This is a body slice in the horizontal, or transverse, plane of the thigh of a male. The large yellow circle is the femur bone, and it is surrounded by dark red muscles and small blood vessel holes. Colored wax has been added to theses area to make them easier to identify. These body slices served as teaching tools for medical students in the 1930s and 1940s. They were provided by the Loyola University School of Medicine and the University of Illinois Department of Anatomy, and were refurbished by Michael Reese Hospital and Medical Center. The man and woman died of natural causes. Their bodies were frozen, cut into sections, and then preserved in glass containers filled with a formaldehyde solution.