Following is a transcript of this video; note that errors are possible:
Rohin Francis, MBBS: Yes, today we're ranking organs. I have got a day off and, as you can probably tell from my eyes, I stayed up really late last night watching a lot of TierZoo, and I figured, "Hey I could do that, except much worse."
That's what this is, a definitive tier list of organs, concentrating on the human biome, about which I have some strong feelings so I have just decided to freestyle this. I had some thoughts on the walk over here, but it's off the cuff. I will choose whether I talk about organs or organ systems via a complex combination of random chance and whim.
Now, as with any tier list, people start by saying that this is just their opinion and, "I'm sure there'll be errors." But not on this occasion. These are just straight facts. I am merely a vessel through which the all-knowing organ god speaks and the organ god says that this list is final. There may be some omissions -- we can't cover everything -- but there are no mistakes.
Let's begin. I'll start with one of my favorites, bone. Often thought of as a kind of dead and inert organ, the skeleton not only acts as the only thing preventing us from being a gelatinous mass of blubber rolling around on the floor, but it's also an armored repository for some of our most valuable loot, marrow, where bone cells are formed.
270 bones at birth, but 206 by the time they're fused together. Big ones, tiny ones, all with their own blood supply and beautifully-designed architecture, making them strong yet light. Your entire skeleton is constantly being reabsorbed and redeployed, completely turning over every 7 or 10 years or so.
It's reactive, so squash players and basketball players have the densest, thickest bones, which is good for them, because all of us lose bone mass from about middle age onwards. All bones articulate with other bones except the hyoid, which is here all on its own and hence totally ruining the famous song.
Now, knocking bones down from A tier is the fact that they break easily and take so long to regain HP, the fact that the ankle and the wrist are just appalling bodges. I mean, look at that nonsense. The hands and feet account for over half of all the bones in the body.
Whichever dev implemented this patch needs to be placed in a full-body cast. Unlike most of our primate cousins, we don't even have a penile bone and yet we still call it a boner. Very disappointing, B tier.
Now, talking of tasty, tasty marrow, next up is blood. Oh, you think blood is a tissue, not an organ? Well, not only are you wrong, but you will be our first blood sacrifice to the blood god. The only organ that is a non-Newtonian fluid and magnetically active, it's our window on the workings of the body. Where else can you get so much information about what's going on? There are literally thousands of tests that can be run on just a small bottle of this stuff. Of course, it's so vital we have many idiomatic terms like...
Captain Sisko: Don't get between me and the bloodwine.
Francis: An economy's lifeblood, someone having a sanguine nature, being a red-blooded person, royal bloodlines, the blood of Christ, halal and kosher, drain all the blood, blood brothers, bad blood, blood is thicker than water, and, of course, safe blood.
The first color that cultures name all over the world is red, probably because of the profound effect that seeing blood has on humans. It takes oxygen and nutrients to every cell in the body. It removes all the garbage. It ensures immune cells arrive at areas of need almost immediately. You produce 70 million red blood cells every second. They live about 120 days and yet the total volume of blood in the body is a paltry 5 liters. Truly, blood is a wonderful organ. S...
Sorry, I'm just getting word that heart attacks are actually caused by blood clots. This is new information to me. Apparently platelets just lose their freaking minds when they come into contact with a ruptured cholesterol plaque and decide to block the artery. Total losers.
And what's this? Blood in the veins can spontaneously clot as well in the leg, something called a deep vein thrombosis, which can travel to the lungs and kill you. What causes this appalling thing? Sitting still for a while. What the hell? Oh my God, blood, you're insane. D tier.
Next up, the thymus. This genius, living the goddamn dream. The ancient Greeks observed the thymus, but we only figured out what it was and what it did in the 1960s. Elusive. Enigmatic. I like that. It's part of the immune or, more accurately, the lymphatic system. It's where T cells mature. You've probably heard a bit about T cells this year, but let's not hold that against the little thymus.
Located around here, it's very active in childhood but then starts to gradually disappear in our teens and is completely absorbed by adulthood. In many ways, the thymus is our sense of fun, active, and carefree when we're kids, but replaced by fatty tissue when we grow up.
Thymus, you are spared the horrors of the world today because you made the right decision and noped the f*ck out of there when sh*t got real. Take your deserved place in B tier, thymus. As for your homophonous friend, the thyroid, pretty boring, lazy as hell in millions of people, and just a wild crack fiend in others. No, thyroid, you're E-tier at best.
