T1 – 004: Three Cadaver
A while ago, behind the scenes, we discussed the possibility of starting a League podcast for people who want to listen to our site. This is sort of a first beta test. Text, of course, is available below and at the usual location, but here is also a recorded version of this post. Please indicate in the comments if you think it’d be a good idea to develop this idea further.
“I have an M.D. from Harvard, I am board certified in cardio-thoracic medicine and trauma surgery, I have been awarded citations from seven different medical boards in New England, and I am never, ever sick at sea. So I ask you; when someone goes into that chapel and they fall on their knees and they pray to God that their wife doesn’t miscarry or that their daughter doesn’t bleed to death or that their mother doesn’t suffer acute neural trauma from postoperative shock, who do you think they’re praying to? Now, go ahead and read your Bible, Dennis, and you go to your church, and, with any luck, you might win the annual raffle, but if you’re looking for God, he was in operating room number two on November 17, and he doesn’t like to be second guessed. You ask me if I have a God complex. Let me tell you something: I am God.” – Jed Hill, cardiothoracic surgeon from Malice
This post is the penultimate installment of a series on the dissection of a human cadavers. Previous posts in this series can be found here:
I recommend that the posts be read in order.
We detached the sternocleidomastoid and infrahyoid muscles from their sternal and clavicular insertions. Then, I took a manual bonesaw and cut through the clavicles at their midlengths. By this point, I had some experience with both manual and electric dissection tools, and I had developed a strong preference for the feedback, precision, and dexterity offered by manual bonesaws and bonecutters.
These manual tools also look more like props from the Saw series of horror films than their electronic analogs, which is a plus. I cut across the chest at the level of the xiphosternal line – about two inches below the nipple – being careful not to saw through any of the soft tissue deep to the rib cage. After making connecting cuts via the midaxillary line, we removed the thoracic wall and perceived the inside of our human cadaver for the first time…
The samurai warrior, Miyamoto Musashi, wrote the Book of Five Rings in 1645. This book is an instruction on the art of the sword and the martial arts; yet, it is applicable to other facets of life. Musashi is known primarily for being a single-combat duelist; yet, his meditations on each of the elements comprising the five rings – earth, water, fire, wind, void – are instructive even to the anatomy student. The Book of Five Rings is accordingly divided into five sections: one for each of the elements.
The Book of Earth concerns principally the foundational knowledge that all warriors must possess. It refers explicitly to the actual elements of strategy taught by Musashi. In the Book of Earth, Musashi wrote, “Know the smallest things and the biggest things, the shallowest things and the deepest things as if it were a straight road mapped out upon the ground.” In this book, Musashi discusses what weapons to use outside versus inside, meditates on the use of guns versus the use of the sword, and discusses the aspect of timing.
Whereas the Book of Earth deals with technique, the Book of Water deals with strategy. Water is flexible and dispassionate, and it seeks the most efficient path. As water does, so should the warrior be able to switch between methods and movements when in battle. In the Book of Water, Musashi says: “Adopt a stance with the head upright, neither hanging down, nor looking up, nor turned to the side.” Musashi stipulates that a warrior must be able to determine many things around him without moving his eyes, that being overly reliant upon some method of attack is worse than poor technique. Finally, Musashi advocates his flowing water cut for situations where the warrior is evenly matched and has fought to a stalemate. The prescribed movement is to strike “like stagnant water” – to cut as slowly as possible with one’s long sword. During this slow cut, both you and your opponent will be searching for an opening in each other’s defense. Your opponent will either push against your sword or attempt to disengage. This will allow you to perceive your opponent’s mind and to strike confidently and powerfully to defeat your opponent with movement that mimics the natural flow of water. Water is flexible and dispassionate, and it seeks the most efficient path.
The Book of Fire deals with vantage point and other essential preparations for specific battles. Unlike earth, which deals with foundational knowledge, and unlike water, which deals with the moment and follows particular rules, fire is situation-specific and unpredictable. In this book, Musashi discusses particularities of urban combat, the importance of securing proper ground, the art of distraction, timing, the element of surprise, and other spontaneous methods to win the battle before it has begun.
The Book of Wind concerns the importance of empathizing with the enemy. Not only must the warrior know all there is to know about his own school of swordsmanship, his own tactics, and his own mind, but he must understand his enemy better than the enemy understands himself.
