Muscles in a male body (c. 1510) by artist Leonardo da Vinci (1452-1519). This sketch or drawing is a vintage Renaissance Era fine art science painting featuring human anatomy, the leg, thighs, buttocks and back muscle structure of a man in profile. Sketch from one of Leonardo da Vinci's many journals. Leonardo kept a series of journals in which he wrote almost daily, as well as separate notes and sheets of observations, comments and plans which were left to various pupils and were later bound. Many of the journals have survived to illustrate Leonardo's studies, discoveries and inventions. Most of the journals were written backwards in mirror script. His journals were later published, 165 years after his death.