Sorry Ray, but virtually nothing here is inside the science of killing...
Seven heart beats with a severed Aorta will put any animal on the ground... from lack of blood pressure.
Shock is absolutely not a measure of killing capacity short of CNS... No animal ever died from shock...
Blood pressure dropping completely disrupts brain function... and quickly... as above, seven heart beats with a severed Aorta kills immediately.
Brown bear heart rate at very low levels is a myth brought about by measuring hibernating bears' hearts... when awake and moving they have very ordinary heart rates...
Perhaps I was not clear, so here it goes again: a grizzly or brown on a charge from, lets say 35 yards away, can still chew you before it dies, because it will be on top of you within a couple of seconds. This is a maybe yes and maybe not thing, since every situation is different. Sometimes heart-shot animals such as moose and others take more than one step before dropping. But a brain shot usually drops the animal right there, then the animal dies from perhaps on to a few seconds later. For death from a loss of blood pressure to occur on any human or animal, it must be a complete blood pressure drop, not just blood loss. That's why we usually wait for a moose (for example) that is already on the ground, to expire. Otherwise we shoot it on the brain. Don't you think so? That's what I tried to say to the poster I was responding to. In other words, loss of blood does not always kill right away, but a total loss of blood flow kills faster. But it is not necessarily that a loss of blood pressure kills the brain. For example, if some blood from the heart is pumped to the brain just before the heart is blown to pieces, the brain still uses the blood that has already reached the brain to still send a signal for the animal to breath and move. The brain keeps on sending such signals until it has already spent all the blood that it already contains, unless you stop the CNS from functioning. A brain without blood can still survive a portion of time before it goes into a coma.
And about shock, I haven't said that shock kills. But the shock created when the bullet hits a body organ, or the area around the entry and exit wounds, violently shakes those areas. This leaves behind bloodshot flesh. The shock may not kill a large animal, but it sometimes stops the lungs from inhaling or exhaling, and even makes an animal shot near the brain pass-out for a moment, which then gets up and runs.
Better explained here:
http://www.health24.com/Lifestyle/Man/Your-life/Gunshot-wounds-20120721
