MRI scans on a light box. Silhouette of a doctor examining an array of colored MRI (magnetic resonance imaging) scans of the human body. Scans in the right half of the frame are of the brain; spinal and pelvic scans are seen at left. They show "slices" through the body, created from radio signals in a powerful magnetic field. The technique of MRI scanning is especially good for studying soft body tissues like the brain, heart and spinal cord.
Skull anatomy by Leonardo da Vinci. Historical artwork and notes on the anatomy of the human skull and teeth, by the Italian artist and scientist Leonardo da Vinci (1452-1519). This bisected skull shows the external structure (right), and dissected facial sinuses (left), the air-filled spaces inside the bones of the face. The diagram at lower left shows the teeth present in one half of the mouth: 4 incisors, 2 canines, 4 pre-molars, and 6 molars.