The Iguana Files: Part 1

     Third day in the lab! Today I started dissecting my first iguana specimen, aptly named "Iguana 1." I first skinned both forelimbs, the upper back and upper chest. This revealed all the muscles of the forelimb and their attachments throughout the back and chest. Skinning took longer than expected due to the weird position of the lizards arms. They were lying flat against its sides, making it hard to reach the skin laying against the body. It took some bizarre maneuvers of the scalpel and the help of gravity, but eventually I got all the outer layer off. However, I ended up damaging the flexor carpi ulnaris of the left forelimb. This is the muscle on the forearm that allows the wrist to bend on the thumb side. 
     After the skin came off, I had to separate the muscles of both limbs. There are several ways of doing this. The first is called the "scissor method," which requires sticking a pair of scissors between two muscles and gentling opening them to pull them apart. This allows the dissector to feel if there is a large resistance, which would indicate that the two muscles you thought you saw were, indeed, one muscle. Another method is using a scalpel and a pair of tweezers to slowly cut the muscles apart. This method allows for a lot more mistakes because a scalpel will cut through almost anything, easily. The last is using a dull probe to push along the boundaries between two muscles and separate them. I used all three with my lizard today. 

This is one of the sources I'm using to identify the muscles of the forelimbs. There are a lot more than are shown though. :(

     I then began photographing the limbs. I placed numbers on those muscles that I identified. These numbers corresponded to a list of muscles in the forelimb, which obviously allows me to easily identify the muscles in the pictures. I also photographed the limbs without numbers, for more reference. On Friday, Dr. Fisher and I will begin removing the superficial muscles of the forelimb to reveal the deep ones and eventually the bone and muscle attachment points. That's all for now. 

AA