I use a Nikon, but several are available. The pros are the very high quality images and archival capability. The only con is the cost. They have the added benefit of being eye-catching. Line drawings also help you to convey key points, although they should be used sparingly.
Several companies specialize in medical and anatomical clip art.
Conversely, you can simply scan drawings from anatomy texts and import them to you document. Finally, a word about printers. All Rights Reserved, Dynamic Chiropractic, 2001.