Finally, the Book of Void concerns the understanding of that which does not exist. It is of utmost importance that the warrior be able to perceive that which is unknown and that which is unknowable. Avoid the tendency to favor your own thoughts and views. At the moment of judgment, empty your mind. Strike from the void.
Among the myriad syndromes of the thorax, perhaps the most surprising is the phenomenon of rib notching. The aorta is the main artery to the lower extremities, but it is not the only way blood can get there. Blood can also get to the lower body through anastomoses – the backroads to the aorta’s interstate highway. Indeed, when something is obstructing flow through the aorta, such as coarctation, a congenital heart defect, atherosclerotic plaques, or a tumor, blood flows through the intercostal arteries, causing them to increase markedly in diameter. This is most often picked up on x-ray, where it can be seen that the swollen intercostal arteries have eroded notches into the ribs – that is to say, blood has defeated bone, and it always will.
From age thirteen, Miyamoto Musashi is believed to have defeated more than sixty warriors in single-combat. His first duel was fought against Arima Kihei, who had come to Musashi’s village and posted a public challenge. The then teenage Musashi had written his name underneath the challenge. Musashi’s uncle begged Arima Kihei to forgive the insult, which Arima agreed to do as long as Musashi publicly apologized to him at the appointed time. Instead, Musashi charged with a spear, struck Arima between the eyes, stunning him, and then beat him to death in front of the village.
Musashi left his village at age sixteen and traveled the country engaging in duels. In the year 1600, he fought for the armies of the west against Tokugawa Ieyasu, whose descendants would go on to rule Japan until the Meiji emperor took power in the late nineteenth century. At the age of twenty one, Musashi fought duels with many of the elite warriors of the eight martial arts schools of Kyoto and did not lose. He annoyed and defeated many of these serious warriors with tactics such as arriving very late, hiding in bushes, and wielding two swords instead of one.
At age thirty, Musashi fought a duel against Sasaki Kojiro, known as the demon of the western provinces. The duel was to be fought on an island. Musashi arrived very late, which upset the supporters of Sasaki. Upon arrival, Musashi quickly killed his opponent with a wooden sword, which legend says he carved from the oar of the boat that brought him to the island, and then he quickly escaped. Two competing theories exist to account for Musashi’s unorthodox tactics in this duel: one is that Musashi timed his late arrival to take advantage of the sun in blinding his opponent; the second theory is that Musashi timed his arrival to take advantage of the tide for a quick escape when his opponent’s supporters inevitably cried foul and turned on him.
Musashi spent most of his later life as a journeyman, going through several masters and failing to achieve the kinds of appointment to which he aspired, including an appointment as adviser to the Tokugawa shogun whom he had fought against. Later in life, Musashi traveled, painted, and wrote extensively on strategy.
Miyamoto Musashi died at the age of sixty from thoracic cancer.
The thorax maintains the current that sustains life. There are no more potentially damaging injuries to the body than those injuries to the thorax. It is bound by the neck and the body walls superiorly and laterally and by the diaphragm inferiorly. The diaghragm is a muscle – the third most important in the body – the great bellows of the lungs. Indeed, our battle against nature is often a battle to defend the thorax.
According to the CDC, over 600,000 Americans die every year of heart disease. It is the number one cause of death. Usually, death is from ischemic heart disease, where clots build up in the coronary arteries that supply the heart muscle itself. Chronic heart failure occurs from lifetimes coping with the strain of pumping blood to body volumes that nature never intended.
Cancers are the second leading cause of death in the United States. Cancers kill another 600,000 Americans a year. Of the hundreds of different types of cancer, the deadliest by location are: lung cancer – attributable to nearly 30% of cancer deaths (down from ~40% a generation ago); colon cancer (~9% of cancer deaths); breast cancer (~7%); pancreatic cancer (~7%); prostate cancer (~5%); leukemia and lymphoma (~5% each); liver cancer (~4%); esophageal cancer (~3%); and ovarian cancer (~2%). Of these deaths from cancers, almost half – lung, breast, esophageal – are due to thoracic cancers.
The third leading cause of death in the United States is respiratory disease, including COPD, influenza, and pneumonia. These claim another 200,000 Americans annually. Stroke is the fourth leading cause of death, at 140,000 annually, and it is the leading cause of disability. It is difficult to separate stroke – or cerebrovascular disease – from cardiovascular disease, as strokes often occur due to clots originating in the heart, as the result of chronic, uncontrolled high blood pressure, or due to other central causes.
