Skull of Human Fetus and Adult
3D visualization reconstructed from scanned human data of fetal and adult skulls. The most complex part of the skeletal frame, the skull gives shape to the head and face, protects the brain, and houses the special sense organs. At birth, the skull bones (top left and right) are still incomplete and are connected by unossified fibrous remnants called fontanels. These allow the head of the infant to compress during birth and to accommodate brain growth during fetal lfe. The bones of the skull start to ossify late in the second month of development. It's comprised of 22 separate bones - 21 of which are butted and unit-welded together with fibrous joints so adhesive and durable that they function as one block; the other one hinged, allowing the lower jaw to drop. Air filled spaces (sinuses) in some of the bones surrounding the nasal cavity lighten the skull's weight and act as an echo chamber, adding resonance to the voice.