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Anatomical quirks: 10 things you didn't know about your body
Bill Bryson's new book, "The Body: A Guide For Occupants," provides important (and funny) lessons in anatomy, neuroscience, physiology, biology, and more.
- American-British scholar, Bill Bryson, has written a fascinating user's guide to the human body.
- The Body: A Guide For Occupants provides important lessons in anatomy, neuroscience, physiology, biology, and more.
- Though we've learn a lot about ourselves in the last two centuries, it's still clear there's much we don't know.
As far as medicine and science have come, we remain ignorant of much of how our body functions. It's a challenge for us, for instance, to wrap our heads around the ecosystems that live within us — that are us. Indeed, even for the self-aware animal that we are, we're still in a nascent phase of understanding what we really are.
That's why we need writers like Bill Bryson. His new book, The Body: A Guide for Occupants, continues the American-British scholar's quest to understand nearly everything — as evidenced by his 2004 book, A Short History of Nearly Everything. Most well-known for travel books such as A Walk in the Woods and Notes From a Small Island, Bryson's nonfiction writing is as enjoyable as his journals galavanting around the globe — not nearly as humorous, but he lets plenty of quips slip into this latest work as well.
Below are 10 factoids about yourself (and, more generally, our species) that you might not have known. If only this book had been available during my high school years, I might have retained more than I did than with those dry biology textbooks. Educators, take note.
To hear Bryson explore his new work, make sure to check out a recent episode of our podcast, Think Again.
Bill Bryson, travel writer, at the Cheltenham Literature Festival on October 10, 2015 in Cheltenham, England.
Photo credit: David Levenson / Getty Images
The Resistance is Growing
Much of our stomach bacteria is healthy, yet for a multitude of reasons our gut ecosystem is becoming infertile. First off, we owe Scottish biologist Alexander Fleming a note of thanks for discovering penicillin, which immediately saved millions of lives. Yet, even in 1945 he warned of the dangers of microbes growing a resistance to this newly discovered medicine known as antibiotics.
As Bryson writes, from the 1950s through the '90s, three new antibiotics were introduced in the U.S. every year; now the number is one every other year. Sadly, pharmaceutical companies would rather focus on drugs that people need to take for decades (like statins and SSRIs) than on low moneymakers that will be obsolete in a few years.
Overuse fattening up farmed animals, C-sections (in which the baby does not pass through the wash of microbes in the mother's vagina), and our own misuse all seem to blame. For example, 20 percent of all antibiotic usage is for sinus problems, yet antibiotics do not help sinus problems. Bryson continues, "Almost three-quarters of the 40 million antibiotic prescriptions written each year in the United Stats are for conditions that cannot be cured with antibiotics."
The human brain is hungry. Weighing just 2 percent of our body weight, it consumes 20 percent of our energy requirements. Whether you're watching TV or doing complex math, your brain burns roughly 400 calories every day. Thinking more doesn't result in a greater calorie burn. In fact, the opposite is true.
"An academic at the University of California at Irvine named Richard Haier used positron emission tomography scanners to find that the hardest-working brains are usually the least productive. The most efficient brains, he found, were those that could save a task quickly and then go into a kind of standby mode."
Our vestibular system is responsible for balance. Located inside of our ears, a gel informs our brains whether we are going left or right, up or down. When spinning in a circle, the gel keeps moving when we stop, resulting in that peculiar disorientation children seem to love. Fascinatingly, our brain isn't interpreting it as merely a pause.
"When loss of balance is prolonged or severe, the brain doesn't know quite what to make of it and interprets it as poisoning. That is why loss of balance so generally results in nausea."
Over the course of your life, you'll secrete roughly 31,700 quarts of saliva. In an interesting comparison, Bryson notes that this is equivalent to "two hundred or so deep baths." As I recently wrote about, salivary diagnostics is an important developing field of medicine. A recent discovery, Bryson writes, is opiorphin, a natural painkiller produced by our saliva. While six times more potent than morphine, we produce very little amounts of it — not enough to avoid the pain of hot pizza on the roof of your mouth, but still, an essential biological feature that helps us manage pain.
