The internet turns up millions of pages of speculation, but no Straight Dope. People have been removing the tongues from mammals, and each other, throughout human history. There has to be some scientific data on this somewhere.
Will an untreated, severe, lingual laceration, really result in bleed-out of an otherwise healthy human?
Or will lingual trauma facilitate swallowing the tongue sufficiently to cause asphyxiation?
What does the science say?
PS: I couldn't find a tag for "trauma".