What is are skeleton made of?

The skeleton is a system of bones connected throughout the human body. Like said in the previous sentence, it is made up of bones. Over the bones, are layers of muscle and tissue. Then organs like the brain, the heart, lungs, liver, intestines, kidneys, pancreas, appendix, gull bladder, bowels, bladder, female reproductive organs or male organs. I don't think I missed anything :)