Cooking with Muscles

I remember the day in class that Amy showed us a slab of meat (online) and how the white lines were actually sections were muscles have been cross cut.

I saw this while adventuring out in Wisconsin's wilderness and cooking up a 2" arm roast over a campfire. If you pick up the meat/muscle before it is cooked, it will hang and begin to separate from itself. I found this interesting, because you can also see the muscle structure and how it intertwines. It is also interesting to think how they would flex, extend, and contract. I wonder how holder peoples muscles look like in comparison to babies or even athletes vs couch potatoes.