Posts Tagged 'Anatomy'

Who died?

I’m not dead. Just took a couple weeks off of writing anything. I’ll spare you the litany of excuses. That’s not why you’re here. But I’ll let you know what I’ve been doing to get you up to speed before I return to celebrity bashing and book reports on science news.

A lot has been going on lately, professionally and personally. I’ve been struggling to get my lectures together for the spring semester. It’s all new stuff that I’ve never taught before so my self-doubt has turned into wicked procrastination. I’ve finally turned a corner on it though and I should be able to meet my printing deadline. It’s ridiculous that I have to have all of my lecture materials prepared months before I’m going to give them, just so they can make a billion copies for the students. Where’s the spontaneity and energy in something that overly prepared? tongue-deep-dissectionAnyway, what I’m teaching is the neuroanatomy component of the dental gross anatomy course (The image at right is from Grant’s Atlas of Anatomy, 11th edition, Agur and Dalley editors, LWW* citation added 3-18-2011). I’m pretty psyched about the subject. The muscles and bones of the body are interesting, but the nervous system is how it all actually works so you can go a lot deeper into the meaning of the anatomy. I think it will be alright if I can just strap myself down to my desk and finish this shit.

I started piano lessons again. It’s been almost ten years since I last took lessons at Concordia. It’s fantastic to be in it again. I’ve been playing quite a bit in the last ten years thanks to a very productive collaboration with a friend who is a great singer. We spent a few years making music together – stuff from all genres of the musical world, except gangsta rap and bluegrass. When she moved last year, that marked the unofficial end of my standing accompanying gig, so I thought that whenever I got my shit together, maybe I’d take lessons again and try to take myself to another level with the instrument. I never did actually get my metaphorical shit together, but J and I got a house and a pretty nice rhythm to our lives, so there suddenly seemed to be room for something else – something just for me.

It just so happened that J was working with a gal who teaches piano professionally (she works at the blood gardens in the mornings for extra cash). She was taking new students, J mentioned that I played and had been thinking about taking lessons again, next thing you know, I’m talking Bach with her over a pair of grand pianos in her home.

A big part of why I wanted to give this a try again was that I feel like I’ve changed so much in the last 8 years and I wanted to find out if I could approach the piano with a different perspective and be more successful with it. I think I’ve always had talent and a good musical ear, but problems in the motivation department. Part of me wondered if my growth and maturity as a scholar and teacher would make me a better student and a harder worker. Also, could my extreme knowledge of the musculoskeletal anatomy of the hands and the neurological pathways behind learning somehow help me think about the instrument and learning new music in a entirely different way? So far, I think the answer to all of the questions is yes. I’ve had more fun practicing the last few weeks than I think I’ve ever had preparing for lessons in years past. I don’t think I’ve been at it long enough to know if I’m actually getting way better or not, but in terms of sheer enjoyment, it’s a great success.

So that’s what’s new with me. Expect some excellent social commentary soon. I’m kind of over the whole election thing, so forgive me if I don’t weigh in on that one. Thanks for reading. Below is a quiz for all you pianists and anatomists out there. Which images represent which thumb movements – Abduction, Adduction, Flexion, Extension, Opposition?  Which movements are used in the passing under of the thumb in scales and long passages?pop quiz hot shot

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Ticklish?

Today for lunch, I decided to figure out what it means to be ticklish. I’ve always been curious about it. I’m not super ticklish, but I can remember more than one time laughing so hard from tickling that it hurt. Over the last few days, I have been thinking about laughing and thought about writing about the biology/anatomy of laughing but it just became too big of a story for the amount of time I had today. So tickling it is.

First of all, there’s two kinds of tickling: knismesis, which is the weird ticklishness you get when someone lightly strokes your skin, or a bug is crawling on your skin, and gargalesis, which is the full-on crazy ticklishness most people have in their armpits and soles of the feet. Gargalesis is also my new favorite word. Although the sensations are similar, the mechanisms behind them seem to be very different.

Knismesis is theorized to be a serve as a protective function of the skin, alerting the organism that something foreign is on the body. The sensation is mediated by neurons that mediate pain and neurons that mediate touch, so in cases where one type of nerve modality is damaged or removed, ticklishness can still remain although in a weaker sense. In general, this type of tickling does not result in laughter. You can induce the knismesis response in yourself if you lightly rub the roof of your mouth with your finger. Careful when you do it though, it’s kind of intense. This type of ticklishness has also been well-documented in animals, and widely studied in cats.

