A punch or kick to the head seems like a logical way to obtain a quick knockout, but the liver shot is a strangely powerful organ attack that can drop an opponent to the canvas just as fast.
Liver and The Nervous System
The capsule that surrounds the liver contains a multitude of nerve fibers, which link it directly to the autonomic nervous system. This is the part of the nervous system that controls involuntary actions such as heartbeat, the widening or narrowing of blood vessels and breathing. This system also reacts in “fight or flight” situations and regulates the internal organs including stomach, intestines, kidneys, bladder, lungs, pupils, heart, glands and the liver.
Play-by-Play of the Collapse
When there is a sudden impact to the liver itself the organ stretches, which causes a pressure change. The events that follow are operated through the autonomic nervous system, meaning that they are involuntary and thus unstoppable.
- Nerves signal a sudden dilation of blood vessels all over the body, with the exception of the brain.
- Heart rate drops suddenly
- Blood pressure dramatically plummets
When blood pressure is decreasing the body tries to take control. It is the combination of the open blood vessels and decreased heart rate that causes the drop. When the two issues cannot be resolved, emergency actions are taken and the body fights to maintain flow to the brain by putting the body in a flat or recumbent position. This survival tactic is the reason for the collapse.
Liver Knock Out
If the sudden trauma to the liver is severe enough the fighter could lose consciousness. The set up is the same for the general collapse, but in this situation there is also a constriction of blood vessels in the brain. If blood pressure drops suddenly enough the brain thinks it is not receiving enough blood pressure and further restricts the flow as a precaution, causing loss of consciousness. Some fighters have reported that after a liver shot, their mind is clear, but their body is non-functional.
Why the Liver?
This phenomenon can occur with any of the organs, but the liver happens to be the most exposed. It slightly protrudes under the rib cage, which leaves it vulnerable. This protrusion has been attributed by some to the relatively recent evolution of the human body. The theory is that the liver has increased in size to meet our demand for its services, while our rib cages have not.