Avian Anatomy

Our last anatomy lab was on avian anatomy, so we dissected chickens. Here is an account of some of the things I thought were interesting.

You'd be surprised how few feathers they actually have. When they're alive they're all poofy, but for dissecting they had us dip them in soapy water so that feathers wouldn't be floating everywhere all lab (I'm serious), and you can really see that there's not as many as you'd think.

Birds have a super massive keel on their bellies, part of their sternum. Imagine your sternum down your chest, but with a big fin. Most of  their bones are the same as mammals, but lots of things are fused. Most of their vertebral column is fused, which gives them stability and allows them to have less back muscles, which makes them lighter. The wishbone is their clavicle. Another interesting bony structure is the bone in their tongue--they don't have tongue muscles; the movement is conducted through their tongue bone.

Birds have a different voice organ than mammals, called the syrinx (we use our larynx). Something interesting I read is that songbirds and such that make a lot of complex sounds don't necessarily have a more developed syrinx or associated muscles.

Their brains are tiny, which I'm sure you already knew. What you might have not known is that their eyes are huge, way bigger than they appear because they aren't a sphere. Each eye is about the same size as the brain. Also their skull is kind of thick too, so if you're just looking at a bird and try to picture the size of their brain in their head, it's actually way, way smaller than you'd think just by doing that. They can have pretty super vision, but I don't think their brains do a whole lot else for them.

Birds don't have a diaphragm: they depend on moving their body wall to draw air into their lungs. So if you hold a bird so it can't move it's chest, it won't be able to breathe. They also have a pretty cool system, where air gets drawn into these air sacs and  then into the lungs and then into other air sacs before being exhaled, so that the air going into the lungs is always fresh. Being so efficient is why they can fly very high, where the oxygen is low.

Their gastrointestinal, urinary, and reproductive tracts all open into this one pouch and exit the bird through the same hole. They sort of have two stomachs--one that's glandular, and one that's super muscular (the gizzard). That's kind of neat because it actually utilises ingested stones to help grind up food. Their testicles don't descend (they stay inside the abdomen), and sometimes the only way to sex a bird might be using internal imaging. They also don't have a bladder.

If you look at the ovary, you can see a bunch of big red follicles, like the ones that will be tomorrow's egg and the next day's. They're super huge! And if you break one by accident, you get yolk everywhere. In our bird, it had actually had a ruptured part of its reproductive tract, so there was an egg that hadn't got its shell yet, and it was just hanging out inside the bird. It looked just like it would have if you'd cracked one and dropped it in.

The nerve that innervates their hind limbs passes over the kidney, so if they have kidney disease or a tumour or something, it can actually present as lameness.

Perching is a passive thing. When they bend their knees, it tenses the tendons that flex their digits, causing them to grip. It takes no energy for them to sit there gripping a branch, and if you want to un-perch them you have to straighten their legs.

Some birds, such as owls, have asymmetric ears so they can localise sound better. Also, birds have magnetite in their beak and neck muscles, which is an iron rich crystal that responds to the Earth's magnetic field. This gives them both directional and geographical location information.

Those are all the cool facts about birds I can think of for now, I hope you learned something.

You Have Been Warned

Last semester marked the end of general anatomy, though we still have comparative anatomy this semester. Having done the musculoskeletal system and thorax in first year, that left the head and abdomen. The division of learning was interesting: out of ten labs, seven were on the head, and three were on everything else.

I'm not sure who thought that was the best idea. If you ask me, they could probably have just made some sort of neuroanatomy/neurophysiology course to take the place of one of our useless ones (because sadly we have several that are a complete waste of time). It would seem to me that the abdomen is pretty important--think about how much a vet has to work with it, between the stomach and intestines, kidneys and bladder, and urogenital system. I'd imagine we're going to see a lot of spays/neuters, dogs swallowing things they shouldn't, horses with colic (abdominal pain), cats with urinary tract diseases, and everything else you can think of. Yet for some reason our learning of the anatomy of those things was all in one lab.