Gargalesis is similar to knismesis in that the same neurons seem to be activated in response to the “heavy tickling” stimulus as were activated by a “light feather” stimulus. However, it is different from knismesis in that it is found only in specific sites of the body. The most common sites are the armpits, soles of the feet, sides of the torso and ribs, neck and knee. Gargalesis is also different from knismesis in that it is generally not possible to induce the response on yourself. I think that’s pretty obvious to most people. When you wash your armpits in the shower you don’t laugh hysterically. At least I don’t. However, the issue is more complicated than that. In studies where subjects used a joystick to operate a tickling robot on themselves, researchers found that the subjects did not laugh in response to tickling. So, even though the tickling stimulus was coming from somewhere else, simply anticipating the stimulus is enough to dampen the response. The cerebellum seems to be the source of this cancellation of self-produced gargalesis. Conversely, if subjects were blindfolded and the tickling robot was operated by someone else, they would respond with laughter as though they were being authentically tickled by a person (so it’s not just that the robot sucks as a tickler). I tried in vain to find an image of the tickling robot used in these studies but I’m not sure it exists on the web, so until I find it, I’m going to assume it looks like this:

So what’s the use of gargalesis? There are several popular theories but no one knows for sure why. One theory suggests that it is a defense mechanism, since most of the commonly ticklish areas are areas of particular vulnerability to injury during hand-to-hand combat. The reflexive pulling-away that most people get during tickling would be a boon to survival. Another theory suggests that maybe the ticklish spots developed in utero and were used as a means to reflexively orient the fetus’ body correctly in the womb. Yet another theory posits that tickling is in fact rooted in the need for social connection and rough play during early development. The laughing and smiling reflex to tickling serves to encourage the tickler to continue.  Most people’s first experiences with tickling are with their mothers, maybe ticklishness is a way to enhance the mother-child bond. Of course at the end of the day, these are only theories and no one really knows for sure why it exists.

It is interesting that gargalesis is much less common amongst animals, and has only been well-documented in humans and a few primates. Recent work though has shown that rats can be tickled and even laugh an ultrasonic laugh (~50Hz) that can only be heard with special equipment. Apparently the rats go totally bananas, rolling around and playing, in fact actively begging to be tickled. Bearing that need for an ultrasonic listening device in mind, who knows what other animals are laughing, tickling each other, and developing complex relationships without our awareness. Certainly bonding is no unique thing to humans, so that would tend to fit the bonding theory of tickling’s origins.

After all of this exploration, I hope that this enlightens your view of what it means to be human and I haven’t ruined for you the simple pleasure of getting tickled. 🙂

Blakemore SJ, Walpert DM, Frith CD (1998). “Central cancellation of selfproduced
tickle sensation”. Nat. Neurosci. 7:635-40.

Panksepp J, Burgdorf J (2003). ““Laughing” rats and the evolutionary antecedents of human joy?“. Physiol. Behav. 79 (3): 533–47.

Selden ST (2004). “Tickle”. J. Am. Acad. Dermatol. 50 (1): 93–7.


Anatomy in the news: Obstetric Fistula

Okay, let me just start this one off with a disclaimer. This is probably a subject many people would find unpleasant, so if you’re eating lunch, maybe come back after you’ve finished. Nonetheless, it’s a significant health issue worth talking about and it’s all about anatomy, so I feel like I have something to say about it.

You may have recently seen or heard something in the news about a condition called Obstetric Fistula. It’s a complication usually seen in cases of prolonged or obstructed labor. What happens is the walls of the vagina (or birth canal if the “v word” is too much for you to handle) tear during delivery. The rectum and bladder, situated behind and in front of the vagina, respectively, can then also tear. Then when they heal, they heal together creating an artificial opening from the bladder to the vagina or from the rectum to the vagina. Check out the illustration of a midline cut pelvis for clarification, courtesy ADAM.

This is not a significant medical problem in the developed world where perinatal and obstetric medicine is sophisticated and freely available. However, in undeveloped countries, such as many in Africa, obstetric medical aid is often not available and when it is, there is usually a lack of basic tools that would allow the physician to do their job to the best of their ability. A recently released documentary called A Walk to Beautiful does a great job of telling the story of four women from Ethiopia who deal with this debilitating condition. I caught it on PBS, but it comes out on DVD soon. After their traumatic deliveries, which almost always result in stillborn infants, the women do not have the option to get surgical repair, so they are forced back into their communities with no bladder or fecal control at all. I’m not just talking leaking during coughing, like stress incontinence (which affects millions of women after childbirth, here and everywhere else in the world), I’m talking constant flow of urine with no regulation whatsoever, or even worse, the same scenario with feces. It’s not hard to imagine that these women are completely cast out of their societies. They are perceived as filthy and broken, often useless to even their husbands.

As I mentioned before, this is not a significant problem here in America and in other similar countries, because when this happens here, the physician immediately repairs the tears and the mother can heal in the hospital before returning to her normal life. In Africa, the supplies and staff it would take to perform the fistula repair are cost-prohibitive for many of the obstetric clinics, so the surgery is not even an option. And when I say cost-prohibitive, let me be totally clear, the total cost of the surgery is $300.00. Crazy world! Thankfully there are a growing number of “doctors without borders” who are bringing this surgery to the women of Ethiopia and other countries in Africa for no cost. Hopefully their compassion can relegate fistula to the fringes of medical concern in these places.

