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How do scars form? - Sarthak Sinha


11,986 Questions Answered

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It’s hard to escape childhood without racking up a few scars. Why do these leftover reminders of a painful cut or crash look different from the rest of our skin? And why do they stick around for so long after the incident that caused them? Sarthak Sinha explains how scars form.

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The music track in this lesson is "Air Hockey Saloon" by Chris Zabriskie. It is Creative Commons. The track has been looped and edited.

In this lesson, we tried to demystify 3 important questions related to the biology behind scaring. These were: 1) What is a scar? 2) How it’s formed and 3) Where else in the body can it form beyond skin? With these serving as a foundation, you might now be left wondering how physicians actually address this issue in a clinical setting. Well, the answer to that question isn’t so universal.

To understand the complexity behind scar management, we must first recognize that there are different types of scars to begin with. In the skin, a ‘hypertrophic scar’ is the name given to scars that don’t expand beyond the boundaries of the original wound. A second type of scar, know as ‘keloid scars’, keeps growing even after the wound has completely healed and can extend well beyond the boundaries of the initial wound. Learn more about scars from Columbia University Dermatology. Even though both types of scar occur from an abundance of deposited collagen, the characteristics of these two scars can be very different and therefore can require different clinical approaches to manage them. How would a physician manage scarring? Visit John Hopkins Medicine Health Library to find out.

Another appealing (and perhaps less biological) aspect of scaring comes from its history and the ways in which it was previously used for. Although the insights we possess in understanding this process has been fairly recent, the observation that wound healing leaves behind a long lasting mark was observed and used centuries ago. Read the BBC article: Why some people want facial scars and gain some insight into the cultural importance of scarification.

One technique, which exploits this, is known as human branding. Similar to permanent tattoos, the goal of branding is to leave a permanent mark on the body. This is achieved by placing a hot stainless steel rod with an intention to wound and leave behind a permanent mark. While the ancient Romans used this technique to brand run away slaves, the same technique is used today to mark livestock with tags, which makes them easier to identify. To read more about this technique gaining popularity, be sure to read a recent report published last year. 

Finally, if the concept of fibrosis and the formation of excessive connective tissue in other parts of the body was something that resonated with you, be sure to explore these three selected conditions, all are a result of fibrosis:

1) Cardiac fibrosis – Resulting from abnormal proliferation of cardiac fibroblasts.
2) Cirrhosis – Resulting from healthy liver tissue being plagued by fibrosis.
3) Arthrofibrosis – Resulting from fibrosis in joints such as ankles and shoulders.

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TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Sarthak Sinha
  • Animator Noel Wong, Mark Storer, Henry Chung, Alexandra Kogl
  • Artist Ieuan Protheroe, Ricky Earl
  • Script Editor Alex Gendler
  • Narrator Addison Anderson

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