Lex Fridman PodcastJonathan Reisman: The Human Body - From Sex & Sperm to Hands & Heart | Lex Fridman Podcast #297
EVERY SPOKEN WORD
150 min read · 30,018 words- 0:00 – 1:06
Introduction
- JRJonathan Reisman
We have two tubes that are right next to each other in the throat. One is for food, drink, saliva, mucus, snot, whatever you're gonna swallow. All of that stuff must go down the esophagus, the food tube, and end up in the stomach. And right next to the esophagus, millimeters away, is the windpipe or the trachea, which goes down to the lungs.
- LFLex Fridman
Throat, heart, feces, genitals.
- JRJonathan Reisman
Every organ, from moment to moment, keeps us alive and ensures our survival. The genitals are s- in a way, the opposite.
- LFLex Fridman
How would you improve the penis and the vagina? The following is a conversation with Jonathan Reisman, a physician and writer of The Unseen Body: A Doctor's Journey Through the Hidden Wonders of Human Anatomy. He has practiced medicine in some of the world's most remote places, including the Alaskan and Russian Arctic, Antarctica, and the Himalayan Mountains of Nepal. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description, and now, dear friends, here's Jonathan Reisman.
- 1:06 – 10:21
Hands
- LFLex Fridman
You wrote a book called Unseen Body, all about the human body, the messy, the weird, the beautiful, and the fascinating details. So, from an evolutionary perspective, are most parts of the human body a feature or a bug? Is it, like, the optimal solution or just a duct tape solution?
- JRJonathan Reisman
Great question. I think that most of the time, the way the body works is the best solution. Uh, I haven't seen many alternatives, so it's hard to compare. (laughs) But, um, I think, you know, there are some parts of the body that make more sense than others. You know, the way our hands work, for instance. Um, you know, the muscles are up in the forearm and then the tendons kind of come down like, uh, strings on a puppet. And just the dexterity it gives our hands is just really, uh, amazing, and it's hard to imagine a better- a better tool than the human hand to do everything from, you know, hold things, to, um, play piano, and do a million other daily activities that we do. Um, one thing I talk about in the book, there's some other body parts that seem to be lacking that kind of brilliant, um, design, such as the throat. You know, where the, uh, food, drink are swallowed and air is inhaled, and they kind of... those two paths come within millimeters of each other. And you slip up once, you laugh while eating, or you speak while trying to swallow, and you die from choking. So, it seems less than optimal. Though I'm not sure it could be better from th- the way we're kind of formed in the womb, as a... beginning as this tiny little tube. I don't think it could've been done any better or there's any other way to do it, but it is an unfortunate thing that, you know, does lead to some problems.
- LFLex Fridman
So the hand, if I could just linger on that for a second. You talk about the wisdom of a design in the book. What are the important things about the hand? It seems, like, very useful for many things, and it seems to be quite effective. A lot of people think the thumb is foundational to, um, to th- y- human civilization. Um, is there any truth to that?
- JRJonathan Reisman
I think that is true. Actually, one of the ways in which the importance of individual fingers comes, uh, to attention is when people have severe injuries to their fingers. For instance, um, I have a story in the book about a guy whose thumb is nearly ripped off by his dog's leash. And, you know, when we... when plastic surgeons, who are often the ones to repair that, sometimes it's orthopedic surgeons, they will debate, you know, how important is it to save this finger or how important is it to save, you know, let's say, the kind of tip, uh, the one-third... the tip 1/3 of one of your fingers. You know, it depends on the length that you lose, it depends on which finger. And so the thumb really is the most crucial, um, just, you know, for your occupation, in most cases, to just daily life, um, and your ability to get around, take care of yourself and others. So, you know, the- they'll be more... they're willing to go further, do more surgeries, more aggressive therapy to save a thumb, let's say, um, than, you know, the tip of your pinky finger. So in that way, I do think the thumb, you know, does seem like the most important in many ways.
- LFLex Fridman
It's nice that there's backups. I wonder if that's part of the future. Or is it just the symmetry that nature produces? You think... you think the two hands is- is like... is it about the symmetry or is it about backup?
- JRJonathan Reisman
We'd be much less formidable hunters, gatherers, uh, survivors in any way if we only had one hand, so I think that is important to have two so we can... you know, even everything from kind of, uh, spearing an animal to firing a bow and arrow to butchering an animal, you really need two hands to do it very effectively.
- LFLex Fridman
But can you do a better job with three?
- JRJonathan Reisman
Great question. (laughs)
- LFLex Fridman
(laughs) And we'll never know perhaps. Um, you tweeted... Now, I'm gonna analyze your tweets like it's Shakespeare sometimes. You tweeted that, quote, "Millions of years of sex and death designed the human body." It's like poetry. Are those two basic activities, uh, basically summarize everything that- that resulted in humans on Earth? So, like, uh, is it... is that a good summary of the evolutionary process that led to this conscious, intelligent being, is dea- death and sex?
- JRJonathan Reisman
In a way, yeah. And so sex is how more of us get made, obviously. And death is how we get weeded out or the gene pool gets weeded out and certain genes survive and others don't. And, you know, the age at which we die, whether it's before we've, you know, had sex and reproduced ourselves is a big factor in who survives, who doesn't, who passes on their genes, and what the future of the body looks like. You know, who lived and who died before they were able to be at reproductive age a million years ago was pretty important in what we look like now, um, and perhaps w-... how we have sex and die now will determine what we're shaped like, unless technology has an even bigger role in that, you know, a million years from now.
- LFLex Fridman
So you think that's fundamental to, like, if there's alien civilizations out there that have, uh, the same order of magnitude of intelligence or greater, do you think that we will see something like sex and something like death? So the reproducing and the selection process, plus the, uh, weeding out of the old to make room for the new, is that kind of foundational to life?
- JRJonathan Reisman
I would think so. I mean, it sure seems to be on earth. You know, perhaps in some distant future when m- medicine is nearing, you know, perfection and people can live a really long time, uh, maybe we won't even need to reproduce as much, uh, or- or something like that. You know, it's hard to even know what- what life will be like in the distant future. But I would guess that any alien civilization will have the same dependence on who- who has sex and who dies.
- LFLex Fridman
Well, that's the problem with immortality. How are we going to clear out the old to make room for the new which is kind of, um... It's- it's like a framework of adaptability to changing environments. So as long as the environment is changing, and it seems to always be, um, because it's the entirety of the earth system is a complex system, it seems like you have to adapt. And to adapt, you have to kill off the stubborn, old ideas. And, uh, unless there's a way to, like, not become stubborn and old, but it feels like th- the nature of wisdom is stubborn and old. Like, that's- that's what wisdom is. It's like the lessons of life solidi- the lessons of experience solidified, and the solidification is the thing that actually prevents you from reinventing yourself to adapt to the new, um, change in conditions. But then again, why not have that both those modes? Like, I have two minds in one person. One immortal person that, like, in the morning, they act like a teenager. In the evening, they act like a old wise man. That's possible. So you see, you can imagine (clears throat) within one mind, um (clears throat) , both modes, but those are required. You have to have- you have to have the ability to completely reinvent yourself, which is what death does in an ugly way, or a beautiful way depending on your perspective, depending whether you take the human perspective or the human- uh, the, uh, nature's perspective, and then you have to have the selection. So competition, so sexual selection. It's an interesting- interesting little planet we got. What's the weirdest part, function, concept, idea about the human body to you? We'll- we'll talk about fascinating details. But what's- y- you- I should say for people that should, uh, read your book, they will come face to face with the fact that you do not shy away from the weird and the wonderful of the human body. It's like, um... It's fun, but it's honest. Uh, so given that, (laughs) uh, sorry to make you pick one of your children, but, uh, what's the weirdest one would you say?
- JRJonathan Reisman
The weirdest body part, um-
- LFLex Fridman
Or concept or function. So the chapters, you divide it up kind of into parts, but there could be a thread that connects all of them, the weirdness maybe- or maybe the- the texture of the substance. It could be the liquids, the solids, I don't know.
