Recto: The bladder. Verso: The lungs

Recto: two studies showing the kidneys; three views of the bladder and urethra; a detail of the entry of the ureter into the bladder; a faint drawing of the same organs as shown in RCIN 919070r; notes on the drawings. Verso: a study of the thoracic and abdominal organs, probably of a pig, separated by the diaphragm and related to the spinal column; the structure of the lungs seen from the front; notes on the drawings. Though Leonardo had access to human material, he also conducted animal dissections. The subject here was probably a pig, commonly used for anatomical investigation through the ages. On the verso of this sheet Leonardo adjusts the proportions and orientation so that the lungs seem human at first glance, and attempts to convey the branching of the bronchi by rendering the lungs semi-transparent; on the left he includes the heart, oesophagus and great vessels, and on the right, the liver, stomach and spleen nestling in the curve of the diaphragm, and the structures of the neck above – the trachea, oesophagus, carotids and vertebral column, with the long vertebral processes of a pig. Leonardo first studied anatomy in the late 1480s, and by the end of his life he claimed to have performed 30 human dissections. He intended to publish an illustrated treatise on the subject, but this was never completed, and the work of one of the great anatomists of the Renaissance thus had no discernible impact on the discipline. Text adapted from Leonardo da Vinci, A life in drawing, London, 2018