I just saw this topic on an episode of Deer and Deer Hunting, they said "there is no black area" also they explained when you cut open a deer and see the space between the lungs and spine is because the lungs are deflated, when the deer is alive the lungs expand almost 3xs their size. Also something that i thought was interesting is that the inside of the deer's chest cavity is pressurized so if something punctures it and causes the chest to depressurize the deer will eventually die.