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The Human Body: The Appendix

By Becky Stewart

Posted on 2020-10-27

I have a young friend who lives in southern Colorado and is learning mostly at home during the COVID-19 pandemic. Like me, he is endlessly curious, so I offered to help him learn about science topics of his choice. (I also knew I could mine his curiosity for blog post topics, so it’s a win-win.) 

The first thing my young friend wanted to learn about was the appendix, a body part he no longer possesses. Most people only notice they have an appendix when it becomes infected. This was the case with my young friend, who needed to have his removed in a hurry because it burst (or as he likes to say, “It exploded!”). An appendectomy (an operation to remove the appendix) is a relatively common surgery that can be done in a short amount of time. I found this training video for surgeons, demonstrating the surgery on a foam model, and we watched it together. My young friend’s surgeon put the incision in his navel, so the scar will be much less noticeable as he grows.

For many years, it was believed that the appendix was a vestigial part—something that served no real purpose. Recently, however, scientists have begun to suspect that it might be a reservoir for good gut bacteria. In the days before good nutrition was widespread, it would have been necessary to repopulate the gut with good bacteria after a bout with food poisoning or diarrhea. A ready supply near the junction of the small intestine and large intestine, in the appendix, would have been an evolutionary advantage.

Although researchers may find that the appendix continues to have a role in our digestive systems, other parts have been shown to no longer serve a purpose in the human body. Many of these vestigial parts lost their relevance as we evolved from our tree-dwelling primate ancestors to hairless, upright, ground-dwelling humans. Other common vestigial parts (some of which are starting to disappear from the reproductive record) are muscles to move the outer ear, our tail bones, and wisdom teeth.

Luckily for humans, there are other body parts they can live without. Our built-in symmetry creates some paired organs, like the lungs, kidneys, eyes, and ears. If one of the pair stops working for some reason, we can manage with just the remaining one. The two halves of the brain can also learn to compensate for each other, to a certain extent. Humans can manage without certain unpaired organs, too, like the spleen, the gallbladder, and the stomach, although there may be quality-of-life issues.

My young friend has already expressed further interest in the nervous system and the heart, so stay tuned for more human body information.

All students learn more when their interests and experiences drive their learning. Online learning may have significant drawbacks, but in my experience, it is leaving more time for students to pursue their own interests. Many of them also now have the means to do that exploration, with access to district-provided tablets and available WiFi. I encourage everyone to find ways to bring out those interests in your budding scientists.

Becky Stewart 2019Becky Stewart is a geologist by training and a writer by avocation. She has worked for scientific and educational publishers and is currently a scientific copywriter for a laboratory informatics consulting firm. She enjoys spending time in nature, including in her own garden, which has more and less wild phases depending on the season. Additional hobbies include cooking, woodworking, and minor home improvements.

Biology Life Science Middle School High School

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