## Fatal mistake The appendix is a worm-like organ measuring 8–10 cm, which is an appendage of the cecum. At the beginning of the twentieth century, it was recognized as a rudimentary organ capable of causing appendicitis. Therefore, in some countries, such as Germany and the United States, infants had it removed after birth. This practice changed when people realized that babies with removed appendixes could not digest breast milk, became more ill and fell behind in development. ## Valuable container Immunologists conducted numerous studies that concluded that the appendix is an extremely important element of the human immune system. First, it is a real reservoir for beneficial bacteria. The entrance opening of the appendix is very narrow (1–2 mm), and the intestinal contents do not get into the appendix. Because of this, beneficial microorganisms accumulate and are preserved in the appendix, contributing to normal digestion and immunoglobulin production. For example, when beneficial microflora is washed out of the intestines in a case of diarrhea, the appendix takes over the task of producing beneficial bacteria and helps restore the digestive system after the disease. This repopulates the intestines with beneficial microorganisms. Scientists have also concluded that the walls of the appendix contain a significant amount of lymphoid tissue, which provides immune protection. The tissue produces lymphocytes and plasma cells that fight pathogens and viruses. ## Conclusion There is no doubt that the appendix is an important organ of our immune system. Nevertheless, scientists continue to study it, and perhaps in the near future, we will learn about its other functions. But, of course, in the case of appendicitis, acute inflammation of the appendix, the appendix should be removed immediately as there is no way to reverse the process.