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Warning: This is another graphic dissection-related post and possibly contains some of the grossest descriptions yet. I also might ruin oranges, cottage cheese and s’mores for you forever. Read at your own risk.

Do you know what you get when you send out an email asking medical students if they would like to give up an afternoon to assist with an optional brain removal dissection? A lab full of medical students wielding bone saws and chisels.

Where do we cut? The top part, right?

(If you’re already rethinking your commitment to reading this post, the back button should be at the upper lefthand corner of your screen.)

We’ve started our unit on the central nervous system, which means I am in full neuro-nerd mode. (Another student called me that earlier today and I like the alliteration so well I decided to keep it.) We’re not actually doing a lot of cutting in our dissections for this unit, but the brains did need to be retrieved from their usual location. The idea was to use all of the brains from our cadavers along with a few supplemental brains* from surgical pathology so that we won’t have to alternate dissection groups like we have been doing with our cadavers.

Here is how to remove a brain:

First you have to remove the skin of the cranium. You do this by making an incision from between the eyes to the back of the head and from one ear to the other and then peeling back the flaps. This was a bit more intimate than I was expecting, given that we had covered the face of our cadaver on the first day of lab and had not uncovered it since. The rest of his body was devoid of skin except for the soles of his feet and the backs of his hands. In many ways our cadaver had ceased to feel like something that had once been a person. Uncovering his face and making that first incision between his eyes was different. I have a hard time attaching an emotion to it–I didn’t find it sad or gross or creepy–but I noticed it.

Peeling the skin off the bone of the scalp is like peeling an orange. It comes away with a good solid tug and makes that same soft unsticking sound The deep fascia underneath even looks like the white inner rind. Underneath, the top of the skull looks just like every skull you’ve ever seen, off-white and smooth. The temporalis muscle on each side (the thing that tightens up at your temple when you clench your teeth) is the only non-boney landmark. We reflected them back as well so that we would only be sawing through bone.

The striker saws have small, semi-circular blades. They cut through the bone pretty easily, but they are just unwieldy enough that it’s hard to judge how deep you’re going. The goal is not to saw through the entire bone, but rather a few millimeters deep and then to crack the rest of the way through with a chisel and hammer. Halfway through this process you have to flip your cadaver over to make a complete circle around the head. Then you flip it onto its back and saw across the top like a headband.

The bone saws kick up a lot of bone dust and the friction creates a bit of smoke. It smelled to me like burning marshmallows. (No, I wasn’t hungry during this dissection, I swear! I reasoned it out with another student later: marshmallows and bones are both made of gelatin, after all.)

Some of the cadaver brains weren’t properly embalmed, which brought a whole new meaning to the phrase “my brain is mush.” They were the consistency of cottage cheese and oozed out of the new opening in the skull. Even the anatomy professor was grossed out. Those brains were left in their respective cadavers with several layers of wrapping around them both.

Our brain was well-preserved. The skull cap made a ripping/popping noise as it came free: the sound of the dura mater (the tough, protective coating of the brain) pulling free of the bone. Then we sawed through the occipital bone at the back of the head so that the spinal cord could be severed.

Even then, there was a lot more to be disconnected: the roots of the dura mater, the vessels that carry blood into the brain, all of the cranial nerves (there are twelve pairs.) Then we were done, and the brain came free like it was never all that attached in the first place. What, all that work just for me?

Strange to think that the object I was cradling carefully in two hands (not-dropping a brain on the first day was pretty high on my to-do list) had held all of the thoughts, the memories, most of the personality of the person it once belonged to. It is dead now, fixed and quiet, but I wonder if someday we might be able to look at all of the connections that existed and see something of the thoughts that passed through it once. Or maybe we’ll discover that to be something completely unknowable, something greater than the sum of its parts. It sort of hurts my own brain to contemplate. In a good way.

Ze Brain

*Every time I say the phrase “supplemental brain” I want to make a joke about borrowing one for the next exam. I know, it’s terrible, but I just can’t resist.