Pain in the Head
Speaking of pain management, only our brain — an organ that itself cannot feel pain — can feel pain. Headaches are not even our brain hurting, regardless of how deeply we feel it. Of all the various types of pain there are, some confer evolutionary benefit by warning you to avoid something while others seem to be a design failure. For example, we usually don't feel the pain of cancer until after it's already ravaged our body. Not much of a warning system, that one.
There is not much of a difference between physical and emotional pain. Both can be diminished through a variety of means, such as "pleasant aromas, soothing images, pleasurable music, good food, and sex." Another important factor is expectation. Bryson concludes, "In many ways, we feel the pain we expect to feel."
Bill Bryson on the miraculous human body
Younger is Not Better
Up until relatively recently, children went through puberty around age 16 or 17. That dropped drastically in the last century due to improved nutrition. There's a problem, however: young girls are now menstruating as early as seven or eight, and there is a link between excess estrogen and cancer later in life. You solve one problem — in this case, malnutrition — and suddenly others appear.
While there is no clear reason why we develop allergies at all, between 10 to 40 percent of the world's populations suffer an allergy to something. Strangely, the richer the nation, the more allergies its citizens get. While there is a genetic link, it's only an increased chance that you'll get what your parents have (about 40 percent). Genes are not destiny, unless they are.
One thing is certain, however: babies born through a C-section are eight times more likely to develop allergies (as well as more likely to be struck with diabetes, asthma, celiac disease, and obesity). Today, 60 percent of all births through C-section are because of convenience, not necessity. There's a reason babies are born the way they are. By not allowing for that (unless medically necessary), we're doing our children more harm than the temporary good of reduced pain during childbirth.
Stop Eating So Damn Much
In 1915, an average American spent half of their weekly income on food. Today that number is closer to 6 percent, yet we're eating more than ever. As our biology dictates a hoarding mentality, health care systems pay the price, mostly due to processed foods (almost all of which contain added sugars). As Bryson puts it, "We are in the historically extraordinary position that far more people on Earth suffer from obesity than from hunger."
That Said, Weight Isn't Everything
We know that obesity creates many health problems, but a hyper-focus on "clean eating" and a holistic lifestyle doesn't mean you're going to avoid all of biology's ills.
"Roughly 40 percent of people with diabetes, chronic hypertension, or cardiovascular disease were fit as a fiddle before they got ill, and roughly 20 percent of people who are severely overweight live to a ripe old age without ever doing anything about it."
The body is certainly confusing.
Finally, A Few Myths
It's incredible how easily swayed we are. For example, in 1968 a doctor published a letter (not a study or research) describing how uneasy he felt after dining in Chinese restaurants. He speculated that MSG might be the cause. It wasn't, but for decades we've labeled it as toxic. It's not; it's an essential component of the glorious taste sensation, umami.
Genetically speaking, humans don't reproduce. We recombine.
The marketing ploy that has men taking testosterone supplements to stave off the natural 1 percent yearly decline starting in their '40s? Putting it back in is more likely to harm you: men increase their risk of a heart attack or stroke by taking these supplements.
Ten thousand steps a day? That myth is based on a single study done in Japan in the 1960s that was on shaky ground to begin with. This said, you should be walking. Ten thousand is roughly equivalent to five miles; studies of hunting and gathering societies, which are comprised of generally fit populations, have a "slightly" higher average: 19 miles per day.
Sleep is for the consolidation and transferring of memories? Maybe.
Finally, we don't lose most of our body heat through our heads. Body heat is evenly distributed. If you walk out in winter without a hat, however, you are risking losing body heat through that area because it's exposed. Listen to your mom and put on a hat, dummy.