I could probably go on for days about the anatomy of the pelvis and how delivering a baby is a unique anatomical challenge for humans. Did you know that we are one of only two species of mammals that has difficulty delivering babies? This is because of two things. First, we walk on two legs. Walking on two legs requires a narrow pelvis, so the center of gravity can easily shift as we step from one leg to the other. If we had larger pelvises to make deliveries easier, we would tip over when we walked. Second, we have larger brains for our body size than any other mammal, which is probably not a surprise when you think about all of our abilities to process complicated thoughts and emotions into decision-making. Interestingly, we’ve already evolved to reduce brain development as much as possible until after birth to accommodate for our mothers’ smaller pelvic dimensions. Consider the relative brain development of a newborn baby and a newborn horse. The newborn horse is running around in a matter of hours, walking alongside its mother. The newborn baby can’t see colors or discriminate complicated sounds, has little motor control and most certainly can’t walk alongside mommy for many months. It’s funny that even that adaptation isn’t enough to counteract the narrow pelvis-large brain dilemma.

Incidentally, the other mammalian species that has difficult deliveries is the squirrel monkey. They are a dwarf species that gradually evolved smaller bodies but neonatal head sizes did not diminish similarly over time. Squirrel monkeys lose something like 30% of their babies in delivery, so obviously it’s a big problem for them. How significant is this problem for women? According the World Health Organization, over 500,000 women die each year in childbirth. And in Africa alone, as many as 3 million women a year are permanently handicapped by obstetric complications.

Some people have said that women have been having babies without obstetric help for thousands of years before doctors came along and ruined it with drugs and hectic deliveries. First of all, people have been helping women have babies for all of those years, only they weren’t called doctors, they were called midwives. And unfortunately due to rampant sexism in the middle ages, we have a rather spotty historical record of the science behind their amazing work until the physicians in the 17th century “medicalized” it. Second, those drugs and hectic deliveries have no doubt saved countless lives of mothers and their babies.

The home birth issue has been hotly debated in recent years. Do I think having a baby at home is irresponsible? Not if the attending midwife is aware of the facts and able to deal with a dangerous situation. If I had a uterus and it was my choice? I’d probably be at the hospital, although I tend to favor medical solutions over natural, homeopathic or faith-based ones in general, and I’m not a woman anyway, so I’m not sure what my opinion really means.

It’s an interesting thing, having babies. Me Mom and Santa ClausIt’s one of my favorite things to teach about in class. We’ve all been born and many of us will have babies of our own, so it’s immediately relevant and captivating to an audience. Everyone can imagine what their own mothers went through, and we should all thank them for taking on the challenge. There’s mine at right trying to make me not fear Santa Claus. I think we also owe a debt of thanks to the medical professionals who helped out our moms, and to the many others who continue to take on this uniquely human issue.

Don’t worry it’s just me

Hey there, thanks for coming to my brand new sparkly blog. I’ve been thinking about starting a blog in earnest for some time, but I’ve had trouble narrowing my focus onto a particular theme or avenue of my life. I never really did figure that out, but maybe a focus will reveal itself over time.

I call my webpage “theanatomist” because that is my job. I am an anatomy professor at a large medical school. I also think that I tend to see the world and my own life from the perspective of an anatomist. When I teach anatomy, one of the biggest messages I try to convey is the connectedness and relatedness of the body. Every muscle is somehow related to every bone, nerve, artery, etc. through an elegant system of attachments, both visible and invisible. This connectedness really matters in a clinical situation where one thing is injured leading several others to topple like dominoes. Similarly, there is remarkable connectedness between bodies. Once you get the skin and fat off, we’re all pretty much the same parts arranged in exactly the same way. I see everything in my life and the world as incontrovertibly linked. I remember the first time I had the realization that I am a part of everything else, and everything else is a part of me. I felt strangely safe.

When I think about why I decided to devote my career to the study of anatomy, it doesn’t take me long to come up with the reason. It’s simple – I want to be able to construct an entire human being by myself in my mind. From the cells to the tissues to the organs to the whole crazy functioning body, leaving no stone unturned. Of course this is probably impossible, but it leaves me with a place to go in a science that is in many ways no longer changing.

Outside of my professional life, I think most people who know me would describe me as funny, smart, easy-going and caring. I find myself to be predictable, unmotivated and a chronic quitter. I’ll concede to being funny, smart, easy-going and caring, but that’s not what I see right away. Funny how that works. The one person who probably sees all of these things is my partner Jason. He and I share our life together in Iowa City, the proud owners of an ever-growing pet family. In some ways we’re the so much the same (love of lifelong learning, need for quiet time away from the world), in others we are complete opposites (organization [me lots, him none], creativity [him lots, me none]). In other words, we suit each other perfectly.

I hope you enjoy this and hopefully many forthcoming blogettes. You can expect to read stories about my life in the academic world, good times with friends and family (sorry lolcats haters, but pets are included in that), and the adventures of two definitely hip but decidedly unfabulous gay guys in Iowa who just bought their first house together.

Peace,

D