An engaging writing style and meticulous attention to students' learning needs have continually set Human Anatomy and Physiology apart. Now the new Fourth Edition goes even further to engage students by incorporating many new features, such as a free Study Partner CD-ROM, a website, student study tips, and enhanced pedagogy and art program. Used by more than half a million students, this market-leading text is designed to meet the diverse and changing needs of today's students and instructors. Based on their input, the fourth edition integrates numerous new pedagogical featuresstudent study tips, chapter introductions, technology links, a new digital art program, and an interactive Study Partner CD-ROMas well as new teaching tools such as the Instructor Presentation CD-ROM, computerized test bank, and histology slides. At the same time, the fourth edition covers the latest scientific research, including information on the causes of obesity, the impact of two BRACA genes on invasive breast cancer, and the role of P. Aeruginosa in cystic fibrosis.