Appendix - Location, Function, and Facts

Introduction:

An appendix is a finger-like small tube that is present at the junction of the large and small intestine. It is also known as the vermiform appendix, vermix, vermiform process, or the cecal appendix. The term vermiform is derived from the Latin word meaning worm-shaped. The appendix is a hollow tube that is closed at one end and attached to the cecum at the other end. The cecum is a pouch-like part of the large intestine.

Where Is the Appendix Located?

The human appendix is 3.5 to four inches in length but can range from 2 to 13 inches. The diameter of the appendix measures 0.24 inches. Normally, the appendix is located in the lower right abdomen. The point where the appendix is located is called McBurney's point. The appendix develops during the fifth month of intrauterine life. The hollow cavity of the appendix is narrower where it joins the cecum and a little broader at its closed end.

The free end of the appendix varies in position based on its relationship to the ileum, cecum, or pelvis. The positions include pre-ileal, post-ileal, sub-ileal, pelvic, subcecal, paracecal, and retrocecal. The most common position is retrocecal. The artery supplying the appendix is the appendicular artery which is derived from the ileocolic artery, a branch of the superior mesenteric artery. The venous drainage is through the appendicular vein. The nerve supply for the appendix is through the ileocolic branch of the superior mesenteric plexus. Ileocolic lymph nodes are the place where the lymph from the appendix drains.

Why Is the Appendix Considered to Be a Vestigial Organ?

An appendix is a vestigial organ, meaning that it has lost all or most of its original function through evolution. The function of the appendix was considered to be digesting cellulose. As humans cannot digest more than a certain amount of cellulose, the appendix's function is lost. Therefore, the removal of the organ after infancy does not cause any harm, and it is considered vestigial.

What Are the Variations in the Location of the Appendix?

Usually, the appendix is located in the lower right abdomen. In identical twins, sometimes, the appendix shows a variation of position. Congenitally, the appendix is present in the lower left abdomen instead of the right. Intestinal malrotation is another reason the appendix is dislocated to the left side. In some cases, the location of the tip of the appendix varies. In very rare cases, the appendix is absent.

What Is the Function of the Appendix?

The exact function of the appendix is not known. During the early stages of development, the appendix functioned as a lymphoid organ assisting with the B lymphocytes maturation and IgA antibodies production modulating the immune reactions in the digestive system. The appendix is a storehouse for good bacteria, which helps restore the digestive system's function after an illness like diarrhea, which eradicates the normal bacterial flora. The appendix acts as a site for the production of endocrine cells contributing to the biological control mechanism maintaining homeostasis. Some scientists say that the appendix is gradually disappearing over the period of evolution.

What Is Appendicitis?

The appendix has muscular walls that can expel the mucous secretions of the appendix walls or any other contents that have entered the appendix into the cecum. If anything blocks the appendix from expelling the contents, appendicitis occurs. Appendicitis is the inflammation of the appendix. Blockage of the appendix results in appendicitis which causes painful pressure in the abdomen. Appendicitis starts as pain in the belly button area and moves to the lower right part of the abdomen. The pain worsens during coughing, sneezing, deep breathing, or movements. The other symptoms of appendicitis include nausea, vomiting, low-grade fever, and loss of appetite.

Appendicitis can be acute or chronic. Acute appendicitis is a sudden and severe form of appendicitis. It commonly affects children and young adults between the ages of 10 and 30. It is more common in males. Pain is sudden and gradually increases within 24 hours and requires immediate treatment. It is always treated as an emergency. Without treatment, the appendix can rupture, pushing the fecal matter and bacteria to rupture into the abdominal cavity resulting in complications like peritonitis (infection and inflammation of the abdominal cavity) and abscess of the appendix. Chronic appendicitis is less common than acute appendicitis. Appendicitis in pregnancy is also most common and requires surgery in pregnant women.

How Can We Diagnose and Treat Appendicitis?

Appendicitis is usually diagnosed by physical examination by applying pressure to the lower abdominal area. The most common treatment for appendicitis is an appendectomy, the surgical removal of the appendix. This is one of the most common surgeries for abdominal pain. First, antibiotics are given to reduce the infection, and the procedure is done under general anesthesia. Minimally invasive laparoscopy or open surgery is used to remove the appendix. In open surgery, a large single cut is made in the abdomen, and the appendix is removed. Open surgery is done when the access is difficult or the appendix is burst. In laparoscopy, several small cuts are made through which surgical tools are inserted, and the appendix is removed. Laparoscopy has a quicker recovery rate with minimal pain. There is no way to prevent appendicitis.

Conclusion:

The appendix is considered a vestigial organ, but recently, it has been believed that it has functions in storing the gut's beneficial bacteria. The most common appendix disease is appendicitis, a medical emergency that needs the removal of the appendix. Luckily, removing the appendix has no impact, and the patient can lead an everyday life.