- JRJonathan Reisman
Definitely every body part and bodily fluid has their own, um, kinda both gross and fascinating aspects. That's probably why I- I'm a generalist as a doctor and couldn't just, as you said, pick one of my children, become a- a specialist 'cause I like them all. Um, I feel like one of the strangest concepts about the human body is that kind of the aspects of it that are the most universal that we all do are the most taboo socially. Um, I wouldn't have expected that if I had, you know, just looked from the outside. Like, what we do in the bathroom, what we do in the bedroom, what we do to our own genitals, what we do to our, uh, you know, quote-unquote "private parts." They're private, even though it's sort of the- the thing that we have- all have in common, um, is the most we try to hide from other people and don't talk about in polite company. I mean, it makes sense as a human living in a society, but from the outside, it sort of might be surprising.
- LFLex Fridman
How do you make sense of that
- 10:21 – 20:01
Sex
- LFLex Fridman
if you put on your Sigmund Freud hat? The thing we all do, why do we make that a taboo thing? Is it because we like taboos? Maybe we get off- or maybe our- our- our kinks as humans is to have taboos, and it's kind of efficient to have taboos about the things that everybody does. Like, you can make walking taboo (laughs) or something. I don't know. But just, uh, maybe that's what we love, that's what's exciting to us is the- is the forbidden.
- JRJonathan Reisman
I think, yes, society loves rules for sure. They... Loves... Some societies more than others. You know, they love, uh, controlling how you think and what you do in public versus in private. You know, and there's a lot of societies where, for instance, parents have sex in front of children. Um, not... You know, for instance, like, in- in- in a traditional Inupiat Eskimo societies, that was sort of normal. I mean, but what are you gonna do? Go outside in the middle of the winter-
- LFLex Fridman
Yeah.
- JRJonathan Reisman
... in the Arctic and do it out there? Of course not. So, um, you know, there's different, uh, (laughs) different taboos in different societies. Some- some taboos make perfect sense. Some taboos are even public health measures, you know, like, uh, as I talk in the book about in- in India where they, uh... You know, the hands are symmetric, as you said, but in Indian culture and- the left hand is taboo. And the right hand is what you use for shaking hands, for eating, for other things, and the left hand is the dirty hand that you use for wiping your own bottom. You know, that's the toilet paper is your left hand. So, um, while the body is anatomically symmetric, the taboo creates this pretty intense asymmetry. Uh, but for a good reason, you know? Yeah, you probably shouldn't be shaking hands with other people with the same hand that you use to kinda clean your bottom. So in that sense, it makes sense.
- LFLex Fridman
... yeah, maybe the roots of it makes sense, but the way it propagates, especially as the times change might not, 'cause you can wash your hands. Um, but the, the taboo remains.
- JRJonathan Reisman
Right, society is very slow to change.
- LFLex Fridman
What is the most fascinating part, function, or concept in the human body? So, you know, something that fills you with awe.
- JRJonathan Reisman
I guess the most obvious one is the brain. Partly because it's so, you know, sort of poorly understood, though we understore- st- understand more than we ever have in the past. There's still so much that we don't understand about how the lump of matter in our skulls kind of creates this subjective experience that we all kind of understand quite viscerally. Um, that's an easy one. I, I would say the kidneys are an underappreciated organ. Uh, they... The, the way they tinker with the bloodstream, raise levels of this, lower levels of that, kind of our entire lives from, uh, inside the womb until we die is just really incredible. And when you look at how much energy different organs consume, the brain and the kidneys are, are two of the biggest ones. Because the brain obviously in us is always active and controlling parts of the body, but the kidneys are just consuming a ton of energy to do what they do. They're kind of the unsung hero of the body, relegated to the back of the abdomen like some forgotten organ. But they're, they are great. I did consider being a nephrologist, which is a kidney specialist, 'cause I was so taken with the kidneys. But, uh, you know, decided I like all the organs so couldn't pick just one.
- LFLex Fridman
So, your book is ordered in a particular way. It's throat, heart, feces, genitals, liver, pineal gland, brain, skin, urine, fat, lungs, eyes, mucus, fingers and toes, and blood. All right. First of all, great, great, uh, chapter titles. Uh, is there a reason for this ordering or is it all madness?
- JRJonathan Reisman
There's a few different reasons that went into it. Um, I did wanna start with the throat for, uh, the reason that it kind of presents, uh, the topic of death, which is sort of obviously very important in the training of a physician, in the career physician. It's a big part of what I deal with. You know, on the first day of medical school, uh, we started the dissection of a cadaver in the class called Anatomy Lab. And so in a way, we were kind of thrown right in there in the beginning. Like, this is the end of the human story, you know, and understand this, and then we sort of backed up to the beginning with embryology and reproduction and stuff. So, it's kinda like we got, and I got thrown into that right in- right away, right in the beginning. Kinda like, "Here's a dead body. Now, start cutting it apart and learn the name and function of absolutely every bit of flesh."
- LFLex Fridman
How did that change you, that first experience with the cold honesty of human biology?
- JRJonathan Reisman
Right, that's exactly what it was. It's cold honesty about the, kind of the story of, of each individual human body. It has an end and that's it. Um, I think that... Well, actually before the end of that first day... So, what we did on that first day was study the superficial muscles of the back, like the lats or latissimus dorsi, and some other muscles. You know, we cut through the skin of the back. My cadaver was laying face down on this metal gurney. We pulled back the kind of plastic sheets that would keep him moist for the next four months as we dissected him. Cut through the skin on his back and then started dissecting through the superficial muscles of the back. And that was really all we saw that first day. Uh, we didn't get any deeper, didn't enter the abdominal or, or chest cavity to see internal organs. But I was so fascinated with this sort of behind the scenes look at how things work in the body, how you move your arms, how you arch your back, you know, these are the muscles that do it, that I decided I wanted to donate my own body for the same purpose. Um, so I made that decision literally before the end of that first day of class, and I- I'm still sticking to it. Uh...
- LFLex Fridman
So, someday there will be a medical student that can watch and listen to this podcast and while dissecting your body.
- JRJonathan Reisman
It could happen. They might not know that that person they're listening-
- LFLex Fridman
Oh, sure.
- JRJonathan Reisman
... to on the podcast will be the carcass in front of them-
- LFLex Fridman
Yeah.
- JRJonathan Reisman
... but, uh, like, we don't... We never learned it.
- LFLex Fridman
The universe will know.
- JRJonathan Reisman
The universe will know.
- LFLex Fridman
A- a- and, and they will acknowledge the irony or the humor, the absurdity of that.
- JRJonathan Reisman
The universe will chuckle, but the medical student won't know because they never, as I did not, learn any, uh, you know, personal information about the person. Only what I could glean from looking inside him, which actually tells you quite a bit. I knew he was a smoker. I knew he had coronary artery disease. You know, you, you get a, a window into... I knew he was overweight. You get a window into people's lives just by looking in their, in their bodies after death. Other, other, um, cadavers in the lab, not my own, or th- I shared one with three other students, but other cadavers, some had, you know, metal joints, like a knee replacement. Some had a kidney missing, so they probably... And we could tell it was surgically removed, not that he was born with one. Uh, and we could tell that he probably had a kidney tumor or cancer that was removed. So, you, you do get an insight into people's lives from, you know, picking them apart after they're dead, uh, but you don't know their name or, or what podcast they've been on.
- LFLex Fridman
(laughs) So the... As the book title says, Unseen Body, so it, it tells some kind of story of your life. So, it does capture the decisions you've made in your life, the things you've done that might be kind of secret, uh, to, to that person and maybe to a few others that knew him or her well. That's so fascinating. So, what kind of things can it reveal? Like, what kind of choices in terms of the injuries, the, the, the catastrophic events, the lifestyle choices of smoking and diet, and all those kinds of things? What, what, what, what can you see? What kind of history can you see about the human before you?
- JRJonathan Reisman
So, all those things you mentioned are things you can see. You can... You know, take the skin, for example, right? Most things that happen to us leave a mark, uh, you know, s- as I say, a kinda a story written in the language of scar, where it tells you injuries you've had. And the same thing with animals, you know, I...... I have seen deer hides that have marks that look like they were made by maybe a barbwire fence, something like that. You can tell, you know, y- you, sometimes it's conjecture, but you can sort of imagine what might have happened to cause that. Perhaps a, you know, two bucks were fighting and one got injured with an antler. Um, and the same with humans. You know, I have scars on my body, and when I notice t- them, I remember what happened. You know, I got a big cut on my hand when I was 13, and it's still there. And I remember what happened, uh, you know, every time I look at it. And so in that way, uh, e- only I might know that story. But other people, you know, when they dissect me and notice the same scars, they can kind of, uh, it can fire their imagination, as my cadaver, you know, did for me.
