And that's actually easy to remember because both of these begin with the letter M. Now if we form the cardiac muscle and the smooth muscle from the mesoderm, then that implies the entire cardiovascular system which consists of the heart that is formed from cardiac muscle and the blood vessels and blood are also formed from the mesoderm. So the cardiovascular system, the circulatory system is found, is formed from the mesoderm. Now blood is a connective tissue and the mesoderm not only forms this connective tissue, it also forms other connective tissue. So what other connective tissue do we have in our body? Well, bone, bone is a type of connective tissue and so the skeletal system is also formed from the mesoderm germ layer. And that makes sense because it is located in between these two layers.