3 Continuing Education Units (CEU) - The skeletal system has many important functions. Our bones are strong enough to bear weight, yet light enough to allow for flexible movement. In addition, many of our bones provide protection for our internal organs. For example, our skull protects our brain, and our rib cage protects our heart, kidneys, and other organs. Our bones also store materials our body needs, such as calcium, magnesium, phosphorus, and bone marrow.