The appendix is a small, finger-like pouch that is located at the inferior end of the cecum, at the junction of the small and large intestine. This Bodytomy write-up provides detailed information on the location of appendix in the human body, along with the reasons behind the inflammation of this anatomical structure.
Did You Know?
The appendix is considered to be a vestigial structure, as it doesn’t have any function in the digestive process. However, it is believed that it might play a role in maintaining the microbial flora of the gut.
The vermiform appendix is a narrow, worm-like appendage or pouch that is normally located on the right lower quadrant of the abdomen. However, it would be located on the left lower quadrant of the abdomen in case of people affected by situs inversus. Situs inversus is a congenital condition wherein the location of the visceral organs is reversed. This means that the visceral organs that are normally located on the right side would be located on the left side. The location could also differ in case of midgut or intestinal malrotation, a congenital condition which is characterized by the abnormal development of the intestines while a fetus is in the uterus.
Studies have revealed that the base of the appendix is always attached to the cecum, but the location of the tip of this structure could vary. Mostly, the tip can be found in the pelvic or retrocecal region, but it some cases, the tip might be present in the preileal, subcaecal, and postileal regions.
Location of the Appendix in the Digestive System
Closed at one end and attached at the other end to the cecum, the appendix is usually situated around 2 centimeters below the ileocecul junction, which in turn is the place where the ileum from the small intestine and the cecum from the colon come together.
Ileum is the terminal portion of the small intestine that extends from the jejunum (part of the small intestine that lies between the duodenum and the ileum) to the cecum (cavity in which the large intestine begins and into which the ileum opens).
The term ‘McBurney’s point’ refers to the point over the right section of the abdomen that is one-third of the distance from the anterior superior iliac spine (a bony projection of the iliac bone) to the umbilicus (navel). It corresponds to the common location of base of the appendix, where it is attached to the cecum.
Appendix and the Large Intestine
The term ‘taeniae coli’ refers to the three narrow, longitudinal bands of smooth muscle running along the entire length of the cecum and large intestine. All the three bands converge at the base of the vermiform appendix.
The length of the appendix could be anywhere between 2-20 centimeters. The average length of the appendix is considered to be around 6-10 centimeters, whereas the average width is less than 1.3 centimeters. Just like the gastrointestinal tract, the appendix also has an inner layer called mucosa, along with submucosa, muscularis, and serosa layers that surround it.
Though appendix is believed to be a vestigial structure, it is believed that the masses of lymphoid tissues present in the submucosa might be of immunological value. It is believed that the appendix may act as a safe house for beneficial bacteria, and might restore the balance of microbial flora after an illness. It is believed that it might be exposing the white blood cells to the antigens in the gastrointestinal tract, which in turn might stimulate the production of antibodies. This might help produce an immune response in the gut.
The inner portion of the appendix is called the appendiceal lumen. The appendix produces mucus, which passes through the appendiceal lumen. The muscular walls of the appendix expel the mucous secretions and any of the intestinal contents that might find a way into the appendix and the cecum. Problems arise when the narrow cavity or the opening where the appendix joins the cecum gets blocked. The blockage could occur due to trauma to the abdomen, inflammatory bowel disease (Crohn’s disease, ulcerative colitis), infection in the gastrointestinal tract, hardened stool, etc. As a result of the blockage, the mucus backs up in the appendiceal lumen, which causes bacteria to multiply. This might cause appendicitis, which is a condition that is characterized by the inflammation of the appendix.
More often than not, pain is felt at the McBurney’s point. However, the location of pain might vary, depending on the anatomical variations in the location of the appendix. The common symptoms of this condition include:
➠ Abdominal pain that is felt near the navel and then moves lower and to the right
➠ Sudden onset of excruciating pain
➠ Pain that worsens while taking deep breaths
➠ Pain that worsens with coughing, sneezing, or sudden/jerky movements
➠ Tenderness in the lower right abdomen
➠ Loss of appetite
➠ Low-grade fever
➠ Abdominal swelling
More often than not, the surgical removal of appendix is suggested as a treatment for appendicitis. This surgery is referred to as appendectomy. The reason behind performing this surgery is to avoid the complications that are associated with the rupturing of the inflamed appendix. Sepsis is a life-threatening complication that can arise due to the rupturing of the appendix. The leakage of the contents of the inflamed appendix can cause a generalized infection in the abdomen (peritonitis).
If the appendix has ruptured, the abdomen is cleaned with sterile, warm water, and the infected fluids or the contents that may have spilled out are drained out through a tube. The appendix can be removed through an open surgery or a laparoscopic surgery.
On a concluding note, the appendix is believed to be a remnant of a structure that might have had a function in our ancestors, but has lost its function due to evolutionary change. Determining its exact location is of utmost importance during an appendectomy. As it has no digestive function, its surgical removal is the best option for preventing the complications that could arise due to inflammation and rupturing of the appendix.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.