Accidents and suicide kill 160,000 Americans annually; and another 85,000 succumb to Alzheimer’s Disease. Diabetes is arguably a cardiovascular disease due to its tendency to agonize the formation of atherosclerotic plaques that ultimately cause strokes and heart attacks as well as its devastating effects on the peripheral circulation. Due primarily to these downstream effects, diabetes kills 75,000 Americans every year. Renal disease, often downstream from chronic, uncontrolled high blood pressure, kills another 50,000 Americans annually.
Altogether, direct effects on the thoracic organs account for more than half of all deaths in the United States. If indirect effects, such as those related to strokes and diabetes, are taken into account, this figure approaches 70%.
The United States spends about 15% of GDP on health care, the highest percentage of any country in the world. Among the 34 OECD nations, Switzerland spends the second most on health care, at 11%. Switzerland usually vies with Japan for longest-lived citizenry. The OECD average for health care spending as a percentage of GDP is 8%. Despite the United States spending nearly double the average OECD nation, we are 27th of 34 OECD nations in terms of life expectancy (79th percentile).
Before I matriculated at medical school, I completed a postbaccalaureate premedical course at Harvard University. This program is run through the division of continuing education. It is open-enrollment, loosely structured, and designed for working professionals who did not major in a biological science to complete the prerequisites for medical school or for science PhD programs. As part of my program, I took a course in developmental biology for which I regularly attended a graduate-level journal club.
One day the teaching fellow who conducted our journal club, a researcher at one of the combined Harvard/MIT genetics labs, was very excited about new research that showed it was possible to induce cellular remodeling in damaged hearts. “Do you know what this means!?” he asked us. “It means we can cure heart disease!”
The amazing thing about the statistics though is that they point to the essential paradox of the American health care system: that, despite our futuristic technologies and clever, expensive solutions to complex problems, the vast majority of deaths could be prevented just by regular exercise and proper nutrition and by not smoking. That’s not to say we can cheat death. Someday you will die, it just doesn’t have to be from heart or lung disease.
You best protect ya thorax.
Gross anatomy concerns, above all, the physical appearance and relationships between structures. Little to no physiology or function is discussed except where it concerns systemic phenomena, such as blood supply and nervous input. When we explored the thorax, we simply: cut out the heart and lungs; investigated the great vessels, the coronary arteries surrounding the heart itself, the heart’s four chambers, and the lobes of the lungs; found the vagus and phrenic nerves, the sympathetic trunk and splanchnic nerves; found the internal thoracic artery, the thoracic duct, and the esophagus; and explored the thorax’s walls and caverns, including the topography of the thoracic spine and diaphragmatic recesses, with our hands. A similar protocol was in place for the dissection of the abdominal cavity.
Apropos, you are a thirty-foot tube.
The outside of you may stretch five or six feet, although, your legs and arms are merely accessories to the central axial body plan. Your real body stretches only three or four feet. It is represented by the distance from your mouth to your anus. The sole function of your arms and legs is to obtain resources for this axial body. (And the sole function of your axial body is to metabolize energy for your arms and legs. This really points out the absurdity of life, doesn’t it?)
Inside the hollow cylinder that is you at your most basic, distance from mouth to anus increases tenfold. The vast majority of this distance is folded up in your abdominal cavity, comprising the soft part of your belly – the anterior two thirds of the space stretching from the bottom of the ribcage superiorly to the pubic symphysis inferiorly. The function of this elongation, the gastrointestinal (GI) tract, is to provide as much surface area as possible for the efficient absorption of nutrients from food.