- LFLex Fridman
They know that there is a story there. That's such an interesting way that the skin does tell a story. Uh, b- both tattoos and scars. (laughs)
- JRJonathan Reisman
Right. And even-
- LFLex Fridman
Some of the fun you've had and some of the damage you've done.
- JRJonathan Reisman
Right. And even when I, when I evaluate a patient, I u- can use scars to help me make medical decisions. So for instance, someone that comes in with abdominal pain into the emergency room, you can see scars on their abdomen that tell you about, you know, the past kind of activities of a surgeon, perhaps. I know, I recognize the scars that are left when someone has their gallbladder removed, the scars when someone has their appendix removed, when, maybe when someone's had a hysterectomy, and that can tell you what it might be or what it isn't. You know, if someone doesn't have an appendix, their abdominal pain's not appendicitis, end of story. So in that way, I'm sort of looking at these, the, the tracks or the footprints of past surgeries to tell me what, what might and might not be the cause of this patient's abdominal pain, which is kinda my main job in the ER, is figuring out what's causing it and to help them.
- 20:01 – 29:08
Future of medicine
- LFLex Fridman
Is there ways to get more data about the human body as we look into the future o- of, uh, medicine and biology that would be helpful to fill in some of the gaps of this story? So, you know, you have, you have companies, you have research that looks at, you know, uh, collection of blood over long periods of time to see sort of the, you know, paint a picture of what's happening in your body, mostly to help with lifestyle decisions, but, but also just, you know, to anticipate things that can go wrong and all that kinda stuff. Is there, can you just speak to, um, a greater digital world that we're stepping in, how that can help f- tell a richer story?
- JRJonathan Reisman
I certainly think that we have more data than we know what to do with right now, especially with kinda direct to consumer medical devices, you know, smartwatches, et cetera, that are just collecting these reams of data. I have not seen them put to, I think, the eventual use that they will. Um, I think that the potential is, is sort of just, um, you know, unimaginable. And I hope we're heading into a new age where, you know, you can determine, for instance, is a, is a person gonna have more of the dangerous side effects to a drug based on their genetics, or are they gonna tolerate, uh, one drug better than the other, you know, based on, on their genetics? And we are slowly moving into that age, and especially the age of kind of completely synthesizing drugs in a lab, um, you know, much like, um, for instance, some of the COVID vaccines, actually. Like Moderna never had a vir- the virus in their lab. They made that vaccine completely without ever having the virus themselves, just by having the genome, which is sort of astounding, and there's a lot of potential going forward, you know, based on that technology and some others.
- LFLex Fridman
Oh, I didn't know that. So they, basically, it's all in the computer. It's computational.
- JRJonathan Reisman
Right, you have the genetic code, you have tremendous power, even if you don't have the organism itself.
- LFLex Fridman
What do you make of Elizabeth Holmes and efforts like that? First of all, I am, uh, a, um, curious... I'm drawn to the darkness in human nature because that somehow reveals, um, the full spectrum of what humans could be. So there's a lot of sort of controversial thoughts about who she is and her efforts and so on. Um, I think you maybe even tweeted about it, but I've read a lot of your tweets, so I'm now forgetting. Um, but what do you make of her and those eff- both those efforts and the charlatans, uh, that sort of, um, snake oil salesmen that promise those efforts to do more than they currently can?
- JRJonathan Reisman
I think that her, you know, that goal that she had, that she created Theranos to try to achieve, to use less blood in tests is a very worthy goal and a huge frontier that we have not achieved and that I hope we will achieve. So I understand why, you know, w- someone describes what a huge step forward that would be, and it would be indeed. I understand why people put a ton of money behind it.
- LFLex Fridman
Can you describe what was the promise? What, what are we even talking about? What's Theranos? What... Just, uh, for people who don't know.
- JRJonathan Reisman
So Theranos is a company that was basically started to revolutionize the way medical blood tests are done, both to use a whole lot less blood in doing it. You know, if anyone's ever been to the doctor and had five to ten tubes of blood removed from them, it can be, uh, quite surprising how much they take out. Uh, and, and it's... You know, th- that's the limitation of our technology, that we need those volumes of blood to run all the tests that we want to. And so th- the promise of Theranos was that perhaps with a single drop of blood, we would be able to know as much about the person's... The condition of their, their body, um, without drawing all that blood. And, and thereby, you know, there would be these devices she was gonna create that would sort of do it, you put a drop of blood in and it spits out everything you ever wanted to know about what's in your bloodstream, and in a way, that would make it so much easier. You know, it could be, you could have one in your home theoretically, and you... I don't know why you'd wonder what your potassium level is on any given day, but you could check if you wanted to. Um, and so that, that goal is very worthy. You know, I, I put that goal up there with, uh, the, the frontier of making painkillers that are as good as opioids without the addictive quality. You know, that would be such a huge revolution if we did have that in medicine. But-And particularly for me, 'cause I trained in both pediatrics and internal medicine, so I learned to care for both children and adults. In children, we do draw much less blood. They have a much lower blood volume, and we use these tiny little tubes to draw their blood, and we seemingly get equivalent information out of the larger tubes we draw from adults. And I'm still unclear, to be honest, why we can't draw that little amount of blood from adults. It seems technically possible. I don't know what the barriers are. I'm sure there are, or else we'd be doing it. Um, but I do think that it is a, a very important goal, and if Theranos had done it, they would have really revolutionized the practice of medicine.
- LFLex Fridman
So to, uh, return to that, uh, cadaver that first day, uh, when you got to meet with the, with the dead, with the human body that's no longer living, so how, how quickly did it take for you to get used to sort of, uh, you said looking at the surface muscles of the back. I mean, that can be overwhelming as a thought, and people listening to this that have never dissected anything might, might be overwhelmed by that thought. So, like, how quickly were you able to get used to th- the brutal honesty of the biology before you?
- JRJonathan Reisman
For me, it did not take long at all. I, I guess I've ne- not, never been a squeamish person, so for me, it was kind of riveting and fascinating right from the first moment. But I do know some of my fellow classmates did have some trouble with it. Some of them I heard had nightmares in the first few weeks of, of anatomy lab. And, but then everyone, as far as I know, got used to it. And that was also actually a big lesson for me, that it's pretty amazing what people can get used to in their daily lives, and I kind of extrapolated that to people living through war and through, you know, just terrible s- uh, situations, and living under, um, you know, oppressive regimes, and it, it really is amazing what people can get used to. Almost anything.
- LFLex Fridman
But, you know, in war, people often come back and they have nightmares. They suffer through it. There's PTSD. There's, uh, there's a lot of complicated feelings with that. Are echoes of those same complicated feelings possible in the case of training to be and becoming a doctor?
- JRJonathan Reisman
That's a good point. Yeah, I think, you know, sometimes, uh, just as, you know, a barbwire fence can leave a scar on your skin, you know, emotional, uh, psychological experiences can leave a mark on your brain or your memory. And I think that, uh, that definitely could be, um, could be a problem i- in medical training. You do see a lot of things that are very shocking, very repulsive, um, things that you never forget. I know one of those, uh, students that had nightmares initially went on to be a surgeon, so I imagine she's not having the PTSD of kind of seeing inside her first dead body, 'cause she sees inside them all day every day now. But I'm sure it, it could. You know, we, we go on to see so many, um, kind of grosser or more shocking, uh, things in medical training through medical school and then by working with actual living patients, not just dead and embalmed bodies. So I do think that things can leave a mark, but I don't think that initial cadaver would be the most traumatic.
- LFLex Fridman
(sighs) Yeah, but maybe some of that trauma, the demons make you a better surgeon. Just like, um, some of your own psychological trauma might, might make you a better psychiatrist. Returning to the ordering, is it order or is it chaos through the ordering of the chapters, from throat, throat and heart and feces and genitals all the way to fingers and toes and blood?
- JRJonathan Reisman
So I, I did mention that, you know, throat was the first one 'cause I kinda wanted to throw the reader right into the, the brutal honesty of death, and I followed it up with feces as the third chapter in, in a way partly to also throw them right into (laughs) the deep end of how I like discussing parts of the body and revealing their gross and fascinating aspects. So I didn't want to hide anything. You know, when you train to be a doctor, everything is on the table, literally, in the cadaver lab, but also just, you know, you deal with blood and piss and vomit and feces, and that's kinda the medium of your craft and...