It’s probably not the sort of thing one says in polite company, but I really like doing dissections in biology lab. It brings out the little kid in me, that part that loves to take things apart and see how they work, that finds the squishy insides of the animal to be both totally gross and totally fascinating at the same time.

The first dissection I did was in high school freshman biology. We studied frog anatomy, and the day before the dissection we were charged with observing “external characteristics.” This basically meant that right before we sliced into our specimens, we were given an entire lab period to bond with our frogs. One of my friends couldn’t take it and spirited her frog away by stashing it in the front pocket of her backpack. We released him into the creek behind the school; I have no idea if the environment there was at all suitable.

I expected to have a real problem with the actual dissection. It just didn’t seem like something I should enjoy. The frogs had their brains (literally) scrambled beforehand, meaning that their hearts were still beating when we opened them up. My group was made up of two other girls, both very tentative about the whole process, so I ended up taking charge somewhat against my will. I remember cutting my frog open very carefully and watching his heart beat inside of his spread rib cage. I was amazed. I knew that hearts beat, but I had never envisioned how violent it was; this ball of muscle twisting and writhing just behind a few layers of muscle and bone.

Since then I’ve always claimed to love dissections, and couldn’t wait to start cutting. We worked our way up slowly; first an earthworm, then a crayfish and an enormous cricket, then a squid and a clam. Of course the day we started on the fetal pig, which I had been looking forward to since we first went over the syllabus, I was in the midst of my aforementioned plague and spent most of the lab feeling nauseous from the stench of formaldehyde and trying not to cough on our specimen. It probably didn’t help that we were looking at the digestive system, which, even in a fetal pig, involves a lot of organs filled with fluids you would rather not contemplate too closely.

This week we tackled the circulatory and respiratory systems. Having moved out of the gunkier areas of the body and feeling more energetic, I recalled why I loved dissections so much. The heart lay in the center of the pig’s chest, shiny and strong; not beating in this case, but impressive nonetheless. The lungs weren’t fully formed, but it was easy to  see each individual lobe as it curled almost protectively around the heart. Ironically one of the things that gave me the biggest thrill was pulling back the connective tissue around the trachea and larynx; I was stupidly suprised to find that they looked just like the pictures.

Looking inside a living organism, particularly one as similar to humans as a fetal pig, feels special to me. I always imagine that pictures and diagrams are simplistic; a rough estimate representing a non-existent every-man. It surprises me to realize that it all actually looks like that when you get inside. The liver really is smooth and rounded, the aorta really does loop up over the top of the heart, the trachea really does look like rings stacked on top of one another. It’s a cliche, but inside we really aren’t so different after all.

We have one more biology lab before we’re done (I think a sheep’s brain might be involved). I’m not going to miss it exactly, but I will say that I’m not dreading cadaver lab in med school one bit.

I have a new ultimate challenge.

Last semester it was physics. For every hour of study I devoted to biology or organic chemistry, I gave three to physics problems. Every upcoming exam filled me with fear, every passing grade felt like a dodged bullet. When my final grade came in, higher than my wildest expectations, I was giddy with relief. The battle felt epic; the victory was sweet.

Now, though, physics is a known quantity. Sure, the material is new and just as mystifying as it was before, but I’ve become accustomed to the sense of bewilderment that colors most lecture classes. Having survived the final exam last semester, the smaller midterms seem less intimidating and my panic less acute.

Obviously it was time for a new challenge. And so it has appeared in the form of organic lab.

Like physics, organic chemistry lab is considered one of the pre-med weed-out classes. It is notorious for class averages in the 50s, with an epic final exam and lab reports a minimum of thirteen pages single spaced. When the undergraduates talk about the class there is a hint of fear in their voices.

We postbacs, however, get special treatment. Our organic professor is part of the program; he knows us all by name and teaches us separately from the undergraduates. We have no final exam and our lab reports are recommended to be about three pages long. When we pass by the undergraduate lab we see dozens of students frowning over their equipment in utter silence, while our TAs play music and have promised to get a beer with us after class sometime.