From the top to the bottom, the compartments are mouth, throat. esophagus, stomach, small intestine, large intestine, rectum, anus. As mentioned, the overarching modus operandi of the digestive tract is to maximize surface area for chemical absorption. This goal is met in the intestines by fractal-like repetition of foldings on the intestinal wall, all the way down to the level of individual cell membranes. In the mouth, the goal of increasing surface area for chemical absorption is met principally through the act of chewing, which breaks food up mechanically into much smaller particles. That is to say, the mouth is the initial site of food processing in the body. The throat and esophagus serve mainly to connect the mouth to the stomach, although there is a significant immune component in both the throat and esophagus. (I’m not sure why nature didn’t just put our mouths in our abdomens, but it’s too late to go back now.) Since the stomach is the most acidic zone of the body, with a pH around 2, it’s probably best to have a barrier between it and the site of initial food intake. Accordingly, the stomach and esophagus are separated, as with many of the compartments of the GI tract, by a sphincter, analogous to flood doors on a submarine. Likewise, at the distal end, a sphincter separates the stomach from the duodenum, the first segment of the small intestine, which has a basic pH around 8. As food passes through the duodenum to the jejunum and ileum, the lion’s share of chemical digestion occurs: nutrients are broken down into basic components and absorbed into the capillaries of the hepatic portal system. These capillaries eventually converge on the liver, which serves as a clearinghouse for everything absorbed through digestion. Along with the pancreas, the liver also manufactures chemicals for secretion into the GI tract to aid digestion. After the food bolus passes through the small intestine, it enters the large intestine, where it is dehydrated and prepared for excretion.
It is important to note that the GI tract is not part of the human body, but it is its own separate environment outside the body. The GI tract is populated by an entire ecosystem of bacteria and other microbes, many of which are crucial to proper digestion; in fact, there are ten times as many microbial cells in the GI tract of the average human than there are human cells in the average human body. This ecosystem, called the microbiome, along with its Helm’s Deep, the appendix, is an important frontier for scientific investigation – so far we know the microbiome plays a significant role in development, particularly in the prenatal period, and it is crucial in modulating metabolism and the immune system, but that just about runs up against the limits of our knowledge.
In my house, we try to waste as little food as possible. This is for reasons financial, ethical, and culinary. In practice, this means we take leftovers that would normally go into the waste basket and use them to make soup stocks. Right now, indeed, there are eight boiled-down stocks in my refrigerator, stored in mason jars – one vegetable, one chicken, two turkey, two beef, one shrimp, and one salmon. These are usually boiled down with a mixture of whatever other leftover vegetables and sauces it was convenient for us to throw in.
For dinner tonight we had sirloin steak, spinach salad, jambalaya, and roasted carrots. The canola oil, salt, and pepper that we used to fry the steak went into the stock along with the remnants of the salad and jambalaya, the heads of the carrots that we cut off before roasting, some celery that probably would have gone bad anyways, and the leftover rind of a wedge of Pecorino Romano cheese. I will continue boiling this stock down over the next three or four hours, extracting as much flavor as I can from the milieu of organic molecules and gross matter. At the end of the boiling phase, I will borrow a technique from organic chemistry: I will filter the substance remaining in the pan using a colander and then wash it into the filtrate with a small amount of water. I will then boil down the filtrate until it has lost enough volume to fit inside a one-quart mason jar, which I will label with the contents and today’s date using masking tape and black sharpie. The remaining organic sediment – consisting of translucent carrot heads, chopped celery, beef fat and cartilage, crushed bones, herbs, apple cores, and other assorted scaffolding – is left in the colander and discarded in the waste basket at the end of the whole process.
This organic waste, in many ways resembling a fine chicken curry, is what the pelvis of a cadaver looks like after dissection: a big mess of bone, musculature, afferent and efferent nerves and vessels, and connective tissue – everything is brown and impossible to identify.
“Sit down, Dad.” I was told by the anesthesiologist. My wife’s belly was cut open on the other side of a curtain, and my newborn son was about to take his first breath. They knew I was a medical student, that I could “handle it”, but they still kept me on the other side of the curtain. Another medical student, a third-year, stood next to our OB/GYN doctor while she performed the procedure, occasionally answering her questions or handing her tools. He was the one who woke us up every morning at 5:00.
I’m what’s called a nontraditional medical student. I’m 30 years old, had a life and career well established before I even considered the possibility of going into medicine, and am married with four children. I met my wife in Japan, where I worked for five years. Our first child was born there. At that time, my wife was in the hospital for two weeks after going into labor. We couldn’t quite figure out why the baby wasn’t coming out. A lucky ultrasound later, we saw our daughter’s umbilical cord wrapped twice around her neck. An emergency c-section delivered her to us safe and healthy. She’s five now.
