Spinal nerves are important elements of the human nervous system. Different diseases can limit the function of the spinal nerves. If symptoms exist, medical attention should be consulted within a short time frame to avoid serious disorders.
What are spinal nerves?
The spinal nerve is the nerve pathways in the spinal cord. The spinal nerve is located in the spinal canal of humans and is responsible for transmitting information between the spinal cord and peripheral nervous system. The peripheral nervous system includes both the voluntary and involuntary nervous systems:
- The involuntary nervous system involves bodily functions and movements that are not consciously controlled, such as the heart muscles.
- Through the voluntary nervous system, it is possible for people to perform certain activities based on their own will, such as the movement of skeletal muscles.
Humans normally possess 31 pairs of spinal nerves. Their names result from the respective names of the vertebrae that can be located above them. The spinal cord connects the spinal nerves to the brain. The length depends on the individual body size. At equal intervals, nerve roots leave the spinal cord on either side. Once they leave the spinal cord, they bundle together to form the spinal nerves. Different diseases of the spinal nerves exist, from which serious consequences can result.
Anatomy and structure
The 31 to 33 pairs of spinal nerves slide through the intervertebral holes and run without interruption to the dorsal medullary division. This results in 8 cervical nerves, 12 thoracic nerves, 5 lumbar nerves, 5 sacral nerves, and one coccygeal nerve. Spinal nerves are mixed nerves, which include motor, sensory as well as vegetative parts. The pairs build up from an anterior as well as posterior nerve root. These are called efferent and afferent. The origin of the spinal nerve can be located virtually in the center of the spinal cord. As soon as the nerve root emerges from the spinal canal, it unites into a spiral nerve a few millimeters later. In the further course, three to four branches develop from the spiral nerves. The task of each branch is based on the motor or sensory supply of certain regions of the body. The posterior nerve root, i.e. the afferent pathway, has a different function than the anterior nerve root. Because spinal nerves function both efferently and afferently, they are mixed nerves.
Function and tasks
The task of spinal nerves is to transmit information from the spinal cord, which originates from the central nervous system, to the affected organs, muscles or other physical elements. At the same time, the information from organs and muscles is also transmitted to the spinal cord through the spiral nerves. Subsequently, the spinal cord can transmit the obtained information to the central nervous system. The efferent and afferent pathways are responsible for these two different tasks. The efferent part takes over the transmission of information from the spinal cord to the organs. The afferent parts, on the other hand, take information from muscles or organs and transport it in the opposite direction. In this way, for example, the movement of a muscle is possible. As soon as the central nervous system orders the activity of a muscle, the information reaches the spinal cord and then the efferent pathway. The information is delivered to the corresponding muscle, whereupon it executes the intended movement. These tasks also include the regulation of organic body functions. Thus, the nerve pathways also determine intestinal activity or the formation of digestive secretions. Both increase and decrease of production or function can be produced. In the afferent nerve pathway, on the other hand, stimuli such as touch are conveyed to the brain so that the affected person perceives them. In addition to touch, the sense of touch and the sensation of temperature, pain and position are also transmitted to the central nervous system. Furthermore, organs can also express themselves in this way. The stomach, for example, can transmit the degree of its filling. Each pair of spiral nerves is responsible for a specific region of the body.
Diseases and ailments
The spiral nerves perform important functions in everyday life. As soon as different diseases restrict them, it is of importance to consult a doctor. Particularly often it comes to the root syndrome. This is a disease of the nerve root. Different causes ensure that the nerve root is damaged, from which the conduction of information is reduced. Numerous complaints arise, such as pain, insensations, sensory disturbances and muscle weakness. In addition, the deafness of certain areas of the body cannot be ruled out. Several factors have the potential to irritate the nerves. These include, for example, a herniated disc or spinal stenosis. Most often, a narrowing occurs due to wear and tear diseases of the spine, causing nerves to be crushed. This cause is particularly common in the lower lumbar region or the region of the cervical vertebrae. In addition to irritation and crushing, there are also diseases that directly affect the spiral nerve. Diseases of this type are in most cases inflammatory in nature. Different pathogens can be responsible for an inflammation, for example the bacterium Borrelia burgdorferi or shingles. Guillain-Barré syndrome can also be to blame for inflammation. As soon as an inflammation of the nerve root develops, it usually also affects the spiral nerve, which emerges from the nerve root. Inflammation of a nerve root is called radiculitis. As soon as several nerve roots are inflamed, it is polyradiculitis. Because inflammation of a nerve root is usually associated in parallel with inflammation of the nerve, inflammation of the nerve often occurs at the same time and is called neuritis.
