How Emotional Stress Affects us Physically
Facts of the heart of the average adult heart:
- Beats 72 times a minute
- 100,000 times a day
- 2.5 billion times in a lifetime
- Weighs 250-350 grams
- Pumps over 9,000 litres of blood through 60,000 miles of blood vessels every day
- Is made of cardiac muscle, which never tires
Dr Sean Roe, from the Centre for Biomedical Science Education at Queen's University Belfast, explains what causes the heart stress and some of the factors that influence the results.
"The heart is controlled largely by two centres in the brain," said Dr Roe.
"The sympathetic 'fight or flight' response or the parasympathetic 'rest and digest' response.
"On occasions that require extra cardiac output the sympathetic nervous system kicks in, which speeds up the heart. Cardiac output, which is the amount of blood put out by the heart every minute, increases allowing the additional demands to be met.
"Alternatively when someone is relaxing, the parasympathetic nervous system is to the fore, reducing cardiac output by reducing heart rate, and increasing blood flow to the digestive system, taking it away from the muscles.
"Anything that increases fight or flight, such as exercise or emotional stress, will increase stress on the heart."
Harder, faster, stronger
Cardiac function is related to fitness and age. The better your heart is at pushing blood around the body, the less relative stress it will be under when your heart rate goes up.
Dr Roe explained how exercise can help the heart cope with stress.
"One of the effects of training is to increase the volume of cardiac chambers. To increase cardiac output a certain amount, a fit heart would need to increase heart rate only a small amount compared to an unfit heart, because the fit heart is pumping more with each beat."
"How stressful you interpret the situation to be would contribute to how fast your heart rate goes.''
Reference: http://www.bbc.co.uk/science/0/22488580