When I found out I got into medical school, we were already three months pregnant. At seven months, my wife had braved the trip down to New Orleans, through the stifling south. Negotiating the backwards insurance system here was (still is) a nightmare.
I have no doubt that obstetrics and gynecology is by far the most challenging specialty in all of medicine. Not only are you expected to be a doctor and a surgeon, not only is your ability to prepare and control your own schedule virtually nonexistent, not only are the stakes extremely high if you screw up, not only is your pay on the lower end as far as specialty pay goes, not only do you have to consider the needs of two separate patients at the same time, not only do you have one of the highest malpractice burdens of any specialty, not only do you have to deal with, arguably, the most challenging region of human anatomy, not only do you have to deal with medical students who have never seen a vagina, not only do you face institutional and cultural sexism and a male-centered medical education paradigm, not only do you have to answer for shocking standards of national prenatal health, but you also have to deal with patients who think having a baby is like planning a wedding.
There was a lot of small talk during the procedure: I asked the anesthesiologist how he enjoyed being an anesthesiologist (I seem to get along well with them). He loved it, he said, it’s great to be a participant in nearly all aspects of medicine and to get to treat both kids and adults. My wife commented afterwards, that after our son was born and I accompanied him to the various newborn procedures while they stitched her back up, our OB/GYN – who we love and who is definitely a zombie apocalypse first-round draft pick – heard her favorite pop song on the OR broadcast radio and began enthusiastically singing along. Since my wife’s voice could not be heard above the dance party, she had to make lots of strange facial gestures in order to signal that her pain-killers were wearing off. The anesthesiologist quickly came to her rescue.
Sure enough, our son was born and healthy: ten fingers, ten toes, seven pounds, ten ounces, no cyanosis, no omphalocele, no anencephaly, no tetralogy of Fallot.
“Shotgun penis!” my friend said. He wanted to be the one to do it.
It was now time for us to dissect the genitals of our cadaver. Approximately half the cadavers in our lab were female and the other half male. We had a male cadaver, so our genital dissection would be of the male genitalia. Groups on either side of us had female cadavers, so we were afforded the opportunity to explore the female genitalia as well through the dissections of other groups.
First, we inserted a finger into the scrotum through the inguinal ring, which had already been dissected. Then, we used scissors to make a vertical cut down the anterior surface of the scrotum, making sure to cut through the skin and underlying layers of fascia. Next, we used blunt dissection – meaning just our fingers with no tools – to tear the testes and spermatic cord from the scrotum. We cut the ligaments attaching the testes to the inside of the scrotum, but we preserved the spermatic cord coming down from the abdominal cavity. The spermatic cord contains the ductus deferens, within which semen travels to be ejaculated, along with the testicular arteries, veins, nerves, and lymphatic vessels, and the cremasteric muscle, which is under autonomic control and causes the testes to recede towards the abdomen. We explored the contents of the spermatic cord, using a probe to separate the various layers of fascia and to tease out the ductus deferens, the testicular arteries, veins, nerves, and lymphatic vessels, and the cremasteric muscle fibers. We noted their relationships with one another, the inguinal canal and the testes.
Next it was time to dissect the testes themselves. Within the scrotum, the testes are covered by several layers of fascia. We used our fingers to pinch these layers, and then cut them open with scissors to reveal the testicular parenchyma. After that, we used a probe to follow the ductus deferens to its origin in the epididymis, the convoluted network of tubules attached to the side of the testis that serves as a repository for mature sperm before they begin their migration to the urethra.
We used a scalpel to cut each testis in half from top to bottom and then used the epididymis as a guide to open each testis like a book, revealing the seminiferous tubules inside. We used forceps to tease out some of the sponge-like and intricate seminiferous tubules inside the testes. These resembled thick tufts of fine hair.
Next, it was time to skin the shaft of the penis. In the anatomical position – the position that is defined as the default for descriptive orientation – the penis is erect, which means the soft underbelly of the penis is considered the ventral side. To correctly orient ourselves for dissection of the penis, we held it aloft above the body. We started our dissection by making a careful incision around the base of the penis, where it meets the scrotum. The skin is very thin here, so we were careful not to accidentally cut any of the delicate structures below. We next made a midline incision from the base of the penis to the anus that split the scrotum and perineum. We detached the scrotum and placed it in a tissue container; then we reflected the flaps of skin laterally to afford a better view of the muscles underlying the base of the penis.