Sallie Krawcheck and Bob Kulhan will be talking money, jobs, and how the pandemic will disproportionally affect women's finances.
A neuroscientist argues that da Vinci shared a disorder with Picasso and Rembrandt.
- A neuroscientist at the City University of London proposes that Leonardo da Vinci may have had exotropia, allowing him to see the world with impaired depth perception.
- If true, it means that Da Vinci would have been able to see the images he wanted to paint as they would have appeared on a flat surface.
- The finding reminds us that sometimes looking at the world in a different way can have fantastic results.
The study<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODc3Mjc2NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MTA4MDg2NH0.T-98YvLjS9mUCQkgqHyV43Q7h_JIiubrev-Fp_0j4Pg/img.jpg?width=1245&coordinates=0%2C38%2C0%2C579&height=700" id="58346" class="rm-shortcode" data-rm-shortcode-id="674799ba34e115a2e9a3e94c366bfc26" data-rm-shortcode-name="rebelmouse-image" />
The Virtuvian Man. Christopher Tyler suggests that Da Vinci used his own image as a template for the face in the drawing.
Vitruvian Man, by Leonardo da Vinci created c. 1480–1490<p><a href="https://www.city.ac.uk/people/academics/christopher-tyler" target="_blank">Professor Christopher Tyler</a> of the City University of London's optometry division analyzed six pieces of Renaissance art by or held to be images of Da Vinci, including the famous <em>Vitruvian Man. </em>By looking at the paintings, drawings, and statues and applying the same techniques optometrists use on patients, Tyler was able to conclude that the eyes of the men depicted were misaligned.</p><p> He concluded that, if the images he analyzed were truly reflective of how Da Vinci looked, that the great artist had a mild case of exotropia. </p>
How would this have helped him paint?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="b221010aa7688734d4d6a41f0df5933f"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/j6F-sHhmfrY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><a href="https://shileyeye.ucsd.edu/faculty/shira-robbins" target="_blank">Shira Robbins</a>, a professor of ophthalmology at the University of California at San Diego, who was not involved with the project, explained to <em><a href="https://www.washingtonpost.com/news/morning-mix/wp/2018/10/19/leonardo-da-vincis-genius-may-be-rooted-in-a-common-eye-disorder-new-study-says/?utm_term=.d3f44ed91c16" target="_blank">The Washington Post</a> </em>how individuals with exotropia often turn to additional information to help understand the world around them:</p><blockquote>"What happens in some people is when they're only using one eye . . . they develop other cues besides traditional depth perception to understand where things are in space, looking at color and shadow in a way that most of us who use both eyes at a time don't really appreciate." </blockquote><p>Dr. Robbins agrees that, if the artworks analyzed accurately depict Da Vinci, then he probably had exotropia.</p><p>If Da Vinci did have a mild form of the condition, which would allow him to focus with both eyes when concentrating and with one when relaxed, Tyler asserts that the famed artist could have viewed the world in two or three dimensions at will, showing him the world exactly as he would need to recreate it on a flat surface. Quite the superpower for an artist.</p>
Does this mean Da Vinci would have been a hack if he had normal eyesight?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODc3MjY5NS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYyMjYwOTgxOH0.eSu3YBpCuaDj59-4lzSeZ1WgwtV2ETGiWHqczzW3how/img.png?width=980" id="9c323" class="rm-shortcode" data-rm-shortcode-id="edd4e9e9d9c1156a53242df6288d7cc0" data-rm-shortcode-name="rebelmouse-image" />
A graph showing the difference in where each eye is focused for each painting, drawing, and statue used in the study. The larger the difference, the more pronounced the exotropia is in the image.<p>Not at all. What Dr. Tyler is suggesting is that the tendency of people who have exotropia to rely on using one eye to see the world and thereby lose some depth perception allowed Da Vinci to understand better how the three-dimensional objects in the world could be translated into a two-dimensional image on a canvas. This could account for some of Da Vinci's skill in depicting shadow and subtle changes in color, since he would have relied on these details to understand the world. <br><br>His polymathic brilliance extended far beyond art, and nobody is claiming that his ideas for flying machines, tanks, or <a href="http://www.da-vinci-inventions.com/davinci-inventions.aspx" target="_blank">other inventions </a>were at all influenced by a vision problem.</p>
