In alarm stage, heroes are born

Nervous system acts to relieve pain and prevent blood loss


July 29, 2005|By Mariana Minaya | Mariana Minaya,SUN STAFF

People in life-threatening predicaments can sometimes perform feats that seem impossible, exhibiting superhuman strength or surviving for days in the wilderness to save themselves or others.

For example, it's hard to believe a 4-year-old girl could keep her stricken grandfather afloat for several hours, but it happened just a month ago in Herring Bay, a part of the Chesapeake, when the 60-year-old man began sinking while swimming and the girl supported his body until rescuers arrived. Although he drowned, she escaped with only a case of hypothermia.

In similar extreme situations, women have been known to lift a car to save a life, and hikers have moved huge boulders.

With a broken pelvis, model Petra Nemcova spent hours clinging to a palm tree after she and her boyfriend were swept away by the Southeast Asian tsunami in December. He was killed, but she survived, even after feeling her bones break several times. She was one of many tsunami survivors who struggled between life and death.

How do ordinary people perform such feats of strength and endurance?

Scientists credit a part of the nervous system that kicks in and devotes all of the body's available resources to the emergency. It's known as going into alarm stage, said Sonja Batten, coordinator of the trauma recovery program at the Baltimore Veterans Affairs Medical Center.

The autonomic nervous system, stimulated by stress, can cause the heart to beat faster and respiration to increase, thereby getting more blood, oxygen and energy into the muscles, Batten said. It also halts functions such as digestion, which are unimportant during an emergency, and diverts blood flow from the skin to prevent potential blood loss.

The system can release the body's natural opiates to relieve pain. That explains why soldiers or policemen who have been wounded can sometimes carry on with their duties - often until someone else notices they've been hit.

"People can be shot in the head or the leg and not realize until after the dust settles and they're able to take stock of what's going on," she said.

In alarm stage, the brain also releases a cascade of neuro-chemicals such as adrenaline, noradrenaline, and cortisol, Batten said.

Immediately, the nervous system sends signals to individual organs. Vision narrows to focus on a threatening object. Memory can become more selective, and perception of time can change, causing some people to feel as though seconds were stretched into minutes or compressed into an instant.

The reaction is also known as the fight or flight response.

'A primal response'

"It does not require conscious decision," said Robert Kass, chairman of the pharmacology department at Columbia University. "It just takes over, in a sense. It's a primal response."

As the body prepares for combat or escape, its resources are pushed to the extreme. "All the systems are optimized, and you're performing at the optimum level that your body is capable of," Kass said.

That's when people perform feats of strength or survival, like Aron Ralston, a hiker who amputated his own hand when it was pinned under a boulder in a remote Utah canyon, or the Georgia woman who lifted a Chevrolet Impala off her son in 1982, saving him from serious injury.

Unfortunately, there can be consequences to such extraordinary feats of strength, according Thomas Scalea, physician-in-chief at the University of Maryland's R Adams Cowley Shock Trauma Center.

"If you lift a car up, it doesn't mean you haven't strained your back," he said. "It just means you ignore that because you're focused on lifting the car off your kid or keeping your grandfather alive."

Not everyone may be capable of such feats, and Columbia University's Kass said genetics may affect the reaction to signals sent by the brain."We're just at the beginning of this next phase of [investigating] how gene variations work," he declared.

Laurence Gonzales, author of Deep Survival: Who Lives, Who Dies and Why, has another theory. He suggests that people are socialized to control their natural, animal strength. But under stress, they, can tap into it.

He said the rational part of the brain, the neocortex, is turned off in a dangerous situation, and the limbic - the emotional and more animal part of brain - takes charge.

Proving how complete the switch can be, he said, is the fact that people may become incapable of solving the simplest problems, such as recalling 911 in an emergency.

"People end up dialing 411 instead because that's what they're used to dialing," he said. "That's how effectively the limbic system `turns off' the neocortex. That's how stupid you get."

Humans are capable of incredible strength but are taught to suppress it, Gonzales said, because thinking has usually been more beneficial than brute strength for the species' long-term survival. The neocortex may have evolved when early humans found it better to stop and think where to aim before they threw a rock at an animal during a hunt, he said.

Brawn vs. brain

Young children are very strong for their size, he said, because they haven't yet learned to moderate their strength and use their thinking capabilities first. It is often the acquired belief that humans are incapable of great feats of strength that makes people unable to perform them, he said.

"People are surprisingly strong," he said. "They're constantly inhibiting their strength through their neocortex."

Gonzales points out that muscles in chimpanzees and humans are similar, so we should be capable of the same actions. Yet an average 5-foot tall, 100-pound chimp is much stronger than a typically larger human. While working in a lab, Gonzales said, he saw chimps who could crush truck tires with their hands.

When the neocortex is turned off during an emergency, people don't stop to think that they can't lift a boulder or car. Their bodies, in survival mode, just do it.

"They realize the full potential of their muscles," Gonzales said. "What you think is possible makes a big difference."

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