Next we used the scalpel to make a longitudinal cut along the ventral surface of the penis, from the scrotum to the glans (head). We cut another circle around the skin just proximal to the head. Then we peeled off the skin of the penis. We explored the shaft of the penis using our probe and fingers, identifying the superficial external pudendal artery and vein, the superficial dorsal artery and vein, Buck’s fascia, the suspensory ligament, the deep dorsal vein, the dorsal artery, dorsal nerve, and tunica albuginea.
After exploring the shaft of the penis, we inserted our probe into the urethra and used this as a guide to split the penis in half down the midline. From the tip of the penis we cut in the direction of the pubic symphysis, slowly splitting the shaft in half at the midline. Inside the shaft, we studied the glans, the urethra, the assorted blood vessels, and the openings of the ducts of the bulbourethral glands. We studied the erectile tissue within the corpus spongiosum of the penis that surrounded the spongy urethra along with the erectile tissue of the corpus cavernosum. Finally, we identified the deep artery of the penis – the blood vessel responsible for erection – and traced its origin to the internal pudendal artery.
Since all humans beings start out in the womb as morphologically asexual, with indifferent gonads, male and female genitalia have analogous structures. For instance, the scrotum is analogous to the labia majora; the penis is analogous to the clitoris, and the prostatic utricle is analogous to the uterus. While we did not have the opportunity to work directly on a female cadaver, we were able to take advantage of the work of other groups. Likewise, we were happy to teach other students about our cadaver’s male anatomy.
Gallows humor managed to creep into many of the procedures, as classmates ferociously wielded bonesaws or made references to House Bolton. A member of the group next to us cackled maniacally as he sawed into the vagina of his cadaver, through the cervix and uterus, up the middle of the spinal cord all the way to the fourth lumbar vertebra. Elsewhere, groups with hemisected genitals were studying the revealed structures: the uterus, fallopian tubes, and ovaries of female cadavers; the prostate gland of male cadavers; copious pouches of Douglas, bladders, rectums, and anal canals all around.
One of the things I noticed when I first came down to New Orleans was just how many homeless people seek shelter under Highway 10, which cuts through the middle of the city and runs right next to the medical district. In summer, at least, this is doubtlessly an attempt to escape the weather.
My drive to class each day takes me down Claiborne Avenue, alongside Highway 10. Everyday I ignore the homeless people. I do everything in my power to avoid eye contact at red lights. I do not read their signs. I give them nothing.
I’m sitting right now on my comfortable leather sofa, writing this on my laptop. My wife and youngest daughter are next to me. My youngest daughter just got out of the bathtub, and my wife is reading her a bedtime story while her two older sisters continue to play with the bubbles and our newborn baby sleeps soundly in the other room. I have headphones in, and I’m listening to classical music. I feel a deep sense of satisfaction with life. I know I have four years to go until I’m a doctor and after that I’ll have to go through internship, residency, fellowship, etc, before I can really practice. But after struggling for the last few years, I know I’ve finally made it. Granted, I’m paying a lot for my medical education; I won’t have money for a long time. Yet, the career trajectory for a doctor in our country is straightforward and safe; nine out of the ten highest-paying jobs we have are in the medical field; disease is recession-proof; and, especially with the baby boomers approaching their twilight years, I will not have to look far for work in the years to come.
Still, there is something not quite right.
I remember a discussion I had with my sister a few years ago about giving spare change to homeless people. I didn’t think it worked. I thought there were better approaches – structural changes, advocacy, volunteering – that could go a longer way. I wasn’t sure if hand-outs exacerbated the problem or not.
Here I was, stopped at a red light. “Hey, Massachusetts!” a voice called out. She must have noticed my license plate. I recognized the voice, or at least, I recognized the kind of voice it was: a voice strained by a lifetime’s worth of exposure to the elements, to heat and to cold, to pounding rain and burning sun, to hardships, to abuse, to the stresses of an uncertain tomorrow, to being ignored, “I’m from Brighton. I was born at St. Elizabeth’s…”
The light turned green. I drove off on my way to anatomy lab, to dauntlessly continue my intellectual quest. All day I couldn’t stop thinking: my cadaver, the homeless lady, the miserable and diseased and suffering people all around us – they were once someone’s baby.
Once, they came into the world and brought indescribable joy to someone.