When we look at fossilized bones of dinosaurs and other prehistoric animals, it is easy to see how they are strongand rigid enough to provide support for the animals’ large bodies. What may not be as obvious is that an organism’s skeletal systemis made up of living tissue with several important functions within the body.Functions of the SkeletonSupportThe skeleton’s bones give support and shape to the body.ProtectionBones protect the internal organs of the body. MovementThe skeleton has a system of joints and levers that coordinate with muscles to produce movement.Mineral StorageBones contain reserves of minerals, such as calcium, that are important to processes in the body. Whenever calcium levels in the blood are low, some of the stored calcium is released from the bones. Blood Cell FormationBlood cells are produced in the soft marrow tissue that fills the internal cavities of some bones.The human skeleton can be divided into two regions: theaxial skeletonand theappendicular skeleton. The axial skelton is made up of the skull, mandible, and the vertebrae in the spinal column. The appendicular skeleton is made up of the rest of the bones, such as those in the arms and legs.Bone StructureBones are living tissue made up of several distinct layers. Explore those layers in the interactive below.
PeriosteumThe rigid outside of the bone is a tough layer of connective tissue called the periosteum.