Medical School: Oops, I cut another nerve

Anatomy: how the heck are you supposed to tell what's a nerve, an artery, a vein, or just plain ligament?
Dissection is so much fun! I just love the smell of formaldehyde and the large quantities of cadaver juice we recover each day, and most of all - I love the fat that just oozes out of that 2 inch thick fat layer. yum. If it was unclear, that was sarcasm. But truth to be told, various group members keep on associating certain cadaver parts with food items! No!!! I will never be able to eat those things again... :(
The other day we tried to find the various branches off the axillary artery, which includes pectoral, acromial, clavical, and deltoid branches. I also wasn't aware that the arteries were white colored. I thought arteries had blood! Ugh, what makes it worse is that the nerves are about the same, but have different names. Great! And, it's exactly like an artery, but probably a tiny bit more translucent.
Well, to prevent me from cutting things, I decided to use my fingers. But to my dismay, I was pulling at the pectoral minor muscle and accidentally pulled the whole muscle off. oops!