Giraffe dissection 3: that front limb ain’t done yet!

Yesterday, Sebastian and I started getting the muscle architecture data we’d previously not been measuring. John taught us how to do that, then left us to our own devices. But first, he pulled the cooked-clean scapula out of the boiler. Here we are: John and me proudly presenting the first completely cleaned bone of our giraffe:

Then, it was time to tackle the individual muscles we had cut off the day before.

John showed us what to do on the teres minor, then Sebastian got to “play” with the teres major. When it was my turn John said: “Let’s pick a hard one for you…. let’s take the biceps next” – AARGH! I could have done without that! But it turned out to be easy and fun!

Here’s the set-up:

A board to put the muscle on that keeps it from slipping around and doesn’t blunt the knife, a knife to do the cutting, scales (on the left, barely visible), a tape measure, and something to measure angles with. Out of view there are a clipboard, a pencil, and a stack of ready-made data sheets for noting down muscle length, weight, tendon length, fascicle length, fascicle angles and so on. Oh, and you need a camera, obviously…..

We took pics and measured a bit, then it was time to cut the muscle down the middle. Here’s the results:

Remember I said the insertion tendon was massive and tough? I wasn’t kidding….. Luckily, the blade flying off didn’t hurt anyone!

We later proceeded to cut the muscle up some more, which included cuts along the length of the belly I didn’t hit the first time around. Here’s what it looks like:

Lovely, hu? That’s what I call a multi-pennate muscle! In fact, some of those fibers are not even 2 cm long, while some in the other belly are over 20 cm (going by memory here, so I may be off a bit). The pennation angle is crazily high, too: on average it is between 40° and 45°. As John put it: “That is one major force-producing muscle! Wow!”

We spent the rest of the day doing the same stuff with all the other muscles. To be honest, I feel we were rather slow, especially with those muscles that come down to the limb from the neck or thorax, because they were – let me say: not in the best of shapes, especially because of the time they had to dry out. But we’re learning! 🙂