The pancreas is just a sorry, rubber, Christmas tree-looking sucker that people only care about when it can't be bothered to do one of the few jobs it's tasked with, make some goddamn insulin. Or when it kills people, like Patrick Swayze, because pancreatic cancer has such an atrocious survival rate. The reason being that pancreatic cancer tends to only cause problems once it's too late, like an employee that keeps getting paid, but hasn't turned up to work for 3 years.
No, the pancreatic build is not worth the islet cells it's printed on. A sneaky organ that deserves to be shunned, E tier. But even the pancreas looks like a goddamn saint next to the prostate.
Seriously, bro, what the hell is your problem? You produce prostatic fluid? Oh well, good for you, man. But no matter how much of that orange website your owner watches, that isn't real life, man. Nobody cares about the marginal effect your fluid has on spermatozoa survival.
Prostatic fluid makes the vagina slightly less acidic and hence protects the sperm ever so slightly. But in exchange for this meager benefit, men literally lose the ability to pee. I mean, if you have any sense, you're going to have a maximum of 2 kids in your life. But if you pee like 200,000 times in your life, why is this deemed less important?
Not to mention prostate cancer, which affects almost every man over a certain age. The only reason we don't just whip the pointless lump out is that it's wrapped around some rather important pipes, desperately trying to remain the center of attention like a narcissistic fungus. Prostate, you're an absolute waste, man, F-tier.
The brain. Now, the only organ on this list that actually named itself, I have mixed feelings about the brain. On one hand, it's been responsible for human evolution, and to become the most dominant species on the planet, and all the wonders of human civilization. But on the other hand, people are idiots.
In fact, you could sum up all of the best and worst about the brain in one word, democracy. We landed on the moon, but we also made Cats. If the brain was really so important, how would dozens of people be able to comment on YouTube videos when clearly not in possession of one?
I go days without really ever using my own and nobody seems to notice, but okay. As of right now, the brain is the most complex thing known to humans in the universe. No matter what tech bros say, we are light years away from understanding the brain properly, and that's thrilling. It means that there's so much more to learn.
If the brain was so simple that we could understand it now, it would mean that we would be too simple to understand it anyway. I would go so far as to say that a huge proportion of neuroscience and neurology is just guesswork at the moment. We'll look back on the current era and consider even the most advanced functional MRI scans akin to an ant trying to understand a supercomputer by feeling the heat of its CPU, so surely brain must be top of the pile?
Well, the brain has killed millions of women through history. Now, I'm not talking about the patriarchy. I'm talking about our rapidly-expanding brains, three times bigger, relatively speaking, than our closest cousins, the chimp. A size altogether impractical for women's pelvic canals, which is about the same size as a chimpanzee's despite them being half our height. Biologically, modern humans have a far more perilous route into the world, having to turn twice as opposed to just once or not at all, like other apes, when exiting their mother's womb, increasing the risk of wrapping umbilical cord around their necks and, of course, risking killing their mothers as well, which through history they have done on a regular basis.
As a species, we are now dependent on assistance to perform the most essential of biological functions. Our brains are simply not designed for the modern world either. Our cultural progress has been so rapid -- ironically, because of our brains -- that we're biologically adapted to a very different world to the one we find ourselves in today. Things like motion sickness, violence, cognitive biases, superstition, fear, obesity. So many problems big and small can be traced back to the fact our brains still think we're gatherer hunters on the plains of Africa. S tier. You're right, the female pelvis is a shocker, so I think bones should be knocked down another tier.
Now, if you can nerf an organ and pretty much carry on with your life without much issue, then you're never really going to score higher than a C, and that's where we find the spleen. Now, that's not to say it's not clever. It filters blood. It's got an important role in the immune system, meaning that people who have lost their spleen need to take prophylactic antibiotics.
But my favorite splenic feature is actually its ability to act like a little blood bag and resuscitate the rest of the body in case of sudden blood loss or when diving and in need of some oxygen. I even made a whole video about that. The spleen sits on the C splenic flexure in the tier list.
As for the gallbladder, though, useless as hell and just fills up with stones that get stuck in various places causing pain, inflammation of that other low-tier trash organ, the pancreas, or even life-threatening infection. Get out of my sight.