Which is the irony of this class being my new source of stress; there is really nothing stressful about it. Everything that makes the class a brutal, terrifying obstacle course for undergraduates has been removed. Friday afternoons should be fun; I already like organic chemistry on paper, it should be great to watch those principles enacted right before my eyes. Potions class, like in Harry Potter, one student called it. And it would be exactly that if it weren’t for the fact that I am completely terrible at doing actual organic chemistry.

We’ve had four labs so far and not a single one has gone off without problems. In the first lab my lab partner and I washed our equipment before we used it and the residual water interfered with our results. In the second, our substances refused to dissolve no matter how much solvent we added. The third gave us great results that we were later told absolutely could not, under any circumstances, be accurate. Our most recent lab yielded  no results at all, aside from a strange reddish sludge that our TA proclaimed, “Very interesting,” in a tone of voice suggesting he instead meant, “How the hell did you mess this one up?”

I’ve come to dread Fridays. No matter how much preparation I do ahead of time, nor how well I think I understand the concepts, the minute I step into the lab I feel I have surrendered all control. The magical organic lab fairies will decide whether or not I end up with a product, and apparently they’ve taken a dislike to me. The TAs and the professor assure me this is normal and how organic chemistry often goes. If that’s the case it’s a wonder more organic chemists haven’t blown up their own labs in frustration.

Don’t worry, I’m not planning on blowing anything up. With my lab luck it wouldn’t work anyway and I’d probably singe my eyebrows off in the process. But I remain disappointed to find that, while theoretical organic chemistry is one of my favorite science subjects, o-chem PhD is not in the cards if my MD falls through.

When was it decided that good scientists were fast scientists? Physics class seems to prioritize speed over accuracy in every way. In lab, the experiments are simple but numerous enough to fill the whole period even if you don’t take time to ask questions or measure things out accurately. The post-lab quiz, despite being online, is timed; 45 minutes from the minute you click the link, even if you click the link by accident. Exams for biology and organic chem. are given a separate period so we’ll have enough time to finish all the problems; physics is a race against the clock in the hour and fifteen minute class period.

It’s not that learning to work with a time limit is necessarily a bad thing, if for no other reason than the MCAT looming over our heads. But it’s frustrating to realize that a large part of my grade in the subject I find the most challenging won’t necessarily reflect my understanding.

Today our lab featured a motion detector and a long series of graphs that compared position, velocity and acceleration. The subject matter was simple enough; the concepts were ones we’d explored in the first week of classes. The real challenge was walking at the motion detector in a way that created the graphs we desired. As it turns out, walking at a constant velocity is nearly impossible. We spent most of the lab period trying to do it as effectively as possible.

Outside of the physics lab room there is a wide screen television mounted on the wall. It plays an ongoing slide show about the wonders of a physics major. Did you know it only takes these five classes to complete the major? And that physics majors are great candidates for medical school? I feel like they might have more luck if they spent a bit more time stressing the application of physics, and a bit less grading me on how smoothly I can walk toward a table.

Alternate Title: Things TV Didn’t Warn Me About Conducting Experiments (In honor of getting our final grades for the first semester of Chemistry Lab.)

  1. Safety goggles fog up. All. The. Time. I think I’ve done half of my experiments with impaired vision.
  2. Once heated up, test tubes, crucibles, and Bunsen burners take forever to cool down. And because the universe is cruel, they take longer to cool down when you’re running behind schedule and having nothing to do but watch the rest of the class leave you behind.
  3. Test tubes are really fragile. So far I’ve broken three of them; none of which were actually being used in experiments at the time.
  4. Most of a chemistry experiment is the math you do afterward.
  5. A drop of liquid makes a difference on your experimental outcome. So does the oil on your fingers and whatever residue is left behind by tap water.
  6. And yet “cleaning”  lab equipment involves rinsing it with tap water and distilled water; no soap, sponges or scrubbers to be seen.
  7. Every so often, after all of the waiting and the math and the possibility for human error, you get it right and watch your solution transform from deep indigo to completely clear in what looks like a reverse puff of smoke. Way cool.