- LFLex Fridman
(laughs)
- JRJonathan Reisman
And, uh-
- LFLex Fridman
Yes, the medium of the craft, that's right.
- JRJonathan Reisman
Right.
- LFLex Fridman
(laughs) Like, if you're a painter, this, (laughs) this is the paint that you're w- (laughs) that-
- JRJonathan Reisman
Exactly.
- LFLex Fridman
And then you have to create a masterpiece with it. Uh, like almost like a dance, 'cause there's multiple painters. One of the painters is the biology.
- 29:08 – 39:32
Throat
- LFLex Fridman
So let's return to throat. You mentioned it's a weird one. So first of all, a friend of mine said, "I, I just see humans as a, like, a bunch of holes. They just walk a- walk around." (laughs) So...
- JRJonathan Reisman
Not untrue. (laughs)
- LFLex Fridman
(laughs) It's a funny way to look at humans. So we have ears, we have nose, uh, we have mouth, we have, um, the sexual holes, vagina, penis, and then, uh, you know, what's the, uh, uh, medical term for your asshole? (laughs)
- JRJonathan Reisman
Anus.
- LFLex Fridman
Anus, thank you. Uh, this, (laughs) this is a very technical discussion.
- JRJonathan Reisman
The rectum's further in. Don't confuse-
- LFLex Fridman
For-
- JRJonathan Reisman
... the two.
- LFLex Fridman
Oh, that's very impor- what, what, is there a difference between throat and mouth, by the way? So when you say throat, are we talking about when that hole actually became, becomes tubular?
- JRJonathan Reisman
Th- the throat I would count as just sort of the very back of the, of the, you know, the back of the mouth, where the nose also comes down and meets it, uh, where the tonsils are and the uvula. Um, but you're right, that, you know, we are a bunch of holes, but more accurately, we're a tube, right? We start in the womb as kind of this microscopic little disc, almost like a, a, uh, you know, a flatbread, and then we're, we roll e- almost like a burrito into this tube. And we're a simple, microscopic tube, and from there, we grow into this bigger and bigger tube and we become more complicated. And each end of the tube does split into various holes. So all the holes you mentioned at the front end of the tube, the front end of our body, right? It splits into the nose, the mouth, uh, the ears, the sinuses, the, the...... Tube to the, uh, lungs, which is the windpipe, the tube down to the stomach, which is the esophagus, and then the other end of the tube splits as well. Uh, h- you know, men end up with two holes and women end up with three holes. Um, you know, the urethra, the vagina, and the anus. In men just, you know, the urethra and kind of the reproductive system, they share a hole. So, um-
- LFLex Fridman
I'm learning a lot today. It, it really is incredible that you start from sperm and an egg and you have some DNA information, and from that the building project begins. And then what that leads to is like a, like a, like pizza dough and then you roll it into a tube, and that tube then, um, eventually sort of becomes more and more complicated and gets eyes and a brain, and then, uh, can create, uh, a Twitter account. So for, so from ... It's- it's really incredible that we're just a fancy tube.
- JRJonathan Reisman
Right. We are. And we sprout eyes, and a brain, and a sense of smell and taste pretty much to regulate what comes in the front of the tube, you know. We don't want to eat anything dangerous or poisonous, you know. We want to choose what we eat, even choose who we kiss.
- LFLex Fridman
Well, we seem to be motivated by what comes out of the tube as well, in part. Right, that's not just output, it's a feedback mechanism seemingly. Like we're also monitoring, uh, the functioning of the output. We're not just obsessed about the input. (laughs)
- JRJonathan Reisman
We're very obsessed with the output.
- LFLex Fridman
(laughs)
- JRJonathan Reisman
You're absolutely right about that. Uh, people-
- LFLex Fridman
Yeah.
- JRJonathan Reisman
... you know, have medical complaints a- about their output very often that are ... You know, I'm never, I never cease to be surprised by a new kind of complaint or observation about the output.
- LFLex Fridman
I think people have gone to wars over-
- JRJonathan Reisman
(laughs)
- LFLex Fridman
... the output and, uh, maybe sometimes the lack of the output, or the desire for output with a particular other humans, um, that you, you fancy the brain and the eyes that sprouted, somehow convinced the, the rest of the body that this one particular other tube is fanciful, so you're going to go to major wars and lead global suffering because of, because of the fancy and the desire for additional output with the other, uh, tube. Okay. So that's ... So, uh, on the throat, that part of the tube, is it ... Uh, you said the design is not ... You could have thought of maybe a little bit better options because it's too multifunctional. Is that ... Can you sort of elaborate on the multifunctional nature of this part? Are a lot of parts of the human body multifunctional or do you find that more specialization is going to get the job done better?
- JRJonathan Reisman
There is a lot of organs, for instance, do have multiple functions, you know. The pancreas is, has two, is like two organs in one. One, you know, secretes hormones like insulin into the bloodstream and the other aspect of it secretes, uh, digestive enzymes into the gut to help you, uh, digest and absorb food. The liver is like 15 organs in one. It's just amazing how many different things it does. But the throat, you know ... So basically the problem with the throat is, as I said, we have two tubes that are right next to each other in the throat. One is for food, drink, saliva, mucus, snot, whatever you're gonna swallow. All of that stuff must go down the esophagus, the food tube, and end up in the stomach. And right next to the esophagus, millimeters away, is the windpipe or the trachea, which goes down to the lungs. And your, your throat does these daily gymnastics to keep everything but air out of the windpipe because, you know, you slip up once and you can die. Uh, you can choke. You know, you laugh or speak while eating and, and it's curtains unfortunately. So, it seems like, you know, every aspect of the body, when I was learning about it in med school, seemed so brilliant and so perfectly designed by evolution or whoever you might think designed it, um, to, you know, favor survival, to e- enhance life, uh, but the throat seemed the opposite. It seemed set up almost for failure. And, uh, you know, we developed all these mechanisms as a compensation, right? We have the gag reflex whenever s- food or something is headed towards your air pipe, your windpipe or down to your lungs, your throat has this sort of, like, rejection of it, it pushes it away in a gag reflex. At the same time, we have a cough, which is something w- our body does when something inappropriate does get down the windpipe. You know, when we get a little food down the wrong pipe, uh, we end up coughing, and the coughing does usually flush it out, um, and get rid of it. We even have something called the mucus elevator in our lungs, which is this constant flow of mucus up the airways, up to the trachea, dragging with it all kinds of particulates that we've inhaled and perhaps some food that went down the wrong pipe, and drags it up into the throat and we swallow it kind of unconsciously all day every day is the truth. Even the mechanism of swallowing is super complicated. You know, it uses a number of cranial nerves. It's, uses over 15 different muscles. Um, it's this coordinated act to keep food out of the airway. You know, it l- you can see someone's Adam's apple in their neck kinda jump upward when they swallow, which helps lift the airway up against this ki- the, the epiglottis, which plugs it closed and allows food or swallowed drink to kind of skirt just past it. But every time we swallow, those things do come within millimeters of going down the wrong pipe, and it's just thanks to these kind of compensations, these adaptations we have to the danger of the throat that, that keeps us alive.
- LFLex Fridman
As I actually took a sip of, uh, water, it's, it's kinda ... It makes you appreciate the wonderful machinery of it all. Uh, by the way, we have, uh, pulled up your Instagram that people should follow. You have a post about the throat and, and just showing so many different ...... components from the tongue to the trachea, the esophagus, just the entire machinery of it all. (sigh) The teeth for the chewing. It's so interesting, and so a lot of the structure of this, the anatomy and the physiology, does it echo other mammals? Are, are we... So is, are we just basically borrowing a lot of stuff from evolution and maybe making small adjustments, maybe due to the fact that we're not using our mouth to murder things as other predators might?
- JRJonathan Reisman
Right.
- LFLex Fridman
Uh, we use their thumbs.
- JRJonathan Reisman
Exactly. We have hands, we don't need to bite them. Um, yeah, there's a lot of overlap between, um, different animals, which I find, uh, very comforting and fascinating. You know, someone asked me, "Is there any animal in which the throat is better designed?" And I, my first thought was whales 'cause the blowhole's kind of up on the top of their heads.