How can we know this? He has been dead for five hundred years.<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="c26fc51b0aebbcd6905593015fec79e5"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/LRAptNtN9-A?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>There are reasons to be cautious anytime we make claims about people who are long dead. In this case, we have the bonus problem that we aren't 100 percent sure that the images used are supposed to look like Da Vinci. </p><p> That is the major caveat of the idea; all of the images used as evidence of his condition are assumed to look like him. While some of the images, like the <a href="https://en.wikipedia.org/wiki/David_(Verrocchio)" target="_blank"><em>David</em> by Andrea del Verrocchio</a>, are generally agreed to be based on Leonardo the other pictures are claimed to be reflective of him based only on his statement that "[The soul] guides the painter's arm and makes him reproduce himself, since it appears to the soul that this is the best way to represent a human being." </p><p>Tyler also argues that the portraits he claims are based on Da Vinci share similarities with the images generally accepted to be portraits of him; including similar hair and facial features. This lends weight to the idea that the artist incorporated his own traits into his artwork, including his vision problem. </p><p>Leonardo da Vinci was undoubtedly one of the greatest geniuses of all time. If he had exotropia, then it was merely a minor addition to his artistic skills. It does, however, give us a literal example of how people who look at the world differently can use that vantage point to their advantage to create things we all can appreciate. </p>
Want help raising your kids? Spend more time at church, says new study.
- Religious people tend to have more children than secular people, but why remains unknown.
- A new study suggests that the social circles provided by regular church going make raising kids easier.
- Conversely, having a large secular social group made women less likely to have children.
Be fruitful and multiply<p>Scientists in the United Kingdom collected data on more than 13,000 mothers and their children. Most of them were religious, but 12 percent were not. The data included information on their church habits, social networks, number of children, and the scores those children achieved on a standardized test.</p><p>In line with previous findings that religious women have more children than secular women in industrialized countries, a connection between at least monthly church attendance and fertility was confirmed. However, religious parents showed they could avoid the pitfalls that having more children can bring. </p><p>Typically, more children in a family leads to reduced cognitive ability and height in each <a href="https://academic.oup.com/ije/article/37/6/1408/729795" target="_blank">child</a>. Some studies find that children do less well in school for each <a href="https://link.springer.com/article/10.1007/s13524-016-0471-0" target="_blank">additional sibling they have</a>. This makes a kind of intuitive sense, as parents with more children would have to divide their time, energy, and resources among more people as families expand. One would expect that the larger families would also lead to things like lower test scores. </p><p>Despite the expectation, the children of religious parents didn't have lower scores on standardized tests. There were small positive relationships between the size of the mother's social network, the number of co-religionists helping out, and the children's test scores. However, this association was small, didn't show up in all of the testings, and was unrelated to other variables. </p> These effects might be explained by the size and helpfulness of the social networks around the more religious. Women who went to church at least once a month had more extensive social networks than those who never go or who attend yearly. These social networks of co-religious people mean that there are more people to turn to for help with child-rearing, a point also demonstrated in the data. The amount of aid women got from their fellow churchgoers was also associated with a higher fertility rate. <br> <br> Conversely, an extensive social network was associated with fewer children for secular women. This finding is in line with <a href="https://journals.sagepub.com/doi/10.1207/s15327957pspr0904_5" target="_blank">previous studies</a> and suggests that the social networks comprised of co-religious individuals differ from those found elsewhere.
