This book is part of a book series called The Human Body in Focus .

There are 24 pages in this book. This book was published 2014 by Child's World .

Susan H. Gray holds bachelor's and master's degrees in zoology from the University of Arkansas in Fayetteville. She has taught classes in general biology, human anatomy, and physiology. She has also worked as a freshwater biologist and scientific illustrator. In her twenty years as a writer, Susan H. Gray has covered many topics and written a variety of science books for children.