Why are the infants skull joints moveable?

The skull of a newborn baby is made up of several plates of bone that are not yet fused together. This allows the skull to be flexible and to mold itself to the birth canal during delivery. The joints between the skull bones are also moveable, which allows the brain to grow rapidly during the first few months of life. As the brain grows, the skull bones gradually fuse together, until they are fully fused by adulthood.

Here are some specific reasons why the infant skull joints are moveable:

* To allow for brain growth: The brain of a newborn baby is about 25% of its adult size. Over the next few months, the brain will grow rapidly, reaching about 75% of its adult size by the end of the first year. This rapid growth requires the skull bones to be moveable so that they can expand and accommodate the growing brain.

* To protect the brain: The moveable skull joints help to protect the brain from injury. If the skull bones were fused together, they would be more likely to fracture in the event of a fall or other head injury. The moveable joints allow the skull to absorb some of the impact of a blow, which helps to protect the brain from damage.

* To facilitate birth: The moveable skull joints allow the skull to mold itself to the birth canal during delivery. The skull can compress and elongate as it passes through the birth canal, which helps to reduce the risk of injury to the baby's head.

Once the brain has reached its full size, the skull bones gradually fuse together. This process of fusion is called cranial ossification. It begins in the first few months of life and is usually complete by adulthood. The fusion of the skull bones helps to protect the brain and to give the skull its adult shape.