But just next to the utterly disappointing pancreas and gallbladder is a beast that single-handedly redeems the otherwise sorry abdominal cavity, the goddamn hepatic hulk, the abdominal abomination, the monster of metabolism. It's the liver.
The liver is wild. It metabolizes almost everything you put in your body, no matter how idiotic. It laughs in the face of Gwyneth and her Goop detoxes because it detoxes more in a minute than a lifetime's worth of juice cleanses.
The digestive system sends all the nutrients to this Amazon megafactory that breaks down fat, tucks energy away, churns out dozens of different things such as hormones, clotting factors, proteins, bile.
In fact, nobody even knows how much the liver does, but most textbooks estimate it performs about 500 different roles. 500, and you sozzled drunks just abuse it with alcohol. It's so complicated that no matter what we do, no machine can replicate its function, and the only treatment for a broken liver is a transplant.
Luckily, its powers of regeneration are so incredible we don't need to transplant very often. But even when we do, that is remarkable. You can donate up to 70% of your liver to someone and that chunk will develop into a whole liver, plus yours will grow back into a full liver in a month or two. Are you kidding me? The liver, god-tier.
Remember when we were younger and Neanderthals were these dumb, subhuman idiots whose names we literally used as insults, but then DNA testing found that all Europeans share some Neanderthal DNA and, boom, overnight there were these sophisticated people with personal stories, culture, art, and emotion?
The same shi*t, literal shi*t, has been going on with the gut and the "magical microbiome" that controls everything. Sure. You're telling me that I have got to eat food based on what my gut bacteria will like? I mean, who is in charge here? This is some nightmare from a Dawkins book.
Wheat enslaved humans. It's gone from a random grass to the most dominant plant on the planet with a subservient species of biped that eliminates all its competitors and guarantees it perfect living conditions.
Are the bacteria the ones with the selfish gene that are farming us? Have we been bred by bacteria to offer them food and shelter? Ironically, wheat is now enemy #1 of yoga moms and Celiacs because of its effect in the gut. Glutenati-confirmed.
The stomach, okay, fair play. Anything that produces concentrated hydrochloric acid, fair play, homie. You is a pimp, but the bowels, jeez. Literally, nobody cares. You're a few meters long? Big deal. Get in line behind the circulatory system, nerves, and lymphatics.
Oh, the bowel has a second brain? Get real. Nobody believes that except gastroenterologists, people who voluntarily went into a career looking up people's backsides. Intestines, E tier. Jejunum and duodenum, D, but only because I like the names. Interstitium, get out of here. That's not even an organ. Everybody knows it.
Next, kidneys. More gangsters right here. What do the kidneys do? Make urine. That's like saying, "What does an engine do?" "Makes smoke." The urine is just incidental. It's a byproduct. The kidneys and the liver form the most badass tag team since Desmond Haynes and Gordon Greenidge opened for the West Indies. That's a niche reference, but those who get it will appreciate it.
Ensuring that your insides maintain those Goldilocks-perfect conditions, the kidneys tightly regulate the pH of your blood with such incredible control that they laugh in the face of alkaline diets. Because no matter what you ingest, your interior acid base status remains remarkably constant.
Each kidney has about a million separate nephrons, each filtering the blood, removing waste and fine-tuning electrolytes. Along with the heart, kidneys regulate blood pressure and even control red blood cell synthesis. They can take an insane punishing and recover. A tier for these bad boys.
The uterus. This is a goddamn sleeper cell, special agent, Charlize Theron badass. Chills out for like 95% of the time until enlisted into action and literally grows a new human, along with another absolute dynamite organ, the placenta.
I know us guys like to think that we're the ones with an organ that can get bigger when called upon, but the uterus goes from the size of a pear to the size of a football, a proper football, a football of pure muscle that is so strong it pushes the aforementioned stupidly big-headed small person out through that narrow birth canal. For being the incubation chamber for every human that has ever lived, the uterus is S-tier, even though it does tend to kind of lose the plot every month or so.
Lungs. Basically, just big balloons. Mucus is by far the most disgusting bodily fluid. Lungs seem very hand-in-glove with COVID-19, and coughing, just a deeply unpleasant human experience, 0 out of 10, would not recommend to ascension AI.
The heart and lungs both require a lot of physics to understand. But while fluid dynamics is just awesome and logical -- all those infernal gas laws, diffusion gradients, and just all that crap -- you can't even see air. Like, who cares?
