On the first day of orientation to gross anatomy six weeks ago, we were told that people looked just as different on the inside as they do on the outside. The last two weeks have proven that statement, as we dived into the abdominal cavity, revealing all the organs below the diapraghm.
First let me say that there is a ton of stuff packed into this space, and the individual organs are not in their own separate little compartments: they are all squished together, for reasons not only of space constraint, but also due to the embryological origins of the organs, and the blood vessels and nerves they are required to share. We first study these animated pictures in our book, where the stomach is one color, the pancreas another, and the different sections of the intestines are clearly delineated. We learn in lecture what blood vessels feed which organs, and what kind of path the vessels take on their journeys to the organs: short, long, or arduous. We try to understand the very complicated nerve webs that are spread out all over the organs and the blood vessels. (Very different from the arm where a nerve goes directly to a muscle and doesn’t split into a large spider web of branches).
After lecture we prepare for the lab, change into our scrubs, and think about what the lab director told us the surgeons call the abdominal cavity: “The Temple of the Unknown.” How can that be, the professor just neatly explained the organs and the relationships they have to one another, the blood vessels and the nerves. It can’t be unknown. Ha Ha Ha…. From the very first cut past the abdominal muscles in our cadaver Larry, we are flummoxed because we cannot find the very first structure, which is supposed to lay over the small intestines, and according to all the pictures, is impossible to miss; it’s a sheet of connective tissue called the greater omentum, a result of the complicated folding of internal tissues when the fetus is growing. We are convinced we don’t have one, or think maybe it just got absorbed into the tissues of the small intestines.
After much digging around, (I’m convinced it has to be there), we finally find this greater omentum shoved way up near the diaphragm, hiding on top of the stomach. That’s NOT where it’s supposed to be. Then there’s the issue of the cecum, a part of the large intestine that’s supposed to sit way down by your pelvis, but on Larry is actually facing upwards, and sits in the middle of his abdomen. It’s as if Larry was hung by his toes, and all his organs did not have the benefit of gravity keeping them in their “place.” It doesn’t stop there. Later we find an extra artery for the testis that doesn’t belong. We determine it’s not a vein or a nerve by following it from it’s beginning to the end. Yup, it definitely goes through the spermatic cord along with the testicular artery, and it definitely comes off the right renal artery. Lucky Larry, he has double blood supply to his left testicle I say to the professor in the lab. Maybe not, he replies, more chances of loosing blood supply to the testis if it twists and turns inside the scrotal sac. Well at least it’s not a fatal variation, as those tend to stop the growing fetus from even being born.
I move around the classroom and see that we are not the only ones struggling with finding all the objectives – digging and digging through an insane amount of connective tissue, layers over all the organs, layers in between the organs, and some more layers just for the heck of it. Variations abound, both natural and unnatural. The natural variations include extra arteries or veins, or the artery or vein coming off of the “wrong” spot. The organs are generally in the same area, but sometimes, as with Larry, there is variation there too. Of course it makes sense. There is lots of room for movement in there, and if there wasn’t, a woman couldn’t accommodate the growing baby inside her uterus (which of course hogs the whole abdominal cavity by the end of pregnancy). Not to mention when my stomach expands grotesquely after a great meal at my favorite restaurant after stuffing myself. (It would have to be an Italian restaurant – I have no self control when oi comes to pasta and red wine).
There are also unnatural variations that indicate disease processes. Several of the women have had hysterectomies, but thankfully there is one gorgeous uterus that I was able to palpate and hold so delicately (Life grows in this little muscular sac!). The cadaver next to us has a HUGE heart, about four times the size of Larry’s heart, as their man died of congestive heart failure. Larry has a huge green gall bladder (hey, this is one part of the cadaver that does match the pictures in the book! But they probably won’t tag that on the exam – too easy….). Other gall bladders are small, blending in the with the grayish tone of the other abdominal tissues. Larry has a large hard bladder, the result maybe of a prostrate condition, while others are small pliable sacs. A male cadaver in the room has an enlarged prostrate gland. I could go on and on, but the point is that variations are the norm, and that we can look at them as a source of wonder or a source of frustration (or both).
It’s too early to tell but I am pretty sure that I don’t want to be a general surgeon. If it takes me two hours to find an artery underneath the small intestines, how long would it take me to find something on a live patient, when all the tissues are red and bleeding? They did show us a few pictures in class of gall bladder operations, and as the surgeon is showing us the picture of a tied off cystic artery, vein, and duct, all I see is blood! That’s what excites and challenges surgeons I guess. They have the knowledge base to understand the common expectations of location of the abdominal organs as well as their blood supply, along with the understanding that variations abound and must be looked for, in order to avoid snipping the wrong thing.
I look forward to the exam this afternoon. So I can put the abdomen behind me, and move on the the next set of objectives, to learn the anatomy of the legs and buttocks. Now doesn’t that sound like more fun? Cheers!