So, how quickly should I join a local religious group?<div class="rm-shortcode" data-media_id="6RrmYM8M" data-player_id="FvQKszTI" data-rm-shortcode-id="9eb4740a7d1e10108a75fd2ed627a90f"> <div id="botr_6RrmYM8M_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/6RrmYM8M-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/6RrmYM8M-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/6RrmYM8M-FvQKszTI.js"></script> </div> <p>The study is not without its faults, and more investigations into the relationship between fertility, childcare, ritual, and social networks are needed.</p><p>These findings all show correlation, not causation. Though it might be said the results point towards causation, various alternative interpretations of the data are apparent. The authors note that most religions are explicitly pro-natal. It is possible that religious women have internalized these values and simply choose to have more children than secular women do.</p><p>This idea is similar to a potential interpretation of why large social networks have the opposite effect for secular women. The authors suggest that, in some cases, these more extensive social networks are associated with work and exert an anti-natal influence. Again, the people who build such networks may be people unlikely to have large families under any circumstances.</p><p>However, the researchers' hypothesis endured. The help religious women get from their church-based social networks allows them to have larger families than those who lack these support systems. In some instances, these support systems also prevent the adverse effects of larger families. </p>
The community religion offers<p>As we've mentioned <a href="https://bigthink.com/culture-religion/what-is-secular-humanism" target="_blank">before</a>, religion offers a community, and a community provides social capital. As religion continues to decline in the West, the social bonds of faith communities that used to tie social communities together begin to decay. However, as has been noted by a variety of observers for the last few decades, fewer and fewer new organizations appear ready to replace religion as a source of community in our lives.</p><p>While many different organizations might offer social support that religion once provided the whole of western society, this study shows that different social circles can differently affect the people in them. This finding must be considered by those trying to find new communities to join or the authors of future research. </p><p>The community offered by religious groups provides real benefits to those who join them. As this study shows, having the support network religious community offers allows some parents to avoid pitfalls that bedevil those lacking similar support. It suggests that previous studies demonstrating that group ritual offers benefits like increased amounts of <a href="https://journals.sagepub.com/doi/10.1177/0956797612472910" target="_blank">group trust</a> and <a href="https://journals.sagepub.com/doi/10.1177/1069397103037002003" target="_blank">cooperation</a> are onto something and that those benefits have a variety of applications. </p><p>While this study is not without its blind spots, it offers a strong starting point for further investigations into the nature of ritual in our modern lives and how local support networks remain vital in our increasingly globalized world. </p>
Health officials in China reported that a man was infected with bubonic plague, the infectious disease that caused the Black Death.
- The case was reported in the city of Bayannur, which has issued a level-three plague prevention warning.
- Modern antibiotics can effectively treat bubonic plague, which spreads mainly by fleas.
- Chinese health officials are also monitoring a newly discovered type of swine flu that has the potential to develop into a pandemic virus.
Bacteria under microscope
needpix.com<p>Today, bubonic plague can be treated effectively with antibiotics.</p><p style="margin-left: 20px;">"Unlike in the 14th century, we now have an understanding of how this disease is transmitted," Dr. Shanthi Kappagoda, an infectious disease physician at Stanford Health Care, told <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">Healthline</a>. "We know how to prevent it — avoid handling sick or dead animals in areas where there is transmission. We are also able to treat patients who are infected with effective antibiotics, and can give antibiotics to people who may have been exposed to the bacteria [and] prevent them [from] getting sick."</p>
This plague patient is displaying a swollen, ruptured inguinal lymph node, or buboe.
Centers for Disease Control and Prevention<p>Still, hundreds of people develop bubonic plague every year. In the U.S., a handful of cases occur annually, particularly in New Mexico, Arizona and Colorado, <a href="https://www.cdc.gov/plague/faq/index.html" target="_blank">where habitats allow the bacteria to spread more easily among wild rodent populations</a>. But these cases are very rare, mainly because you need to be in close contact with rodents in order to get infected. And though plague can spread from human to human, this <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">only occurs with pneumonic plague</a>, and transmission is also rare.</p>