'To fight or not to fight'

Here are some interesting facts:

• Our body releases its own natural painkillers, called endorphins, to cope with injuries sustained during fight or flight.

• Our blood vessels near the skin become constricted, reducing blood loss should you be injured.

• Our sweat glands open, even when you are cold, ready to cool you should you need to run or fight.

• Our pupils dilate, to help us detect movement.

• Our hairs stand on end - so we become more sensitive to our environment.

• Our heart rate increases, our arteries constrict to allow maximum pressure of blood to the body, and our veins dilate to allow blood to return as quickly as possible to the heart. The result is that we go from pumping one gallon of blood, through our hearts, per minute to five gallons per minute. This is to make sure that our muscles will get as much oxygen as possible, should they need it.

• The respiratory system gears up for 'heavy breathing' should you need to run or fight.

• Glucose is released from the liver to create instant fuel.

• Blood vessels to the digestive and reproductive systems, and kidneys become constricted, thus shutting down unnecessary systems. Also, our mouths dry up. When fighting or running for your life, eating and sex will be the last thing on your mind.

• The vital blood supplies are diverted towards the main muscles of the legs and arms etc, as well as the brain. You need plenty of blood for the 'fast thinking' you might need to do - not much point in having energy in your muscles if you run in the wrong direction!

• Contents of the stomach/bowel/bladder may be jettisoned. This could distract the attacker and 'lightens the load' the body has to carry in escape.

The 'fight or flight' mechanisms listed above were invaluable in primitive times, when hunting prey or escaping from predators, and were essential daily activities; however, in a modern society they can cause problems; it's sometimes useful to have a fast thinking brain, but running over the horizon to escape a sabre-toothed tiger is less often required.

In the Lab Rats programme about fear, you saw how Zeron began to feel sick, breathe rapidly, sweat profusely and feel his mouth dry up - just dealing with a worm! With so many 'fight or flight' chemicals floating around the blood system, he became irritated, and started to shake violently as he wound up as taut as a violin string - his leg even started to stamp the floor! The only way he could find to calm down was to go for a run to get rid of the stress.

If you become stressed when working in an office, the 'fight or flight' response can take a toll on your heart and your general health because they are acting inappropriately for the conditions in which you find yourself. Because of this, over the long-term, stress can cause severe heart problems and other life threatening conditions. Since the stress response gets you ready for strenuous physical exercise, the best way to counteract it is to actually take some exercise - like I did when I climbed the crane. Exercise helps the body relax and uses up those dangerous chemicals that will otherwise carry on circulating in your blood. Strangely, a side benefit to fighting stress with exercise is you'll improve your fitness - an ideal antidote to modern living. So my advice is, if you have a stressful life - take more exercise with it!

  < previous   next > Page 4 of 5

Content last updated: 25/08/2005

About our expert

Dr Bundy Mackintosh is a Lecturer in Psychology at the Open University. Bundy moved to the OU in 2001, having worked for the previous 5 years in Cambridge at the Medical Research Council's Cognition and Brain Sciences Unit.
Bundy's research areas include Cognition and Emotion, especially the cognitive process involved in anxiety.

Comments