Arthroscopy joint by a portal on the outer border of the patella. It is not clear if these examinations were of deceased or of living patients. Pioneering work began as early as the 1920s with the work of Eugen Bircher. He published several papers in the 1920s about his use of arthroscopy of the knee for diagnostic purposes. After diagnosing torn tissue, he used open surgery to remove or repair the damaged tissue. Initially, he used an electric Jacobaeus thoracolaparoscope for his diagnostic procedures, which produced a dim view of the joint. Later, he developed a double-contrast approach to improve visibility.
Composition of the human body viewed on an atomic and molecular scale as shown in this article. The estimated gross molecular contents of a typical 20-micrometre human cell is as follows: Body composition can also be expressed in terms of various types of material, such as: There are many species of bacteria and other microorganisms that live on or inside the healthy human body. In fact, 90% of the cells in (or on) a human body are microbes, by number (much less by mass or volume). Some of these symbionts are necessary for our health. Those that neither help nor harm humans are called commensal