Out On A Limb

Week four of Vet School saw an abrupt and merciful end to the onslaught of cell biology material. Although I recognise this as a brief respite, it’s fantastic all the same.

Monday was the final leg, where we battled through a full day of cell biology, starting with two consecutive hours of the different molecular diagnostic tools and then spent the afternoon carrying out PCR and Gel Electrophoresis.

I’m the kind of person who likes to do practical stuff, I like to learn with my eyes and my hands (this, apparently, is known as visual-kinaesthetic learning). And I learn best by seeing the things that I’m learning about. When it comes to anatomy, this is perfect. The more 3D models I’m given, the more I add to the 3D dog in my head. But molecular cell biology is an invisible art, that doesn’t always follow specific rules. The information is disjointed and slippery for me, and the practicals are pretty pointless.

Although it felt kinda awesome to be in my white coat and purple gloves, pipetting things into small vials and spinning them in machines at unfathomable speeds, I didn’t learn anything. Clear liquid was put into clear liquid and whizzed around. Then I put it into a slab of gel and was told that in practice, electrophoresis would follow but that they would do that themselves.

Similarly, the enzyme practical we did involved a light spectroscope, where I added clear liquid to clear liquid, added cloudy liquid at the last minute and hurried to put it into a machine. The process gave me numbers to plot on a graph, I fiddled with them mathematically and I got information about the enzymes. But guess what? I could explain PCR, gel electophoresis and light spectroscopy, and interpret enzyme graphs, at A-Level.

So yeah, it was cool to do what the molecular scientists do, but not for two 3-hour long sessions. But every course will have its superfluous bits and I guess it was two afternoons off to do mindless tasks, which is something of a relief.

However, on the anatomy front, it was all go. The last head dissection was a trip deep into the canine head, and was way harder than I had expected.

In the 3D models and the textbooks, muscles and structures are clearly defined, brightly coloured and easy to identify. But real life (or should I say real dead) is not so easy. Muscles lay under and over each other, they’re dull in colour and covered in fibrous fascia. All of this adds to the challenge of finding and identifying them, but the harder it is to find something, the more profound a learning experience it is when you do find it.

But what stood out for me during this session was the deviation I took from any normal person’s concept of the word ‘dissection’. This word, with its connotations of fine cutting, delicate removal and careful exploration, contrasted completely to what I did this week.

In other words, today was the day we were required to cut through bone and remove the right mandible from the head. The instructions explained that this should be done by disengaging the muscles from the surfaces of the mandible, and then cutting through the joint capsule.

Having spent ages trying to remove muscle from bone, and failing to uncover the capsule of the temporomandibular joint, a decision was made: pull it out.

After we had freed the front end by whacking through the mandibular symphysis with a hammer and chisel, I took hold of the jawbone. Working it backwards and forwards to loosen the joint, the teeth digging into my hand, there was a tear and a crack – and the jawbone was out of the head and in my hand. Surgery, I think, is the word.

Looking at the tough, fibrous muscle that I’d forcefully detached from the mandible, it came as no surprise the biting force a dog can deliver. Bit of veterinary anatomy for you: Three muscles work together to close the jaws of a dog: temporalis, which covers the entire top of the cranium and tucks in behind the zygomatic arch to attach to the jawbone; pterygoid, which glues the bottom of the skull to the top of the jaw; and masseter, the enormous cheek muscles. Originating on the skull and finishing on the mandible, these muscles make up a huge proportion of the dog’s head, and serve to grip like a vice. One measly muscle know as digastricus pulls backwards on the mandible to open it. But in evolutionary terms, canines don’t need the strength to open, they need the strength to close – and not let go.

Great, so the mandible was out. But it had left a royal mess behind. There were so many muscles. We did manage to give names to them all in the end, so the mission was accomplished.

But vet school doesn’t hang about. Done with the head, our lecturer moved on and gave us a two-hour long blast of forelimb anatomy. Bones, joints, ligaments, tendons, nerves… the works. My job between then and tomorrow is to learn this stuff. So far, I feel like I’ve conquered the bones and bony prominences, tendons, ligaments and some of the major muscles. At the moment, I’m trying to learn the nerves… not an easy task. One thing that does make this task more entertaining is that, particularly in the antebrachium (forearm), I can use myself as a specimen! A particularly difficult nerve, the radial nerve, has lots of branches and innervations. But quite quickly I discovered that I can trigger my own radial nerves and feel the muscles responding.

If you fancy it, you can have a go. Stick your left forearm out forwards, and close the fingers of your right hand across the top with your thumb across the bottom, just below the elbow. Bend your wrist backwards, and a muscle group close to your right knuckles will contract. This is extensor carpi radialis.

Relax. Stretch your fingers out straight. A group slightly to the left will contract, these are your digital extensors.

Relax. Bend your wrist to the left. A group on the far left will contract. This is ulnaris lateralis. In short, the radial nerve is responsible for many of the actions that extend the joints, including the elbow, wrist and digits.

We’re not so different from our doggy cousins after all.

On Thursday, I was back out at Langhill, where we were talked through the multiple ongoing tasks we had to complete as part of the Animal Life & Food Safety course assessment. One of these is to track our adopted cow’s statistics through the year, and ultimately make a decision whether we would cull her or keep her. It’s the kind of thing where you leave your sentiments at the door.

But to get our hungover and exhausted minds working, we were given 5 minutes to go around the room and memorise numerous different breeds of sheep, breeds of cow and feedstuffs. Then, we were quizzed. With a respectable 33/48, I was pretty pleased with myself. Of course, there are students from farming backgrounds who did considerably better. But I reckon I could top them on species of tropical fish.

Thursday’s finale was a whole-hall fire alarm that erupted moments before I wanted to go to bed. All that fuss, effort and freezing my bum off in the dark was for nothing, because the all-clear was given and no fire services arrived. Since this is university, the cause could be any number of things, from weed smoking or toasters, to body sprays and over-zealous use of hair straighteners. The mind boggles.

Next week promises to be interesting, with limb dissections, milking practicals and a lecture simply entitled “Pig”. Join me later and we’ll find out why!

For now, I’ll share with you the beauty I’m privileged to see every evening…as1 as2

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