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The sympathetic nervous system is one of the components of the autonomic system (the vegetative system), next to the parasympathetic system. It is a very important part of the human nervous system. Responsible for activities that we do not consciously control.
The structure of the sympathetic nervous system
The sympathetic nervous system is also called the sympathetic nervous system. The main centers of the sympathetic nervous system are located in the spinal cord. They are located between the C8 and L2-L3 levels of the core. Sympathetic neurons are located between the cervical and lumbar spine. Preganglionic sympathetic fibers extend from these parts of the spine. They reach the ganglia of the sympathetic nervous system between the C8 and L2-L3 levels of the core. In the sympathetic system, the following can be distinguished: the upper, middle and inferior cervical ganglion, the stellate ganglion, the thoracic ganglion, and the lumbar and sacral ganglia. The most important element of the sympathetic system is the sympathetic trunk, which consists of the ganglia of the sympathetic system connected by the nerve branches running between the ganglia. The sympathetic nervous system includes the cardiac plexus, the visceral plexus, and the upper and lower hypogastric plexus, among others. The structure of the sympathetic nervous system also includes the network of visceral nerves and the adrenal medulla. Sympathetic neurotransmitters contain specific substances: acetylcholine on the pre-ganglion ends and norepinephrine on the postganglionic fibers.
Functions of the sympathetic nervous system
The sympathetic nervous system performs a number of important functions in the human body. It is part of the autonomic system whose role is to mobilize the body. The sympathetic nervous system increases the ability to act. It is under his influence that a person becomes able to flee or fight. It is the sympathetic nervous system that is also responsible for experiencing stress. The sympathetic nervous system controls the following activities beyond conscious control:
- dilatation of the pupils,
- increased heart rate
- increased sweating,
- increased contractility of the heart muscle cells,
- rapid breathing,
- bronchodilation
- increase in blood pressure,
- slowing down of intestinal peristalsis and contraction of the sphincters,
- relaxation of the muscles of the bladder and urinary tract and contraction of the bladder sphincter,
- inhibition of blood supply to the intestines,
- increasing blood reaching the muscles
- increasing the breakdown of adipose tissue,
- increased glycogen breakdown,
- increase in blood glucose levels,
- inhibition of insulin secretion by the pancreas.
Symptoms of the sympathetic nervous system
Symptomatic disorders include, but are not limited to, disorders such as impotence, orthostatic hypotension, and disorders of sweat secretion (increased or decreased sweating). A malfunctioning sympathetic system is also possible problems with incontinence or difficulty in passing urine, constipation, fainting and dry mouth. Sympathetic disorders may arise as a result of various diseases, and treatment requires proper diagnosis of their cause.