Stickmen's Guide to Your Mighty Muscles and Bones

Stickmen's Guide to Your Mighty Muscles and Bones — page 3
Introduction Although your body seems very complicated it all begins to make sense if you think of it in terms of systems each with its own task to do Some systems such as the nervous system the body’s communication system extend throughout the body It is the task of the skeleton the body’s framework of bones to protect you and keep you upright The skeleton also works with muscles which give your body the ability to move Skeleton The skeleton is the part of the body that may last the longest after a person dies That’s because the bones are made from tough minerals that don’t quickly rot away Altogether over 100 billion people have lived on Earth so far That means there could be 100 billion skeletons lying around Fortunately most do crumble into dust eventually Lucy The world’s most famous skeleton is about 3 2 million years old It’s called Lucy and is the skeleton of a small ancestor of humans called an australopithecine It was found in Ethiopia in 1974 Its shape shows that even this long ago our ancestors walked upright on two feet 6