- LFLex Fridman
Mm-hmm.
- JRJonathan Reisman
So I was thinking, "Oh, maybe, maybe they are se- more separate." But when I looked into it, actually no, you know, the paths do come very close just like in us. And, uh, I saw a paper about some new discovered organ that actually helps keep food and drink out of the airway in whales that they had never noticed before. So it's a different mechanism, but the same kind of basic problem is that, you know, we're tubes and the air tube and food tube are right next to each other.
- LFLex Fridman
How well do we understand? So just even lingering around this little part, is there still some mysteries about the complexity of the system? 'Cause you mentioned just even for swallowing all these parts in the brain that are responsible and all, all the different things that have to like an orchestra play together. Do we have a good sense from both a medical perspective and a biology perspective, or is there still mysteries?
- JRJonathan Reisman
There's definitely still mysteries. We understand a lot about, for instance, how the swallowing mechanism, you know, is coordinated. It's in the brain stem sometimes using some higher levels of the brain. Um, but it is a very thoughtless thing as you mentioned when you drank the water. You know, it's not something we have to think about, thankfully, or we'd be thinking about it all day. Um, there's a lot we don't understand about the basic mechanisms, perhaps about how the nerves fire and how they kind of, you know, coordinate on the, on the microscopic level. How ions rush into and out of nerve cells to kind of create that electrical signal but we sure understand a heck of a lot and it's very fascinating.
- 39:32 – 47:34
Heart and blood
- LFLex Fridman
Uh, so you, you, you give props, uh, like you said, to the kidney, to the liver, to the maybe to the organs, to the parts that don't often, uh, get as much credit as they deserve. But let us go for a time to the human heart. Um, we get chest pain, uh, we talk about it when we talk about love for some reason. Why do we talk about the heart when we talk about love?
- JRJonathan Reisman
There sometimes can actually be some chest pain involved in love. I remember when I was a med student, I was very smitten with another medical student-
- LFLex Fridman
Mm-hmm.
- JRJonathan Reisman
... who was totally brilliant and beautiful. And it actually does cause this kind of burning in your chest. I don't know what that is. It... I don't think it's from the heart itself.
- LFLex Fridman
Mm-hmm.
- JRJonathan Reisman
I don't know if it was like acid reflux 'cause I was so nervous. I'm not really sure, but I definitely felt something in my chest whenever I saw her.
- LFLex Fridman
Yeah.
- JRJonathan Reisman
I don't know what that is, but you could see why someone might think, "Oh, you know, maybe it is your heart." That's kind of the most prominent organ in your chest. You know, w- when people come to the ER with chest pain, you know, the big question is, "Is it my heart?" And that's my main job is figuring out if it is or not. So I could see why, um, you know, the way ancients saw the functions of different organs is, is fascinating, but often hard to explain.
- LFLex Fridman
Would it be fair to say that if you look at the entirety of human history, the way most people die has to do with the heart?
- JRJonathan Reisman
Well, like in America today, um, cardiovascular disease and, and car- you know, coronary artery disease is one of the most common, perhaps the most common cause of death. You know, 100 years ago, 200 years ago, it was probably not. People were not living as long and people were dying of infections that we tend to die less of these days.
- LFLex Fridman
Sure.
- JRJonathan Reisman
Um...
- LFLex Fridman
That's true. But in terms of things to stab (laughs) -
- JRJonathan Reisman
(laughs) .
- LFLex Fridman
So I'm trying to sort of introspect like why, why talk about the heart and love? My thought would be that is because the heart was seen as the most important organism. It would be like the origin of life comes from the heart, the originator of life. And the way you figure that out from sort of an ancient perspective is, uh, when you stab things, (laughs) what is likely to lead to issues. It's, it's like, it's possible to imagine that the brain is not as special as we might think from when you don't understand modern biology or, um, physiology or neuroscience, all those kinds of things. Especially 'cause pain, you know, it's painless too, uh, if you stab it (laughs) -
- JRJonathan Reisman
Right.
- LFLex Fridman
... the brain, I mean.
- JRJonathan Reisman
Yeah.
- LFLex Fridman
Um, yeah. Anyway, so that's, that's really interesting. I'm sure there's a, there's a kind of a poetic answer too, maybe the way people wrote about it, but what do you as, um, the wisdom in the design of the heart?
- JRJonathan Reisman
I mean, the main function of the heart basically is to push blood through the cardiovascular system, through the branching blood vessels to feed every cell in the body. You know, when I, our, I believe our ancestors started off as single-celled organisms floating in some ancient brew-... and they were surrounded by the medium that would bring them all the nutrients they needed. So, there's no issues there. And then, once you start getting multicellular organisms, the kind of, that are thicker, and the ones on the inside aren't in contact with that sort of nutritious brew that they're growing in, um, you kind of need a way to distribute those nutrients to every cell. And so that's what the heart and the branching vascular tree do. So, the heart, you know, it's, I, the most, the biggest disconnect between how the organ's talked about in poetry and through history versus its actual function is probably the heart, 'cause we ascribe all these things like love and passion, uh, and life itself, sometimes, to the heart. But actually, it's just a simple mechanical pump. You know? That's all it is. I don't want to downplay it. It's amazing. But, um, you know, it just pushes. It s- fills with blood and then squeezes it, fills with blood and squeezes it, and just that squeezing, that pushing creates the pre- blood pressure that you need to get blood to every cell in your body, especially when you're standing upright. To get blood to your brain, you need a certain amount of pressure to get it up there.
- LFLex Fridman
Isn't it amazing to you how much volume of blood just gets pushed through by this, by this pump?
- JRJonathan Reisman
Absolutely. They say every red blood cell takes about five minutes to circulate and come back to the heart. Um, and that circulation kind of, you know, starts at, in the womb and continues and kind of until the moment that we die. Um, but the volume is tremendous, and it can never s- you know, take a break, basically.
- LFLex Fridman
And it's sort of, uh, propagating all kinds of stuff throughout the body. It's a delivery mechanism, blood, for all kinds of good stuff and bad stuff. Nutrition, drugs, all that.
- JRJonathan Reisman
Right. Medications too.
- LFLex Fridman
Medications. Such a fascinating design, isn't it?
- JRJonathan Reisman
And it also takes the waste away. You know, it, uh, kind of brings the nutritious stuff, brings the nutrients, especially oxygen, but many other things, and then it also, as it passes, the cell takes the cell's waste. So, it's sort of the, the freshwater and the sewage system in one.
- LFLex Fridman
So, about blood. What, what to you is fascinating about blood? So, we talk about the pump that spreads the blood, but the blood itself?
- JRJonathan Reisman
Right. So, the blood itself is sort of the, I mean, it's the most important bodily fluid, of course. It, you know, from moment to moment, every cell in the body needs a flow of blood, um, to bring it, most importantly oxygen, but also, again, all the other nutrients, and to take away waste. And if that stops for even a few moments, you can be in big trouble. Um, so blood is sort of, you know, the, the most important medium. It's also, doctors use it to kind of evaluate the body. It does have this kind of all-seeing quality to it, where, um, you know, we can evaluate organs through the blood. I can tell you about your liver, your heart, your kidney, just by taking a sample of your blood. So, it's sort of like this crystal ball, in a way, and we use it kind of all the time, you know, to assess someone's health, to assess their disease.
- LFLex Fridman
Is it also the attack vector for, uh, diseases, for bacteria, for viruses, and all that kind of stuff? So, viruses seem to attack you at the throat. Maybe you can correct me, but they seem to attack different parts of the body depending on how easy it is to access and how easy to, it is to, uh, get in deep, depending on what you prefer. If you want to do a little bit of hard work, but you get in deep, or you don't want to do the hard work, um, but you don't get in deep. Those are the choices viruses have. But is blood one of the sort of attack vectors? What's like, if you were trying to break into the human body, uh, like a parasite, a virus, a bacteria, uh, how would you do it? Like, what would you, what would be the attack vectors you would explore?
- JRJonathan Reisman
Right. So, you gotta look for the body's weaknesses, of course. Um, you know, we have inherent weaknesses, for instance, like our respiratory tract. We have to breathe. We have to get air in from the outside.