I will concede that the lungs are fairly important, with gas exchange and all. Actually, gas exchange is pretty cool. No, it's very cool, actually, looking up a blood gas and fiddling with the ventilation set. Okay, it's nice.
The kidneys aren't the only organs that regulate pH. The lungs do it too. If you overdose on something acidic, the lungs blow off carbon dioxide to compensate. If you consume something alkaline, it will retain CO2, so kidneys and lungs combine to provide metabolic and respiratory compensation for exogenous acids and bases.
Any organ that openly mocks quack pots who endorse alkaline diets are okay with me. A tier. Plus, the left lung took a voluntary debuff in order to accommodate the far more important heart, so they know their place.
Bladder, don't waste my time, D. Urethra, E. Ovaries, S tier. Testes, E tier. Why so different? Well, maybe just to wind up the red pill boys. But come on, get a good kick in the knackers and try to tell me that the testicles are the pinnacle of design. Intelligent design, box. Penis and vagina, you're fine. You're doing a good job, but you already get way too much attention. I don't want to enlarge your egos any further. Solid B-tier.
Cervix and breasts take a knock due to just being way too fond of cancer, but breasts have maintained an A-tier ranking due to literally being the reason we're called mammals and, of course, providing nourishment to miniature humans.
Skin, truly horrendous, F-tier at best. Skeletal muscle, sure, they look nice. But have you ever cramped up so hard that you limp for a week? I have, but I'm feeling generous so they can be B-tier. But smooth muscle, just goes about its job without any fuss, doesn't need any attention, A-tier.
Mesentery. If I wanted an apron made of fat, I would have gone to an all-you-can-eat barbecue. Eyes, pretty cool. I like the fact that they possess the fastest and strongest for their size muscles, although technically I guess that's muscles.
But RGB vision is a pretty major buff for the human build, which can be traced to a viral infection that we subsumed into our DNA millions of years ago. But 10 million colors that we can see is paltry compared to some birds, for example.
And we've got a blind spot in our retinae due to them being put on backwards, with the blood supply in front of the visual receptors -- a mistake that, say, cephalopods do not make -- and we have to view everything upside down and flip it in our brain, but due to their sheer complexity they've got to be S-tier.
Ears, B. Nose and olfactory center, A. We can apparently discriminate 1 trillion odors, allegedly.
Now, the heart is an organ that I personally have no connection with. I have no conflicts of interest to declare here and I'm entirely unbiased when I say it's god-tier. I know. I was pretty dubious of it scoring so highly on a channel where a suspicious number of videos seem to be about the heart, so I demanded a recount. But blow me down, it was the same result and it came out on top once again.
The heart never takes a break. Most of you will expect it to beat about 3 billion times without any reprieve. Because if it did stop momentarily, not only would the whole body lose its supply of oxygen, but so would the heart itself.
It's the only organ that is responsible for its own blood supply, which it receives at the opposite time to everything else. The heart squeezes blood to the body, but it's when it relaxes that it kind of sucks blood into its own arteries.
The heart pumps about 5 liters a minute at rest, your entire circulating blood volume, but it can boost this up by a factor of 8 or 9 in a fit person. The heart isn't selfish, despite working so hard. It only consumes about 5% of blood flow.
It's the very first organ to form in the fetus. You're born with about 50% of the heart cells you die with and after infancy they simply don't respawn. They are the thoroughbred horses of the body, bred for one purpose, to be the most efficient pumps possible, which also means that they can no longer divide, causing heart cancer to be vanishingly rare.
If you were to remove the heart from the body, it continues to beat on its own. That's what it wants to do. It's the engineer's organ, both an incredible pump and an electrical circuit all in one. This is to mention nothing of the heart's central role in all of human cultures, in literature, art, love, and everything great in the world.
We've been obsessed with the heart since before we were even humans. Because when a blue whale was dissected in Canada, you think they opened a museum exhibit of its brain, of its colon? The only thing people wanted to see was its heart and looking after your heart is the best way to live a long life. Was there ever any doubt? The heart is god-tier.
There you have it, the official and final human organ tier list. Feel free to leave some angry comments below, and I'll be happy to explain why you're wrong.
, is an interventional cardiologist, internal medicine doctor, and university researcher who makes science videos and bad jokes. Offbeat topics you won't find elsewhere, enriched with a government-mandated dose of humor. Trained in Cambridge; now PhD-ing in London.