Lesson 54, Skeletons We are all familiar with skeletons composed of bones; every
Halloween, pictures of the human skeleton adorn many houses. But there
are also skeletons that aren't made of bones. In this Lesson, we'll explore the different types of skeletons. Then
we'll introduce the structure and roles of bone and see how bones are
assembled to form a skeleton. We'll also look at how muscles and the
skeleton work together to cause movement.