The last lab was so huge, in fact, that there was a giant warning page at the beginning of the preparation section and the dissection instructions. It very disapprovingly states that if you've gotten into the habit of not finishing, or even starting, the preparation sections, you had better get your act together because this module 10 is intense. It makes a point of reminding everyone that if you don't complete the preparation section and you get caught, you'll fail the lab.

Note: Writing this now since starting comparative anatomy, and looking at last semester's lab book, it saddens me to notice that lab 10 in it's massive enormity of reading, questions, and dissection, is still smaller than the work required for comparative anatomy. The first lab was 30 pages. The second lab was 40.

Slave Auction

As part of the fundraising for their halfway day--the day that is exactly half way through their degree, and they go off skydiving and partying and stuff like that--every year the third years hold a slave auction. At this event, groups of third year vets perform talent acts and then you can bid on them. If you win a group of slaves, you get them for two hours worth of work. The advertisements suggested having them clean your flat or be your best friend at a party and make you look cool. It is traditional for the other years to chip in and buy a set of slaves.

The average price for slaves was about $200, and they ranged between $100-$300. Everyone in our class gave the class rep $2, so with 100 people in our class that was just enough to buy one set of slaves. Our plan was to have them clean up after the First Year-Second Year party (that didn't actually happen so I'm not sure what we'll use them for). We kept getting outbid, and just barely managed to snag the last group for sale.

Most of the groups just did dances. One of them poked fun at our professors with rewritten lyrics. My favorite group was one that dressed in black morph suits, turned out the lights, and had glowsticks taped to their bodies in a stick figure shape. My second favorite was a bunch of people dressed up like cookie monster. I particularly liked this one because they had a huge amount of homemade cookies that they kept throwing into the audience. I got one.

One of the groups that didn't do a dance had this idea to sweeten the deal. You see, if you bid on them, you also got to take home your very own prosthetic leg. One of the bidders was a guy with crutches.

Another set of slaves was in the form of a barbershop quartet.

And, because it wouldn't be a vet event without random nudity, the audience somehow coerced the MC into taking his clothes off. I think that happened because the last set of slaves, a group of four guys, had already gotten some clothes off: when the bidding petered out, they kept offering to remove something if someone made a higher bid. Yeah, those were the ones we won.

Professors: Three Stances

Mr. Yorkshire accent who teaches nutrition is a cute old guy with messy white hair who not only uses the overhead projector, he doesn't know how to turn the computer projector off (so the computer's log-in screen isn't in the way) and has to have a student do it for him. He also calls the overhead transparents "acetates." I thought that was an acid with two carbons, but ok.

He has three, and only three, stances that he assumes during lecture.

Stance 1: This professor's most common state is with his hands level at his face. I think this is to emphasize his point. All his points, really. He looks into the middle distance, hands up to the sky, palms towards him, as if he's pleading with heaven, for pretty much most of the lecture.

Stance 2: This is interesting because his posture when he uses a pointer to point at the overhead is exactly the same every single time. He always turns to face the screen, puts his left hand on his hip, has the laser pointer in his right arm, and bends his right elbow keeping it level with his hip. He assumes this stance whenever he points to tables and graphs on his "acetates."

Stance 3: Whenever he needs to list something, such as benefits of a certain thing, his hands do drop below face level to a more normal position. He holds out fingers with his left hand and taps them with his right, just like anyone would do when counting out a list. Strangely, no matter how many points there are, he seems to get stuck on the third finger. If there are four points, he will just tap his third finger twice. It is important to note that these are fairly large, exaggerated list-counting-tapping movements.

A common cycle seen in his lectures is to begin with Stance 1 describing a topic, and switching to Stance 2 to point at a table that has data concerning this topic, then move to Stance 3 to list out key points. He will then return to Stance 1 to bring his point home, and the cycle restarts.