Picture of the Appendix

Human Anatomy

Picture of Appendix
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Front View of the Appendix

The appendix sits at the junction of the small intestine and large intestine. It’s a thin tube about four inches long. Normally, the appendix sits in the lower right abdomen.

The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past. Surgical removal of the appendix causes no observable health problems.

Appendix Conditions

  • Appendicitis: For unclear reasons, the appendix often becomes inflamed, infected, and can rupture. This causes severe pain in the right lower part of the belly, along with nausea and vomiting.
  • Tumors of the appendix: Carcinoid tumors secrete chemicals that cause periodic flushing, wheezing, and diarrhea. Epithelial tumors are growths in the appendix that can be benign or cancerous. Appendix tumors are rare.

Appendix Tests

  • Medical examination: The original test for appendicitis, a simple examination of the belly remains important in making the diagnosis. Changes in the abdominal exam help doctors tell if appendicitis is progressing, as well.
  • CT scan (computed tomography): A CT scanner uses X-rays and a computer to create detailed images. In appendicitis, CT scans can show the inflamed appendix, and whether it has ruptured.
  • Ultrasound: An ultrasound uses sound waves to detect signs of appendicitis, such as a swollen appendix.
  • Complete blood count (CBC): An increased number of white blood cells -- a sign of infection and inflammation -- are often seen on blood tests during appendicitis.
  • Other imaging tests: When a rare tumor of the appendix is suspected, imaging exams may locate it. These include magnetic resonance imaging (MRI), positron emission tomography (PET), and CT scans.

Appendix Treatment

  • Appendectomy: Surgery is the only treatment for appendicitis. The doctor may use the traditional technique (one large cut) or laparoscopy (several small cuts and using a camera to see inside). Surgery is also needed to remove tumors of the appendix. If the tumor is large, it may require more aggressive surgery with removal of part of the colon.
  • Antibiotics: While the diagnosis is in question, antibiotics treat any potential infection that might be causing the symptoms. In general, antibiotics alone cannot effectively treat appendicitis.
WebMD Image Collection Reviewed by Carol DerSarkissian on February 18, 2017

Sources

SOURCES
Netter F, Atlas of Human Anatomy, 3rd edition, Saunders, 2002.
Young B, Wheater’s Functional Histology, 4th edition, Churchill Livingstone, 2000.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Randal Bollinger R, Journal of Theoretical Biology, 2007; vol. 249: pp. 826-831.
Wagner JM, JAMA, 1996; vol. 276: pp. 1589-1594.
Connor SJ, Diseases of the Colon & Rectum, 1998; vol. 41: pp. 75-80.
The New England Journal of Medicine. http://content.nejm.org/cgi/content/abstract/317/27/1699
Emedicine: Carcinoid Tumor.

© 2017 WebMD, LLC. All rights reserved.