My Hero Academic: Quirk Science!
by Hannah Kissinger
If you could have one superpower, what would it be?
I don’t know about you, but I can never come up with an answer to this question. Honestly, superpowers used to be a very one dimensional concept for me. A regular human is exposed to extraordinary circumstances and is then capable of inhuman feats. Superpowers that were meant to be overpowered- with few (if any) weaknesses- had a tendency to become stale quickly.
AND to pick just ONE superpower without knowing how it works is an unbelievably difficult task.
Maybe I am too much of a realist?
Luckily, Kohei Horikoshi, the author of My Hero Academia, has created a universe where many superpowers, or ‘quirks,’ can be explained by science!
In the My Hero Academia universe, 80% of the world’s population is born with a quirk. Quirks are inheritable from one or both of your parents... and children born with a combination of traits are typically far more powerful than their parents (with equally powerful drawbacks that is).
While there are articles that examine the quirks of My Hero academia, very few go into great detail regarding their biological feasibility...
So I welcome you to ‘Quirk Science!’
A blog series where I apply various scientific concepts to explain the impossible~
Let’s get to it!
PLUS ULTRA!!!
Apocrine- Large sweat glands responsible for fatty secretions
Eccrine- Small sweat glands responsible for skin maintenance and thermoregulation
Secretion- The process where substances are made and released by a cell, gland, or organ for an organismal function or elimination
Electrolytes- Necessary for our bodies to function: sodium, potassium, calcium, etc.
Water soluble- Dissolvable in water
Solute- A substance dissolved in a liquid to form a solution
Stress- Strain (mentally and/or physically)
Thermoregulation- The process to maintain core internal body temperature
Homeostasis- Stable internal body conditions
Adrenaline- A hormone secreted by the adrenal medulla glands
Autonomic nervous system- The mostly ‘involuntary’ portion of the nervous system
Sympathetic nervous system- The “fight or flight” response
Parasympathetic nervous system- The “rest and digest” response
Anhydrosis/hypohidrosis- Physical condition where individuals are unable to sweat in small or large areas of their bodies
Humans are always sweating. The amount we sweat can vary based on our emotional and physical states. When our bodies experience these states of stress, a human can sweat between 0.8 to 1.4 liters an hour. This amount could fill ~1.5 to ~3 single serving soda bottles!
We have two major types of sweat glands: apocrine and eccrine.
Large apocrine sweat glands are associated with hair follicles of the armpits and groin region. Initially odorless, the fatty secretions produced by these glands cause body odor when they come into contact with skin bacteria (Eeww!).
Eccrine sweat glands, on the other hand, are found everywhere! These tiny sweat glands have two important functions: skin maintenance and thermoregulation. Since Bakugo Katsuki’s quirk is localized to the palms of his hands (as far as we know), the nitroglycerin he uses to create explosions is likely secreted via his eccrine sweat glands.
My Hero Academia lore implies that he is able to ‘control’ how much he sweats. Humans, however, are fundamentally incapable of controlling specific sweat glands... beyond rolling anti-perspirant onto our skin that is.
Scientifically, there are two possible explanations for Bakugo’s sweat ‘control’:
He uses his emotions as a tool to sweat more.
Overuse of his quirk may cause his sweat glands to switch off.
Now if Bakugo’s emotions are actually the driver of his quirk, this may help to clarify why he is so ill tempered. Anger is a powerful emotion, capable of increasing an individual’s heart rate and blood pressure. It does this by triggering the release of adrenaline, a hormone, into the bloodstream from (quite fittingly) the adrenal medulla glands. Adrenaline then goes on to impact the (mostly) involuntary portion of the body’s nervous system -aka- the autonomic nervous system. The autonomic nervous system is divided into two systems: the sympathetic and parasympathetic divisions. Complementary to one another, the sympathetic division activates the “fight or flight” response while the parasympathetic division activates the “rest and digest” response. Anger provokes the “fight” portion of the sympathetic response and cause...you guessed it...increased sweat production! Bakugo could- quite literally- be using his anger as fuel for his explosions…
Sweat secreted from eccrine glands is composed of 99% water, electrolytes, and other water-soluble substances. The most concentrated solute in sweat is sodium chloride (or NaCl, if you were ever wondering why your sweat was so salty!). Sweat also contains small concentrations of potassium, lactic acid, glucose, and nitrogen- just to name a few. As the sweat evaporates from our skin, it removes excess body heat. This ‘evaporative cooling’ allows us to maintain homeostasis, or steady internal conditions.
There are situations where individuals are unable to sweat in small or large areas of their bodies. This condition, called anhidrosis (or hypohidrosis), is the result of extreme dehydration. As Bakugo’s quirk relies heavily on sweat production, he is at high risk of dehydration if he doesn’t drink enough fluids and electrolytes in replacement. In support of this theory, whenever Bakugo overuses his quirk, he is shown to develop muscle cramps in his arms and shoulders- which are symptoms of dehydration. Coincidence? I think not.
So, from an anatomical and physiological standpoint… the mechanism of Bakugo’s quirk is theoretically possible. Could a regular human have sweaty palms by triggering their “fight or flight” response? Sure. Do we want to have the potential stress and other symptoms associated with it? Probably not. Though, Bakugo might not have a choice in the matter if he aims to be the number one hero!
TO SUMMARIZE!
Bakugo’s quirk affects the eccrine sweat glands in the palms of his hands.
Bakugo’s explosive anger may help him to ‘control’ the amount he sweats by activating the “fight” response of the sympathetic nervous system.
The drawback to Bakugo’s quirk is likely caused by dehydration.
SOURCES:
Robinson S. & Robinson A.H. (1954). Chemical Composition of Sweat. Physiological Reviews, 34(2), 202-220. [LINK]
Sato K., Kang W.H., Saga K., Sato K.T. (1989). Biology of sweat glands and their disorders I. Normal sweat gland function. Journal of the American Academy of Dermatology. 20(4), 537-563. [LINK]
Bernhardt G. Cracking the Code on Sweat Rates. Active.com. [LINK]
Cui, C. Y., & Schlessinger, D. (2015). Eccrine sweat gland development and sweat secretion. Experimental dermatology, 24(9), 644-50. [LINK]
Hu, Y. & Converse, C. & Lyons, M.C. & Hsu, W. (2017). Neural control of sweat secretion: A review. The British journal of dermatology. 178. 10.1111/bjd.15808. [LINK]
You and your hormones. Adrenaline. Society for Endocrinology. [LINK]
Hormone Health Network. What is Adrenaline? Endocrine Society. [LINK]
Backyard Brains. Experiment: Activate your Sympathetic Nervous System. Backyard Brains. [LINK]
Lupis, S. B., Lerman, M., & Wolf, J. M. (2014). Anger responses to psychosocial stress predict heart rate and cortisol stress responses in men but not women. Psychoneuroendocrinology, 49, 84-95. [LINK]
International Hyperhidrosis Society. Anhidrosis (Inability to sweat). International Hyperhidrosis Society. [LINK]
Sato K., Kang W.H., Saga K., Sato K.T. (1989). Biology of sweat glands and their disorders. II. Disorders of sweat gland function. Journal of the American Academy of Dermatology. 20(5), 713-726. [LINK]
About the Author
Hannah Kissinger is a PhD student in Microbiology at the University of California, Riverside. With a BS in biomedical sciences and an MHS in medical laboratory sciences, she is now branching out into environmental microbial ecology. A true appreciator of storytelling- she can't even count how many Disney movies, anime, or K-dramas she has seen. In her free time, she likes reading webtoons and learning new cosplay crafting techniques.
Instagram: @invisicap
Twitter: @HJKissinger