It’s Not Brain Surgery

Southside without students is like Camden Town without bohemians – quiet, and empty. For the first two weeks of my semester, the city around campus was pretty much derelict, save for the occasional vet student. Don’t get me wrong, it’s not that I’m a raging socialite, but their absence meant the people-watching from my kitchen was pants for the entire fortnight.

Where was everybody?

At home. Still on Christmas break. By the time they all began trickling in for the start of their semester, the vet meds had sat an exam, finished the entire renal module, and begun the endocrinology module. Vet school waits for nobody.

I’m pretty sure the last time I wrote was just before my December exams. Apologies for the radio silence, I’m sure you’ll forgive me once I’ve regaled you with everything that has occurred since!

So how did exams go? To put it briefly: professional exams are very, very hard – as many of you will know. Every time I’ve approached a vet school exam diet, it was with the feeling that the weight of all the information might just make me implode. In trying to offer context to these exams, I risk it sounding like enormous dramatisation or exaggeration. In a way, you might just have to take my word for how enormous an undertaking it all is. But if it helps to put it into perspective, I had seven days to memorise 99 hours of material for just three exams. Yes, I counted. Of course I counted.

The detail and volume of information a lecturer can cover in each hour is significant. In those 99 hours, we had covered locomotive anatomy, the digestive system, metabolism, the cardiovascular system, and the respiratory system; of dogs, cats, horses, ruminants, rabbits, rodents, birds, reptiles, amphibians, and fish. I consider the size of my head to be relatively average. And so when lectures finally ceased, I looked at the measly seven days of revision week and wondered how the hell I was going to get it all to fit into my brain.

Whereas I often hear my non-vet flatmates saying “I have an exam in a few days, I should probably revise”, my colleagues and I begin exam revision a minimum of 4 weeks in advance. But for three of those weeks, new material is still being taught and adding to the revision pile, leaving just seven days in which to face all of it at once.

The exams were one a day for three days. The short-answer paper on Tuesday, interpretation and multiple choice on Wednesday, and the ‘spot’ on Thursday. The format is just as it was in first year, so check out my post about AB1 exams here if you’d like to know what it all entails. On the one hand it’s like ripping off a plaster; over in a jiffy. On the other hand, it’s like riding Victoria Falls in a rubber ring. Once the precipice of Monday night arrives, you just have to hold your breath and hang on until it’s over.

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I took my exams at the Geography building on Drummond Street

It took the board of examiners far too long to release the results, but I’m really chuffed to say that not only did I float away from that particular fall unscathed, but did so in style. Across the three exams, my overall performance was 87%. Believe me, I’m more surprised than all a’ ya’ll!

This semester began all the way back on the 4th January, when the days were still so short that we’d wake in the dark and ride the bus home in the dark. By the end of week 2, we had covered all the lectures in the renal module, and by the end of week 3, the entire endocrine module too. Studying for an Animal Life & Food Safety exam during the first two weeks of 2017 set me behind in writing up the lectures, and even halfway into February I still haven’t managed the clear the backlog. Unbelievable.

Renal is a tricky body system, full of unfamiliar terms and layer upon layer of ion movements in all directions, checking and balancing against each other under the control of hormones from numerous other body systems. The result? I spent the first few weeks alternating between taking pride in my knowledge of how the kidney balances sodium, only to realise that I had confused it with the balance of calcium. Or potassium… or urea, or water, or bicarbonate…

How is it that my own kidneys can tick away and get on with all of these processes, and not let my cerebral cortex in on the secrets about how it’s all done?

No sooner had renal and endocrine finished, neurology began. As we waited for the very first lecture of this module to begin, our lecturer walked in. I did a double-take, this woman was impossibly tall. And when she opened her mouth, it took me a good ten minutes to start understanding what she was saying, between the deep voice and the slightly overdone BBC accent.

