It is the summer after my first year of medical school, and we have a bit of a break in our regular coursework. Almost all of the students do some sort of research or community health project over the summer. The diversity activity of what my colleagues do is really quite astounding and is one of the things that makes me feel particularly honored to be able to study with them. For those interested in international health or health policy/economics, it is an opportunity to do some field work abroad. Some of my classmates are in places as far flung as Kenya, Ecuador, Haiti, Lebanon, Pakistan, Bangladesh, India, and even the UK. Those are only the ones I can think of right now. The rest of the class is mostly doing research projects here at the medical school, ranging from pure basic science (pipette in hand) to population health research in the underserved communities in the area. It’s not entirely work all the time though, as most everyone does a little bit of travel and vacationing, whether it is a trip home or to a vacation spot for fun.
I’m one of the people doing research here at the medical school. Recently, I had family visiting for a week, so I spent most of the time driving around to see things like the Golden Gate Bridge, Alcatraz, giant Redwood trees, asian markets, and other tourist sites. Now it’s time to get back to work and also to get back to my electives.
One of the electives I am doing is an anatomy elective. To many people, the medical school anatomy class is something of a right of a passage and something of a major leap forward in training, differentiating it from everything which has come before. Our anatomy ran for two quarters. We had lectures from some amazing anatomists (in our case some great UK trained surgeons), but then an anatomy lab with cadaveric dissections. We had some great instructors for this as well, including a pathologist and professional anatomist along with some great teaching assistants who were more senior students. For the lab, four students were assigned to each cadaver and we started by working from the neck downward for the first quarter, and then did head and neck for the second quarter. At first, we were all very timid to even be in the anatomy lab with the cadavers in the open body bags, let alone begin the dissection. However, after spending several hours a week working with the cadaver, you become extremely used to the process and it becomes perfectly normal to be holding someone’s heart in your hand as you slowly dissect away all the fat surrounding the coronary arteries.
I can’t begin to explain how important to my education this process was. The human body is incredibly complex, and it is important to know how it is all put together. When doing a physical exam on a patient, it is very important to have a good ability to have a three dimensional concept of where things like the heart and lobes of the lung are situated. It’s not about being able to name all the different parts in some sort of rote memorization process, although knowing all the building blocks is an essential part of the foundation, what we are actually tested on is relationships, such as knowing what nerve carries sensation from which patch of skin, which nerves innervate which muscles, which organs in the abdomen are supplied by which blood vessels, and all the other important clinical relationships. It’s only by untangling all the complex inter-relationships that you can understand why a punctured eardrum could lead to a change in taste sensation or how an aortic arch aneurysm can cause hoarseness through the left recurrent pharyngeal. It was also a particularly moving experience. At the end of the full class, we had a memorial service to give thanks for those who had donated their bodies. Some of the medical students read poems they had written or otherwise expressed their feelings about the experience. Because of it’s importance, I have registered for whole body donation. I am registered as organ donor as well, which would take precedence, but in case I am unable to help give a gift a life, I can hopefully give a gift of education. If anyone reading this is interested, I can give a more thorough description of the anatomy class and my experiences with gross anatomy. Just post questions in the comments.
In addition to learning a lot in anatomy, I really enjoyed just the process of dissection and working with tissue. Each individual varies a bit (sometimes quite a bit) from the textbook, and it is something of a process of discovery and investigation to trace out all the structures such as paths of arteries, veins and nerves. I also enjoyed working with my hands and doing something manual as a good break from the many hours of sitting in class, studying, or working on a computer doing bioinformatics and on Tech Loris, so when the opportunity arose to do some anatomy electives I jumped at the chance.
The anatomy division offers a few different electives at a range of levels. Some are for non-medical students, including summer programs for high school students; courses for undergrads and grad students in the life sciences, art students, and bioengineering students; and additional electives for medical students. Many of these courses do not involve the students actually working with human tissue themselves, but are taught through the use of “prosections“. These are dissections done by a “pro”, designed to highlight a particular aspect of anatomy, such as a confusing relationship or something of clinical significance. I signed up for a med student elective working on making prosections. That’s how I ended up with a head in box.
For my major project as part of the elective I wanted to a dissection of the side of the head and face, going in through the cheek bone to the base of the brain to show the path of the trigeminal nerve. The trigeminal nerve is the fifth cranial nerve (CN V). As the name suggests, it has three parts. Actually, I was a little confused about the meaning of the name. My limited Latin suggested it meant “three twins”, which is actually correct, and I thought that it meant “triplets”, but that’s not quite the case. It refers to the fact that there is a trigeminal nerve on both the left and the right, so it is really like three sets of twins, one for each branch on either side. The trigeminal nerve comes out of the brain stem and branches out to go provide many nervous functions of the head/face. It is responsible for touch sensation for the whole face, the muscles of chewing, some taste sensation, as well as some of the muscles of the ear, throat and neck. The branches of the nerve travel through several bony canals throughout the front of the skull.
The name of the nerve is also included in the name of the serious disorder, trigeminal neuralgia. This is the famous “suicide disease”. It is associated with such serious, unremitting pain that sometimes those who suffer trigeminal neuralgia have been known to be driven to suicide.
In order to do a dissection elucidating the path of this nerve, I needed to have a cadaveric specimen to work on. After working a bit on some other areas of anatomy, including a female pelvis, our anatomy instructors provided me with a head to work on. It was the formalin fixed head of an older gentleman, and it was in a plastic box. It was in the sort of giant plastic tupperware-type containers that you might use to store old holiday ornaments in the back of the closet. It had a yellow sticky on the front which said “Alex’s head”.
On the first day I began working by dissecting the skin of the side of the face, documenting the process with an SLR with a macro lens. Over the course of several weeks, working for a few hours each Tuesday afternoon, I removed the cheek bone (zygomatic arch), removed all the muscles which close the jaw (including the temporalis), opened up the side of the skull, removed part of the anterior portion of the temporal lobe to view the skull base and the anterior brain stem, and even dissected out part of the Circle of Willis. All this work involves a mix of brute force hard work, cutting with a special oscillating electric Stryker saw or grinding with a Dremel to get through the bone, all the while being incredibly careful and picky to not damage any tissue, combined with very delicate, deliberate dissection with tiny scissors or a lancet. After all this work, I tried to dissect out the trigeminal nerve from the meninges (the tough covering of the brain). To put this in context, it’s a bit like trying to do demolition of a cinderblock house without damaging all the precious murals painted on the walls inside. I’m not too happy with how it worked out, and I know I can do a better job, so now I am going to start in on the other side and try to do a cleaner, better job of the dissection of the contralateral trigeminal nerve.
I have to get back to working on my head in a box. Wish me luck.