- 47:34 – 1:00:02
Genitals
- LFLex Fridman
let us go for a time to the genitals chapter. So, uh, what are genitals? I think I've heard of those. I think I've read about a penis and a vagina. Can you explain to me how those work? Just asking for a friend. But also, um, what to you is fascinating about it, and maybe what's misunderstood or little-known about them?
- JRJonathan Reisman
Sure. So, I'm, they're very unique organs, I would say. One of the things that I like to point out is that, you know, while every organ, from moment to moment, keeps us alive and ensures our survival, the genitals are, in a way, the opposite, you know?
- LFLex Fridman
(laughs)
- JRJonathan Reisman
We, we don't need them from moment to moment. You don't even have to use them at all. Um, and in fact, they often make us do stupid things that are the opposite of kind of enhancing survival. So, and they, you know, they've affected the brain, and you can become sort of focused and nuts based on those desires that kind of stem from the genitals. So, they can be dangerous organs too. Um, but you know, I mean, sexual dimorphism helps with genetic variability, um, as it does in so many other organisms. You know, you take two people and mix 'em together, their genetics, you just get a lot more variation and more opportunities to try different genetic codes and see what'll enhance survival, as we talked about sex and death. I talk about, in the book, a lot of, for instance, the female genital tract, how the uterus is very unusual because, you know, it doesn't even sort of wake up and start doing its thing until the second decade of life. You know, it's, um, even though, you know,... uh, babies, uh, ba-- female babies are born with all of the eggs they'll ever have in their ovaries already. They're just sort of in this stasis until they start waking up, uh, kind of once a month, and it's this, this cycle, you know. There's so much in our bodies that are cyclical and rhythmic, the heartbeat, the breathing. Um, but menstruation is kind of the, a very strange rhythm that takes, uh, over a decade to start and, uh, only, you know, the rhythm beats once a month, which is very slow compared to every other rhythm of the body. The other unusual thing is, you know, in, in medicine, when rhythms of the body cease, when they stop, those are emergencies, right? When your heart stops, that's a cardiac arrest. You need CPR, maybe an electric shock to restart it. When your breathing stops, you know, you need a breathing machine to breathe for you or something to reverse whatever might be causing the suppression of your breathing. But when menstruation stops, it's the point of menstruation in the first place.
- LFLex Fridman
Mm-hmm.
- JRJonathan Reisman
The whole reason that the uterus grows a lining and sheds it each month is to one day, you know, get fertil- get the ovum to get fertilized and for it to implant in the lining, and then the rhythm ceases, and that's obviously not a medical emergency, unlike most other rhythms', you know, cessations, it's the point of the whole thing in the first place.
- LFLex Fridman
So, these particular, penis and vagina are that whole thing, the uterus... Whatever. Am I not using the wrong terms? I don't know.
- JRJonathan Reisman
No, those are-
- LFLex Fridman
I'll just keep saying, uh-
- JRJonathan Reisman
We use those terms. There's more technical... There's parts, various, various parts.
- LFLex Fridman
Yeah.
- JRJonathan Reisman
In medical school, you learn every bump and, you know, every little part of every little organ and including-
- LFLex Fridman
Right.
- JRJonathan Reisman
... the genitals, so...
- LFLex Fridman
I never really, uh, thought of it this way, as you said, is that most organs are kind of full-time employees (laughs) . Like, uh, 24/7, they're doing something. And then there's some organs, uh, penis, vagina being, uh, representative of this, they're not functioning all the time. They're only functioning every once in a while and they get us to do stupid stuff or awesome stuff and all that kind of stuff, but they're not essential for human survival on a second by second basis. And the, the whole cyclical nature of the human body... How many other cycles are on a monthly basis, like, that far apart? That's a, that's a fascinating design that the human body would do that and wouldn't start until the second decade, decade of life. It's almost like, um... What do I want to say? There's some kind of meta-planning going on. Like, this is the optimal solution for the sexual selection mechanism among, uh, like, somewhat intelligent species. Like, it's useful to, after the brain is developed sufficiently long, to now be making sexual selection decisions. Like, you need time for this computer, this really powerful computer, to load in the info. Interesting.
- JRJonathan Reisman
You also need the body to develop, you know. A child simply isn't big enough to be pregnant-
- LFLex Fridman
What I-
- JRJonathan Reisman
... and deliver, uh, you know, another baby.
- LFLex Fridman
I wonder if there's animals in which this happens at a much more accelerated pace in different stages.
- JRJonathan Reisman
Definitely, especially, you know, certain kinds of insects, you know, like d- um, Drosophila, a lot of, um, the fruit fly, a lot of experiments are done on 'cause their life cycle is so rapid, you know. A lot of kind of insects and other creatures are almost ready to mate as soon as they're born.
- LFLex Fridman
(laughs) .
- JRJonathan Reisman
Not us.
- LFLex Fridman
Not us. Is there any improvements to the design? So, a lot of people are very interested in these particular body parts. Um, if you were to sort of step back as a, as a geneticist, biological designer, maybe a computer scientist, computer engineer trying to build, um, human 2.0 or maybe a robot, how would you improve the penis and the vagina?
- JRJonathan Reisman
Well, the penis for starters... I mean, let's also discuss the testicles, you know, they're very important, too.
- LFLex Fridman
Which-
- JRJonathan Reisman
I mean-
- LFLex Fridman
Okay, so they're both... Yes, right.
- JRJonathan Reisman
So, they're fragile and they're important and yet they're hanging off the body in danger, basically. So, um, does that make sense? You know, they begin in the womb, they begin inside the abdomen and they slowly descend and, uh, and sometimes before birth, sometimes in the first year of life, sometimes never, they pop out of the body and end up hanging in the scrotum. There's a reason because the chemical reactions that create sperm function best at a few degrees cooler than body temperature, and so that's why you might notice in the warm weather, they might hang further down, and in the cold weather, they scrunch themselves up to get closer to the body to maintain that ideal temperature a few degrees, uh, cooler. Um, so it's hard... You know, if you could create a sperm production mechanism that did not rely on that lower temperature, that would be great, keep 'em inside the body protected like the ovaries are. Um-
- LFLex Fridman
But, oh, then you wouldn't rely on the lower temperature. I thought you meant create some kind of weird internal cooling mechanism.
- JRJonathan Reisman
No, well, that... I guess that would be one solution, but just maybe a different type of chemical reaction or, you know, would not be reliant on the lower temperature, let's say. Um, you know, it would be great to design a spermatogenesis or sperm production process that would function best at body temperature and then we can keep those delicate organs inside the body and not have them, them hanging out in danger.
- 1:00:02 – 1:04:18
Poop
- LFLex Fridman
What about the neighbors? Poop, feces. There seems to, uh, be a lot of interesting stories in that particular output as well. Um, what- what to you is (laughs) fascinating? What, um... What to you maybe is misunderstood or little-known about poop?
- JRJonathan Reisman
Well, it's hilarious for one thing-
- LFLex Fridman
Yeah.
- JRJonathan Reisman
... that we do it.
- LFLex Fridman
I was about to say. Oh, okay.
- JRJonathan Reisman
The word is great as well.
- LFLex Fridman
Yes.
- JRJonathan Reisman
There's so many different words. I do u- you know, when I'm talking to the parents of pediatric patients, I use the word poop. I don't often when I'm talking to adult patients. Try to choose a- a more mature word. But, um, poop is amazing. I mean, I guess-
- LFLex Fridman
(laughs)
- JRJonathan Reisman
... it's, uh, you know, it's sort of the most- the dirtiest, the most vile, the most hated aspect of our bodies. It's the grossest. We don't wanna think about it, talk about it, have an- it anywhere near our, you know, food or in social interactions. Uh, with good reason. You know, I mentioned gastrointestinal infections are one of the most common infections the human body suffers from. And, you know, what we call... Uh, the way they spread from person to person, grossly enough, is referred to as the fecal-oral route, which is- means s- a bit of someone's stool is getting into your- you're swallowing it, um, you know, through the water supply.... for instance, diarrhea is actually quite a brilliant mechanism, um, of the- these microbes, right? If you, let's say you're in the intestine of one person, your goal is to get into the intestines of a- another person. Brilliant to just trick their intestines into secreting all this fluid into, into the intestines to increase the volume of stool and its runniness so that when they do poop, it gets into the water supply and then everyone else kind of ends up getting infected as well.
