Spine and ribcage
The spine is the most important bone in the body. It is the long series of bones that run down your back. (also known as the backbone) Well, it is not actually a bone it is made up of pieces of vertebrae, but I think we can make an exception. The spin connects the skull, it also connects the ribcage which connects the arms and legs. Next after the spine is the ribcage. There are 33 bones in the spine. The ribcage is the group of bones that are in your chest, forming a protective cage around the heart, lungs etc. There are 24 bones in the spine. One in every 20 people has 25 ribs.
Minor parts
The skull is one of the minor part in the Skeletal System. It is the bone that is in your head. It protects the brain and parts of the eyes and ears. It is not actually one bone, it is made up of 22 discs. They are complete circles at the top of the skull, but become doughnut shaped to leave room for your brain.