Why are the bones in the cranium fused?
cranium bones are fused to protect the delicate brain from bumps and knocks
The skull or cranium is also called the brain case. All the bones of the skull (except the mandible) are firmly interlocked along structures called sutures. Cranium or brain case or helmet is composed of eight bones including the frontal, occipital, sphenoid, and ethmoid bones, along with a pair of parietal and temporal bones. The skull, in an adult, is only one bone made of 8 fused bones. The lower jaw or mandible, is not…
The skull, or cranium (as it is medically termed. It is made up of fused bones; the frontal bone, the temporal bones, the parietal bones and the occipital bone; and other minor bones are also involved in protecting the brain, such as the sphenoid bone and ethmoid bone. The skull protects your brain.
The exterior cranial bones are the two frontal bones (fused together in adulthood to constitute the forehead), the two parietal bones (the top of the head), the two temporal bones, and the occipital bone. The internal cranial bones are the ethmoid bone and the sphenoid bone. Part of the occipital bone is also included as an internal cranial bone.
The bones of a fetal skull are relatively soft and pliable. Also, they are not yet fused together. These features allow for a certain amount of compression and flexibility when the baby passes through the birth canal. In contrast, the adult skull is comprised of several hard thick bones that are firmly fused together. This provides maximum protection from trauma to the cranium.
Can the bones in your foot be surgically fused together to correct ankle-roll and foot-drop you are a left hemaplegic?
There are 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, the 5 sacral vertebrae fused to form the sacrum, and the 4 coccygeal vertebrae fused to form the coccyx. Depending on the way you count the number of bones, it comes to as few as 26 bones (just the fused sacrum and fused coccyx are counted) or 33 bones (if you count each bone that is fused).