- LFLex Fridman
Wow, that's brilliant.
- JRJonathan Reisman
It's genius. Just the same way like, you know, tuberculosis or coronavirus kind of infects your lungs and makes you cough and you send it out into the air and it ends up in other people's lungs.
- LFLex Fridman
And that's all evolution?
- JRJonathan Reisman
Yeah, it's brilliant. So diarrhea is intelligent, um, is a big takeaway lesson.
- LFLex Fridman
It's- (laughs) it's one of the most intelligent things we can do, uh, as a- an entirety of an organism, not just a particular cognitive organism, but there's, there's, you know, we're- we're made up of bacteria and viruses, and there's a lot of visitors and so on. As the entirety of the system, diarrhea is one of our better accomplishments, it's fascinating.
- JRJonathan Reisman
(laughs)
- LFLex Fridman
Um, well, I wonder, why is poop funny?
- JRJonathan Reisman
I think a lot of that is socially constructed, just how it's sort of supposed to be hidden away, yet something we always do, something, you know, we chuckle about as children. And, but even in healthcare, you know, it becomes this big topic of conversation 'cause you end up talking about it constantly. Like in the ER, people come in, I- they're complete strangers, sometimes like a nice old lady who resembles my grandmother, and all of a sudden I have to ask her all about what's happening in the bathroom, like if she's straining, what color is it? What, what, you know, what's the consistency? Does it float on top of the water more than it should? Is it hard to flush? I mean, there's a million different questions you learn as a, as a medical student and you're like this poop detective when people come in with issues. And so it's, uh, it's funny, I guess, you know, in the exam room with the doctor-patient relationship, there's sort of no barriers, you know, you talk about everything and you're talking about the most intimate details of a person's life, even though you just met them a second ago. It's so different than normal social interactions, yet there is this social aspect. A lot of what I do is social, you know, it seems like doctors, what they do is mostly scientific, but actually, it's just relating to another person and you have to re- maintain, you know, your professional demeanor and this normal human level interaction, even though you're talking about poop. Um, and that's a skill, that's an art and a science.
- LFLex Fridman
Well, okay, actually I want to linger on that because I'm a fan of just diving into conversations right away with strangers. Just getting... No small talk. And this is like the ultimate... I don't know if it's the ultimate, but it's one version of no small talk. You get right to the point. I, um...
- 1:04:18 – 1:12:09
Emergency room
- LFLex Fridman
That's really powerful from a psychology perspective. You're a kind of therapist or you have the power to be a therapist. No- I don't mean just about the medical condition of the body, but the psychological. There's so much fear connected, uh, to, to this concern. Also, uh, self-doubt, um, insecurities, even, uh, sort of existential thoughts about your mortality. All those things are right there in the room. Um, so I think one way doctors deal with that is they kind of have this cold way about them. They, they almost have like dual mode. One is like, I'm going to be friendly on the surface and cold about the brutal honesty of the biology. But I wonder if there's like, um, a skillful middle ground, this dangerous place where you can help people deal with their psychological insecurities, concerns, fears, all those kinds of things. Is that just really tough to do?
- JRJonathan Reisman
Yeah, and it's- it's a huge part of being a doctor is, is dealing with the psychological aspects of whatever's going on with the patient's body. I mean, in the ER, you deal with psychiatric emergencies kind of left and right more than ever these days, and, um, you know, that's a huge issue. Not to mention sort of drug use, alcohol-related stuff, you know, that gets into sort of psychology and the human love of intoxicants and changing the brain's chemistry. Um, and, you know, and habit, of course, we're creatures of habit and that plays in as well. I mean, a big part of, for instance, pediatrics is reassuring parents and kind of convincing them, giving them the confidence that what's going on with their child is not serious, will go away on its own, does not need any particular intervention. Um, and- but adults too, you know, reassurance is a huge part of the game. Um, yeah, you know, in the ER, you see humanity at its most raw. I feel like you get this tremendous insight into people, how they live, what they worry about, what they think about, how their body works, and also how their mind works that you almost don't see anywhere else. It's a really interesting, um, place to work. And also our- the way our society is shaped, the ER is where people go for almost everything. When they're suicidal, they come to the ER. When they're too high on drugs to walk, they come to the ER. You know, children who have been abused, sexually abused, physically abused, come to the ER for us to investigate. Uh, it's sort of like the, the all-purpose waste bin for the dregs of society, what people do to themselves and what they do to other people. You know, you mentioned you're interested in the darkness of humanity, it made me think of the ER where you really see, uh, what human life is like, um, in the ER.
- LFLex Fridman
(laughs) Okay, you've, uh, you tweet about, you write about, you think about the emergency room, ER. That's really fascinating. Just a little window you, uh, give to that world is fascinating. What lessons about humanity do you draw from this place where you're so near to death? There's so much chaos. There's so much variety of what's wrong, so little information.... um, or the, the, the urgent nature of the information inflow is such that you can't really reason sort of thoroughly and deeply and collect all the data and all those kinds of things. You have to act fast, and then everybody's freaking out. Can you just speak to the human condition, uh, (laughs) that you get a glimpse at through the ER experience?
- JRJonathan Reisman
Yeah, I think y- you do see all those things. I think on, on one end of the spectrum, it is this very unique place where you get all these unique insights. On the other end, it can become a ho-hum workplace just like any other-
- LFLex Fridman
(laughs)
- JRJonathan Reisman
... which is sort of surprising. As I mentioned before, humans seem to be able to get used to almost anything, and doctors can get ho-hum used to, oh, dying of a heart attack, oh, actively in labor and the baby's half out, oh, you know, just ho-hum, "I know what to do going about my job and go home and have dinner with my family and not think too much about it." That's amazing. I do, I do try to, um, maintain, you know, both my fascination, you know, as I think writers in general tend to think more about what they see, write more about what they see, maybe draw connections with what they see to other things. So, I do think that writer's perspective does help me, uh, kind of maintain my fascination and my kinda more of an insightful perspective than just a ho-hum water cooler conversation. Um, but you do see a lot, you know, um, in a way, medical problems are sort of the great equalizer, right? Um, class, race, culture, background, you know, the failings of the human body, the way it fails, and what we can do to help in those situations is almost universal. I always like this quote from, you know, Chekhov was a doctor and a writer, and he, uh, saw, t- treated a lot of, uh, peasants, very low class, and also treated a lot of aristocrats. And he, he wrote that they all have the same ugly bodies, basically, which I think is really, uh, right on. And, you know, it's sort of you can see people underneath a superficial layer of clothing, maybe it's the most expensive clothing bought from the fanciest places, but underneath, their body is still failing in the same way, and they still have the same anxieties, the same worry about mortality, the same concerns about why their poop turned green today (laughs) , um, all these things that they bring to the table. So, in a way, it is this great equalizer, um, where, where people are kind of all the same in some ways.
- LFLex Fridman
Yeah, I feel like people sometimes ... Class, money, fame, power makes you for a time forget that you're just a, a meat vehicle, and, um, and j- just as good and just as bad as the other meat vehicles, uh, all around you. In that sense, um, there's this question sometimes raised, are some people better than others? And I usually answer no to that question because of that. Yeah, some people might be better at math. Some people might be better at music, but at the end, we're just meat bags, beautiful as we are. There's a poem that just, uh ... A small tangent I wanna take. I just, uh, saw it, Just Acting, f- that you have, uh, written. I have to, um ... Would you classify it as a poem?
- JRJonathan Reisman
Yeah.
- LFLex Fridman
"At first ..." If I may read it. "At first, you enter the clinic, shoulders weighed down by white coat, pockets book-stuffed. Timid, you act out a role, your white coat a costume, your questions a script, your demeanor a rehearsed act. No one is going to buy this. But then, as you play the role again and again, repeating the lines and motions, the script slowly dissolves and the interaction becomes thoughtless, and the rehearsed act slowly fades into a profession. You suddenly find yourself unable to tell if you're still acting or if you're doing it for real. And now, you're a doctor. Jonathan Reisman, MD, Harvard, Massachusetts General Hospital Medicine and Pediatrics Department." Beautiful. So, that is what it is to be a doctor. You're just acting. Fake it till you make it.
