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vermiform appendix anatomy

#appendix #vermiformappendix #appendixanatomy The appendix (or vermiform appendix; also cecal [or caecal] appendix; vermix; or vermiform process) is a finger-like, blind-ended tube connected to the cecum, from which it develops in the embryo. The cecum is a pouch-like structure of the colon, located at the junction of the small and the large intestines. The term "vermiform" comes from Latin and means "worm-shaped." The appendix used to be considered a vestigial organ, but this view has changed over the past decades.recent research suggests that the appendix may serve an important purpose. In particular, it may serve as a reservoir for beneficial gut bacteria. The human appendix averages 9 cm in length but can range from 5 to 35 cm. The diameter of the appendix is 6 mm and more than 6 mm is considered a thickened or inflamed appendix. The longest appendix ever removed was 26 cm long. The appendix is usually located in the lower right quadrant of the abdomen, near the right hip bone. The base of the appendix is located 2 cm beneath the ileocecal valve that separates the large intestine from the small intestine. Its position within the abdomen corresponds to a point on the surface known as McBurney's point. The appendix is connected to the mesentery in the lower region of the ileum, by a short region of the mesocolon known as the mesoappendix. Although it has been long accepted that the immune tissue surrounding the appendix and elsewhere in the gut—called gut-associated lymphoid tissue—carries out a number of important functions, explanations were lacking for the distinctive shape of the appendix and its apparent lack of specific importance and function as judged by an absence of side effects following its removal. Therefore, the notion that the appendix is only vestigial became widely held. William Parker, Randy Bollinger, and colleagues at Duke University proposed in 2007 that the appendix serves as a haven for useful bacteria when illness flushes the bacteria from the rest of the intestines.This proposition is based on an understanding that emerged by the early 2000s of how the immune system supports the growth of beneficial intestinal bacteria, in combination with many well-known features of the appendix, including its architecture, its location just below the normal one-way flow of food and germs in the large intestine, and its association with copious amounts of immune tissue. Research performed at Winthrop–University Hospital showed that individuals without an appendix were four times as likely to have a recurrence of Clostridium difficile colitis. The appendix, therefore, may act as a "safe house" for beneficial bacteria. This reservoir of bacteria could then serve to repopulate the gut flora in the digestive system following a bout of dysentery or cholera or to boost it following a milder gastrointestinal illness Immune and lymphatic system Edit The appendix has been identified as an important component of mammalian mucosal immune function, particularly B cell-mediated immune responses and extrathymically derived T cells. This structure helps in the proper movement and removal of waste matter in the digestive system, contains lymphatic vessels that regulate pathogens, and lastly, might even produce early defences that prevent deadly diseases. Additionally, it is thought that this may provide more immune defences from invading pathogens and getting the lymphatic system's B and T cells to fight the viruses and bacteria that infect that portion of the bowel and training them so that immune responses are targeted and more able to reliably and less dangerously fight off pathogens. In addition, there are different immune cells called innate lymphoid cells that function in the gut in order to help the appendix maintain digestive health. Appendicitis is a condition characterized by inflammation of the appendix. Pain often begins in the center of the abdomen, corresponding to the appendix's development as part of the embryonic midgut. This pain is typically a dull, poorly localized, visceral pain. As the inflammation progresses, the pain begins to localize more clearly to the right lower quadrant, as the peritoneum becomes inflamed. This peritoneal inflammation, or peritonitis, results in rebound tenderness (pain upon removal of pressure rather than application of pressure). In particular, it presents at McBurney's point, 1/3 of the way along a line drawn from the anterior superior iliac spine to the umbilicus. Typically, point (skin) pain is not present until the parietal peritoneum is inflamed, as well. Fever and an immune system response are also characteristic of appendicitis. Appendicitis usually requires the removal of the inflamed appendix, in an appendectomy either by laparotomy or laparoscopy. Untreated, the appendix may rupture, leading to peritonitis, followed by shock, and, if still untreated, death