MEDICAL JARGON BUSTER

SCIENTIFIC terms decoded. This week: Sympathetic nervous system THE sympathetic nervous system is one of two parts of a wider structure called the autonomic nervous system which controls many of our involuntary bodily processes such as heartbeat and breathing. The other part is the parasympathetic nervous system, and they work in conjunction.

The sympathetic side is responsible for our ‘flight or fight’ reactions — for example, it increases heart and breathing rates, blood pressure and pupil diameter at times of stress or exercise (the parasympathetic branch will exert opposite effects). It means we are more prepared in such situations; our heart beats stronger and faster, our breathing is made more efficient, and areas which are not critical at that moment — such as the digestive system — are inhibited so that more energy can be spent elsewhere.

The term ‘sympathetic’ was first used by Danish anatomist Jacques-Benigne Winslow in the 1700s, who coined the term in reference to parts of the body ‘subject to a common nervous influence’. The word sympathetic has origins in the Greek word sympathes, meaning to ‘have a fellow feeling’.