- JRJonathan Reisman
Exactly. Fake it till you make it. And I think ... I imagine every medical student has this feeling when they first go into a room, like I talked about asking this nice old lady about the color of her poop for the first time, and you're just like, "What am I doing here?" Like, "What does ... Does she believe I'm a doctor? You know, this just feels absurd." But then it's, again, ho-hum, becomes normal.
- 1:12:09 – 1:17:14
Sperm
- JRJonathan Reisman
- LFLex Fridman
Now, there's not a sperm chapter in your book. This, uh ... You mentioned offline that this is a second and a third book that you're working on, all about sperm. No, I'm just kidding. Um, but ... Or maybe (laughs) I'm not. (laughs) Uh, humor tends to make way for reality. Um, so the, the tweet was that a human, an average human male produces 500 billion sperm, I believe, which is about four to five times more than, uh, the number of people who have ever lived, and each of those sperm is genetically unique. So, you can think of them, you can kind of imagine the possible humans they could have created, and they're all different. Uh, they have similarities, of course, but they have peculiarities that are ... Make them different. And you can think of all the different trajectories, all the Einsteins, the Feynmans, the Hitlers, um, and all the people who have died, who would have died during childbirth, who would have died early in their years given the different diseases. It's, it's fascinating to think about an average human. (laughs) Yeah, we're all winners of a very competitive race. So, the people who make it, we're, we're winners. #winning. Um, is there something that you find, uh, fascinating, interesting, beautiful, ugly, surprising about sperm?
- JRJonathan Reisman
I think sperm is, um, yes, it is an, a very interesting bodily fluid. Maybe I'll write about it in a second or third book. We'll see. But, uh, you know, I guess sperm is interesting because it's kind of the only projectile bodily fluid, um, from the body. Um, you know, vomit can be projectile. Usually that's a diseased state. That's not the expected kind of normal, healthy state.
- LFLex Fridman
Oh, sneezing? Would you classify that or no?
- JRJonathan Reisman
True. I guess there's, it's, yeah, there's some particles in the air. I guess it's not a fluid. I mean, not a liquid. Um, but true. I mean, cough in addition to sneeze, right? Sneeze is how our nose gets rid of something that shouldn't be there. Cough is how our lungs get rid of something that shouldn't be there. Vomiting is sometimes how our stomachs get rid of something that shouldn't be there. All projectile, sometimes in their own way. Sperm is sort of interesting. It's created with the food for its journey. Sperm mostly feed off of fructose, a kind of sugar, um, you know, for the few days that they live inside the female genital tract. But it's sort of a... I like comparing our genitals to the genitals of the plant world, which is flowers. And in the same way that, uh, you know, a touch me not, uh, for instance, the kind of flower where when you brush up against it, it sort of launches seeds into the distance to try to, um, survive in a way, kind of the sperm is doing something similar, launched into the female genital tract and then all, all trying to find this, uh, competing against each other to find this egg. It's really amazing when... And when you learn about it from the biological perspective, the most amazing thing is how many things can go wrong, um, you know, just in the sperm not surviving long enough for it making it to the egg and then some genetic, um, abnormality causing a miscarriage. Uh, it's sort of astounding that it works as often as it does, and I think the lesson there is just that people have a lot of sex, and so statistics just favor it's gonna work out a good number of times.
- LFLex Fridman
Yeah, and there might be intelligence in the design of just the sheer number of sperm. Maybe that's yet another way to inject variety into the system.
- JRJonathan Reisman
And redundancy, I guess, you know. We have two kidneys. We have two hands. If we lose one, we can still go on. We have, you know, m- how many, however many millions of sperm get sort of launched in every ejaculation is a... You know, if a bunch fail or don't make it inside, others will.
- LFLex Fridman
There's papers on this, by the way, uh, that I read for some reason. Not read, but skimmed for some reason, which is, uh, talking about which sperm usually wins. Like, what are the characteristics of sperms that are winning? And it's not the fastest. So it's appa- (laughs)
- JRJonathan Reisman
(laughs)
- LFLex Fridman
Apparently, there's some kinda slaughter that happens early on. People will correct me. But it's not the fastest. It's, there is a aspect of it's the luckiest. It really is-
- JRJonathan Reisman
Hmm.
- LFLex Fridman
... like the body tries to make it a random selection. It tries to make it fair in making it as random as possible. Interesting, and also interesting that they're fueled by fructose. I didn't really think about that. So they're a, um, they're a carb-loaded athlete.
- JRJonathan Reisman
Right, with food for the journey.
- LFLex Fridman
Food for the journey, 'cause I'm, I'm somebody that actually does a lot of running on, um, I, I guess you would call me a fat-adapted athlete, so I do a v- sort of meat-heavy diet. And so you could do a lot of endurance kind of stuff when you don't eat any carbs, any glucose, any of that kind of stuff, a- and you are very low. It's interesting to think that sperm are like, "Nope." They're total bros who just go to the gym-
- JRJonathan Reisman
(laughs)
- LFLex Fridman
... uh, sprint performance. Short-term performance is everything. All right. Well, that's
- 1:17:14 – 1:22:43
Liver
- LFLex Fridman
sperm. Turning to the liver, the place that deals with all our poor decisions. No, um-
- JRJonathan Reisman
Many of them.
- LFLex Fridman
... many of our poor decisions. Is there, um... You said that the liver does, uh, quite a few things. Uh, what to you is fascinating and beautiful about the liver?
- JRJonathan Reisman
I would say its primary function seems to be as the sort of gatekeeper for what we eat and absorb. Um, you know, the entire gastrointestinal tract from the esophagus to the rectum, the blood flows from it not back to the heart, but to the liver where it's first examined, kind of things are evaluated, packaged, uh, you know, processed, detoxified perhaps, and it's kinda this great overseer of what we digest and absorb. And so it kinda keeps, um, keeps track of, of, of what's coming in, you know, the outside world that comes in and become, will become part of us. You know, why the, that's why partly the liver suffers sometimes the injury from, uh, certain, certain toxins like alcohol. But beyond that, the liver is also the place, as I said, it metabolizes things too, so it metabolizes alcohol and why it can be injured by alcohol, it metabolizes drugs like Tylenol, which is why Tylenol is, uh, can be, uh, very toxic to the liver when taken as an overdose. Um, so the liver, you know, even beyond that, the liver produces a lot of different, uh, you know, things that float in the bloodstream. It packages, uh, cholesterol and fats and sends them to where they're needed. It deals with protein in the blood. It deals with clotting factors in the blood, helping the blood clot. Um, you know, processes things like bilirubin and other things that really, as I mentioned, is like 15 organs wrapped into one. Maybe that's why it's sort of the biggest internal organ. The skin's bigger, but it's not an internal organ.
- LFLex Fridman
Right. The biggest organ in the human body is the s- the skin.
- JRJonathan Reisman
Right. But the liver's the biggest internal organ, and it really is a powerhouse and, and does a lot, which is why when people suffer from liver failure, kinda everything goes wrong in a way.
- LFLex Fridman
And, uh, in terms of replacing organs, what, what are organs that are easily replaceable, which are not? Like, on the list of things that are hard to replace and not, wh- what would you put at number one? What would you put at, like, at the bottom?
- JRJonathan Reisman
Well, I'd say the kidneys are... You know, nothing's easy, but kidneys are easiest in a way. Partly, I mean, maybe a big factor there is that other people have two of them and can give one to you, so you don't have to wait for people to die, which is the case with hearts and livers.... sometimes you can take a part of a liver from someone who's a- alive. And the liver does have this kind of, uh, mythological ability to regenerate itself.
- LFLex Fridman
Mm-hmm.
- JRJonathan Reisman
Um, in the myth of Promethe- Prometheus, he's, you know, chained to a rock and the bird eats his liver every day and it grows back every day, and that's, uh, actually biologically accurate. It do- not that he can completely get rid of it and it'll appear again, but when pieces of it are removed or injured, it does regenerate itself pretty amazingly. Um, so I'd say the kidneys, the fact that there are more around. Um, also it's, you know, the kidney's a smaller organ. It's often just, you don't have to put a transplanted kidney where the kidney should be in the back of the abdomen. You can just kind of stuff it into the pelvis there 'cause it's a smaller organ. The liver would be hard 'cause it's huge. Um, and I, I guess we just have the most experience with kidney transplants 'cause they are the most common.
Episode duration: 2:43:51
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