Has anyone done a virtual pig dissection lab before? if so, me out with this and i promise it's not the entire lab! (it's a fill in the blanks - warning: there's an image attached of a pig's innards! ) "circulatory system” 1. identify structure labeled 1. 2. why would the vena cava be classified as a vein? 3. within the capillaries of the lungs, gases are exchanged by diffusion; oxygen diffuses from the to the and carbon dioxide diffuses from the the