But tuning in to her accent did little to help me, because the words that came out sounded like a bizarre alien language that I couldn’t decipher. I eventually recognised that every other word in her sentences was either Greek or Latin, or both. All new body systems come with a whole new lingo, but a lot of them are familiar to the layperson, or are a modified version of Greek and Latin medical terms I already know. But the first neurology lectures flew right over the top of my head. I couldn’t keep up with the terminology, and without speaking the basic language, I couldn’t understand the content.

Very many of my evenings were spent labeling diagrams with terms like falx cerebri, tegmentum, diencephalon, pia mater, and cerebellar vermis, in the hope that they might stick in my memory. It didn’t feel like it back then, but those terms are now starting to roll off the tongue – that can only be a good thing. The problem with the brain is that it’s pretty amorphous and not fully understood. It’s comparatively easy to find and name structures in a leg or lung, but the brain is an alien organ with indistinct regions and a pretty non-intuitive layout.

But it’s an absolutely astonishing organ that’s part of the most sophisticated body system on earth. There’s also so much variety among the nervous systems of different species, and none are so different as man. The thing that makes humans so successful is also one of our most profound weaknesses.

*Nerd alert* Perhaps my favourite example of this is the difference in motor systems in humans compared to most other animals. The motor system can be broadly divided into a “pyramidal” and an “extrapyramidal” systems. The pyramidal system uses the higher centres in the forebrain (cerebral cortex) to send out two bundles of nerves (the pyramids) into the spinal cord to control movement. The extrapyramidal system uses scattered motor centres around the forebrain and brainstem to send signals into the spinal cord. That probably didn’t make much sense. But bottom line is this: man depends mostly on the pyramidal system, which is the better of the two for fine motor control. This system connects distinct regions of the brain to distinct areas of the body. So if you get damage to the region that controls the arm, you’ll get arm paralysis on the opposite side. This is the basis of a cerebrovascular accident (a stroke).

But the majority of animals use the extrapyramidal system predominantly. They don’t have fine movement, but their central motor systems are more robust. The extrapyramidal system gathers information from all over the forebrain and brainstem to control the body. So if you damage a specific region of the cortex in an animal, motor neurons from other regions can compensate. As a result, a brain lesion that would cause severe paralysis in a human may only present mild problems in a dog, or be completely unnoticeable in a horse. How cool is that?

Cool as it is, neurology is exceedingly difficult, so much so that some students in the past have used selective learning to pass their exams without studying the neurology module at all. The exam board were pretty quick to change the exam format so that you can’t do this any more, though.

My first neurology practical saw me sitting at a dissection table with a colleague. In front of me sat a brain, and an eyeball. The eyeball watched me from the tabletop as I listened to the briefing. Once the briefing was over, I had a better look at my brain. It was a herbivore, most probably a sheep, because I could see that the rostral colliculus on the tectum of midbrain was far larger than its caudal counterpart. In carnivores, the opposite is true. After making this observation I sat and considered how many times I’ll ever have to identify a disembodied brain in my veterinary career. Probably never.

I spent rather a long time just squeezing and poking at bits of the brain. It’s such a strange texture. It’s a bit like clay, and a bit like cheddar, and also a bit like rubber but more prone to crumbling. The whole thing was a peachy yellow-orange colour, and astonishingly fine blue blood vessels sprawled across its surface.

After identifying the external features, we found the landmarks we would need to cut it into slices at the right levels. Once this task was complete, we were left with a lineup of roughly circular slices through it that progressed from front to back – like an MRI but in the flesh. Slices examined and structures named, I moved on to a demonstration being given by a member of staff.

The teacher in question instructed everyone to go and get their eyeballs, and so I scurried off and returned with mine in my hand, and another two in my head. She seemed a bit nervous under the pressure of her student audience, and talked very fast.  Her eyeball still had its eyelids attached, and once she’d talked about them for a bit, she began tearing them off with her bare hands. To my surprise, the eyeball peeled like an orange. Next she talked about the extra-ocular muscles, and proceeded to cut them off with scissors. She was down to hard white sclera of the ball itself. After describing the structures from the outside, she said she was going to cut it in half. But her hands were shaking and the eyeball was slippery. Every time she tried to push the scalpel through the hard outer shell, it skidded out from under her fingers and rolled off across the table. This exact series of events was repeated over and over, like someone chasing a gravy-coated brussel sprout around their dinner plate. I was stood right at her shoulder, and was doing everything I could to keep a straight face as she tried to restrain the excitable eyeball.

