Tasks of the sympathetic nervous system | Sympathetic nervous system

Tasks of the sympathetic nervous system

The sympathetic nervous system is part of the autonomous nervous system, i.e. the nervous system that functions independently of the brain. It represents the activating part. This means that it reacts in situations that can be potentially dangerous and adjusts all body functions to a possible fight.

Nowadays, humans rarely get into situations that are actually life-threatening. Nevertheless, the sympathetic nervous system is used, and always when we are stressed. The sympathetic nervous system is responsible for the heart beating faster and the blood pressure rising, thus ensuring an increased blood supply.

Our airways dilate so that we get more oxygen. The vessels that supply the intestines with blood are narrowed in order to make the blood available for other organs, such as the brain, since digestion only plays a minor role in stressful situations anyway. The pupils are dilated so that one can see better. In addition, there is increased sweat production and energy reserves such as fat deposits are reduced so that energy-providing substances such as fats and carbohydrates can be used in the muscle.

Hyperfunction of the sympathetic nervous system

An overfunction of the sympathetic nervous system can be the cause and symptom of various diseases. For example, in the case of Raynaud’s disease, hyperfunction is the cause; in the case of pheochromocytoma, it is the symptom. However, the effects on the body are the same in both situations, of course always within the scope of deviations that can occur within a disease.

For example, blood pressure sometimes rises to such an extent that vessels become completely blocked and the affected areas are slowly undersupplied. This can lead to massive sweating, restlessness, insomnia, severe headaches and digestive problems. Depending on the disease, further specific symptoms may then occur. All this explains why the correct diagnosis of some diseases can therefore be very difficult.

Tasks of the parasympathetic nervous system as adversary

In contrast to the activating function of the sympathetic nervous system, the parasympathetic nervous system is responsible for regeneration and digestion. After escaping the stressful situation, our body relaxes again and starts to replenish energy reserves by stimulating digestion. This is done by dilating the blood vessels to the intestine, allowing more than the minimum amount of blood to pass through that is needed to maintain the intestine.

Also the vessels leading from the intestine into the body are widened, so that all absorbed nutrients can be processed and stored directly.The heartbeat slows down, blood pressure drops and the diameter of the airways is reduced. The sympathetic and parasympathetic nervous systems can therefore only be active in parallel to a limited extent. Which of the two is mainly needed depends on our environment and our personal perception.