This book will be of interest to anyone who wants to use ultrasound to understand human physiology both in the clinical setting and the classroom. Tremendous advances in ultrasound technology have resulted in portable ultrasound systems that are easy to use, produce excellent images, and are affordable with quality hand-held and laptop-sized systems costing between $2K and $20K. These systems are now being used at the patient bedside or point of care by almost all medical and surgical specialities from primary care to orthopaedic surgery. These portable systems, especially the hand-held devices, are now being called the stethoscopes of the 21st century and will likely be used by many that are presently using stethoscopes including physicians, nurses, physician assistants, medics and other health professionals. Ultrasound began to be used in medical student education in the 1990s and is steadily becoming a common teaching tool for courses like anatomy and physiology.