Colombo's anatomical text consisted of 15 different books, each of which covered information concerning a different part of the body. Book 1 described the bones, while Book 2 and Book three, respectively, outlined the cartilages and ligaments that could be found within the human body. Book 4 explains the skeleton as a whole, bringing together the individually discussed anatomical elements described in the preceding three books. The muscles of the human body are described in Book 5, and the liver and veins share the content of Book 6. Book 7 explains the heart and arteries and is followed by a Book 8's discussion of the brain and nerves. Glands in general are described in Book 9, and Book 10 is dedicated to the explanation of the eyes. The viscera are covered in Book 11. Book 12 outlines the formation of the fetus while book 13 details the covering of the human body, or skin. Vivisections, a practice used regularly by Colombo are described in Book 14. Book 15 closes out the anatomical text by listing things Colombo himself saw that fell under the category of "things rarely seen in anatomy."