In the end the eyeball was fully dissected, and I returned to my table to have a go myself. Having watched how it should not be done, I pretty deftly dismantled the eye. And what a weird thing it was. The vitreous humour wobbled out onto the desk like a weird blob of jelly, to reveal the beautiful tapetum lucidum that lines the back of the eyes in most non-human species. It’s iridescent turquoise like an exotic fish, and serves to reflect light back through the photoreceptors of the retina to provide excellent night vision. The lens was unexpectedly hard like a plastic pebble, which, much to my amusement, was incredibly bouncy.

Right at the end of this practical I went to check all of the prosected specimens at the front of the room, to review the structures in well-dissected examples. In the very far corner sat two brains that looked unlike any of the others. I went over to investigate and saw the tag, which read “human”. I scooped one up into my hands and examined the layout, naming the structures in my head as I went. And then for about a minute, I stood and contemplated that a person had lived inside this brain. There were memories in here, a whole lifetime of loving, laughing and learning. Who was it? Where did they come from, what kind of person were they? This is what remained of them, their entire perception of their world all inside this silent, pale organ, sitting in my hands. It was a strangely intimate moment.

Also a bit weird, put it down and move on.

A few days later I had a tutorial on brain imaging using MRI. We sat around in groups poring over grainy black and grey scans of dog brains. Neuroanatomy is hard enough when there’s real specimens and colourful diagrams, but requires some really careful three dimensional thinking when it’s presented as scans.

As we moved caudally, through the basal nuclei, the thalamus, back through the midbrain, pons, and cerebellum, we were getting quicker and more accurate in our identifications. And then we arrived at this:

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I just sat and stared at it.

No matter how hard I tried to find neurological structures, I just couldn’t see past the glaring knob and bollocks. Was this some kind of joke? If it was, the lecturer gave nothing away with her unsmiling expression. I had better keep it together.

Veterinary medicine is all about bumholes and genitals, and so I wasn’t remotely surprised when a few days later I found myself peering into the arse of a tortoise. It was my exotics revision session, the last chance to handle and talk about the reptiles, birds and exotic mammals before my practical exams. I had the funny little guy in the ‘hamburger hold’, where you grasp your tortoise as if you’re about to eat him like a burger. I was squinting up his clacker whilst the technician leading the session talked about how to sex them. I had spotted the spurs on each thigh that identified the species I had, and was probably a little close. Because as I was staring, his vent opened up and large ball of faeces began sliding out towards my face. I extended my arms as fast as I could to let the turd drop onto the table. And I’m telling you it’s a good job I did, because he wasn’t finished.

Like a bird, reptiles excrete brown faeces with a white urinary component at the same time. The second his mother lode hit the deck, he followed up with a spectacular jet of white fluid that almost reached the length of my arms and fell narrowly short of my clean white coat. I dread to think what would have happened if my face had still been staring down the barrel.

And so you could say my January finished with a bang. The lectures have been coming thick and fast, with no respite and hardly time to sleep! The backlog of lectures I accrued over the first week while studying for the Animal Life exam meant that during endocrine, I was behind in writing up renal. Then as I got on top of renal, I then had a backlog of endocrine lectures. I did get on top of those, but by that time neuro lectures were piling up. Currently, I have a few neuro lectures outstanding, and an increasing pile of reproduction lectures building up by the day. Its astonishing the pace that we move at, and this is why I haven’t written for weeks!

As irregular as my posts can be, please do watch out for the next post, because February has already produced some great moments to share. See you later!

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It’s frosty out at the Bush!

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