Read this article.
http://www.nytimes.com/2006/11/02/world/middleeast/02medic.html?ex=1320123600&en=0105674773f788ee&ei=5088&partner=rssnyt&emc=rss Quote below.
"In one course, an advanced trauma treatment program he had taken before deploying, he said, the instructors gave each corpsman an anesthetized pig.
“The idea is to work with live tissue,” he said. “You get a pig and you keep it alive. And every time I did something to help him, they would wound him again. So you see what shock does, and what happens when more wounds are received by a wounded creature.”
“My pig?” he said. “They shot him twice in the face with a 9-millimeter pistol, and then six times with an AK-47 and then twice with a 12-gauge shotgun. And then he was set on fire.”
“I kept him alive for 15 hours,” he said. “That was my pig.”
“That was my pig,” he said."