Functional characteristics of the autonomic nervous system

Many people don't know much about the autonomic nervous system. The so-called autonomic nervous system is of great benefit to human health. So many people want to understand the functions and characteristics of the autonomic nervous system in order to make themselves healthier. For your comprehensive understanding, let's take a look at its functions and characteristics.

The main functional characteristics of the autonomic nervous system are: ① The antagonistic effect of the sympathetic and parasympathetic nerves. The effects of sympathetic and parasympathetic nerves on organs that receive dual nervous system control are generally antagonistic. For example, the sympathetic nerves speed up the heart rate and slow down gastrointestinal motility; the parasympathetic nerves slow down the heart rate and strengthen gastrointestinal motility. But this antagonistic effect is complementary. In addition, sympathetic nerve excitement is often accompanied by secretion of adrenal medulla, so it is called the sympathetic adrenal system. Vagus nerve excitement is often accompanied by pancreatic islet secretion, so it is also called the vagus-islet system. From the perspective of energy metabolism, the function of the sympathetic nervous system can promote energy consumption, while the function of the parasympathetic nervous system can enhance energy storage. The two complement each other.

Because it is easier to store after consumption, and storage is for future consumption.

②Tension effect. In a quiet state, autonomic nerve fibers often transmit low-frequency efferent impulses to effectors, which have a slight and frequent stimulating effect, called the tonic effect. For example, cutting the vagus or sympathetic nerves that control the heart can speed up or slow down the heartbeat respectively. This shows that before being cut, the vagus nerve slows down the heartbeat, while the sympathetic nerve speeds up the heartbeat. However, the two comparisons vary depending on the animal species. For example, the sympathetic effect is stronger in rabbits, while the vagal effect is stronger in horses.

③ Sympathetic-adrenal activity and emergency response. When animals encounter various emergency situations, such as strenuous exercise, blood loss, and extreme cold, the body will undergo a series of phenomena in which the activity of the sympathetic-adrenal system is widely enhanced, which is called emergency response (stress response).

American physiologist WB Cannon proposed the emergency theory based on this reaction. These reactions include: accelerated heart rate, extensive contraction of skin and visceral blood vessels, bronchial dilation, accelerated liver glycogen decomposition, etc. Their physiological significance lies in mobilizing various potential forces of the body to adapt to drastic changes in the environment. If an animal's sympathetic nervous system is cut off, its ability to cope with emergencies is greatly weakened.

This article introduces the functional characteristics of the autonomic nervous system in detail. Therefore, for many people, in order to ensure that their autonomic nervous system can be healthier, they can learn about the functional characteristics of the autonomic nervous system through the above content. After understanding it, I believe that they can better protect their health in daily life.