The smallest bones in the body are found in the ear. The longest
bone in the body is the femur. The bones are filled with a fatty
substance called bone marrow. In this marrow, red and white blood cells
are manufactured and then released into the bloodstream.
Over half the body's bones are in the hands and feet. The only jointless
bone in your body is the hyoid bone in your throat. As your bones grow,
you get taller (of course). Your growth in height is likely to stop by
the time you are 16 if you're a girl and 18 if you're a boy.