatomical studies (larynx and leg) 1510 Drawing Royal Library, Windsor
	Heart and its Blood Vessels - Drawing Biblioteca Ambrosiana, Milan
	Studies of the sexual act and male sexual organ c. 1492 Pen and ink on paper, 273 x 202 mm Royal Library, Windsor
	Anatomical studies 1504-06 Pen on red prepared paper, 253 x 197 mm Biblioteca Reale, Turin
	Studies of legs of man and the leg of a horse 1506-07 Pen, ink, red chalk on red prepared paper, 285 x 205 mm Royal Library, Windsor
	Drawing of a Woman's Torso - Drawing Biblioteca Ambrosiana, Milan
	Drawing of the Torso and the Arms - Drawing Biblioteca Ambrosiana, Milan
	Studies of embryos 1509-14 Black and red chalk, pen and ink wash on paper, 305 x 220 mm Royal Library, Windsor