Illustration of the spine from behind. From top to bottom: A part of the occipital bone (back of the head), followed by atlas and axis, as well as the five further cervical vertebrae. Those are followed by the twelve thoracic vertebrae, including the twelve ribs (costae). Farther down: The lumbal spine with the lumbal vertebrae I-V, then the sacral bone with the coccyx and on its side the iliac bone.
