Sunday, December 9, 2007

A Case Study of the Vestigial Appendix

You wake up one morning with a slight dull pain in your abdomen. You rest your hands on your stomach pressing down around your belly button. The pain increases slightly and you notice that it worsens as you move your hands over your belly towards the right side of your hip. You brush it off as a case of indigestion from the leftover meatloaf and potatoes your roommate threw together the night before, and you head off to your university classes. By the end of the day, your stomach pain and bloating has worsened. To make matters worse, you feel weak because you could not get yourself to eat at all during the day. You have to go to one last class, however, you are feeling very nauseous and starting to perspire. You run to the bathroom and hope that no one heard you vomiting as you hovered over the Porcelain toilet. At this point, you realize that you feel too awful for this to be an ordinary occurrence and you phone your roommate to take you to the hospital.

After a long night of tests in the emergency room, the doctor informs you that you have appendicitis. You will have to have surgery to remove your appendix because there is a possibility that you could die if it bursts. All you manage to extract from the conversation with the doctor is the possibility that you could die and that you have some sort of reference section at the end of your intestine. Your mind is racing and you are confused from the spike in fever. Thankfully, the nurse comes in and explains to you what is occurring in detail.

Your appendix is a small pouch-like structure attached to the beginning of your large intestine (1). The actual cause of appendicitis is not known, however, it is commonly believed that the bacterial infection is a result of trapped fecal matter in the appendix (2). The infected appendix can worsen and abscess, exploding inside your peritoneal cavity (where your intestines are located) (3). The bacteria spread throughout, causing multiple organ failure and killing the patient (4).

You are worried at this point and are thinking that your life might be drastically affected by the loss of a digestive structure, but you need the appendectomy to survive. The nurse ensures you that most patients do not notice any difference in digestion after an appendectomy since your appendix is a redundant structure (5). The appendix is a vestigial organ; meaning the original function was lost with human evolution (6). It was originally thought to be the organ responsible for digesting cellulose, as seen in other herbivorous primates sharing commons ancestors with humans (7).

All experts in the medical community do not share the opinion that the appendix is a vestigial structure. Others believe that the appendix has an immunological function as an organ where antibodies are produced (8). This theory does not have strong supporting evidence, as the appendix would less likely become infected if it were a center for antibody production. Another theory suggests that the appendix is used to store necessary intestinal bacteria (9). Although the appendix may contain important bacteria, patients fail to notice a difference in digestion without an appendix (10). This indicates that the appendix cannot have a substantial role in the digestive system and, therefore, is a structure lacking true function.

Knowing the current information puts your mind at rest and you feel relieved that shortly you will have the source of your pain removed without long term consequences. You are informed that they are ready to take you in for surgery. As you are rolled into the operating room, you whisper into the nurse’s ear one last request. You want to keep your appendix. Here is a picture of what you grew so close to and could not part with:

Your Appendix

You Tube Video:
Surgical Appendectomy (caution graphic details):