The border cord is a concatenation of nerve cell body clusters that is part of the sympathetic nervous system. The individual portions of the border cord send sympathetic nerves to the neck, chest, sacrum, and abdomen. Like all other nerve branches, border cord-associated nerve branches may be affected by paralysis.
What is the border cord?
Ganglia are the medical term for clusters of nerve cell bodies in the peripheral nervous system. The clusters of nerve cells are also called ganglia and act like nodular thickenings. Within the central nervous system, physicians often call the corresponding thickenings nuclei rather than ganglia. The border cord is a concatenation of different ganglia in the peripheral nervous system. The structure is known in medical terminology as the truncus sympathicus and contains up to 23 autonomic ganglia. The concatenation extends from the base of the skull down to the coccyx and runs in a paravertebral direction adjacent to the spinal column. The individual border cord ganglia are called either cervical ganglia (ganglia cervicalia), abdominal ganglia (ganglia lumbalia), coccygeal ganglia (ganglia sacralia), or thoracic ganglia (ganglia thoracica), depending on their position. The entire border cord is part of the sympathetic nervous system and thus belongs to the autonomic nervous system. Different nerve branches originate from the border cord. The nerves cardiacus cervicalis superior, medius and inferior: run to the heart, for example. The vital tasks of the assigned nerves explain the assignment of the truncus sympathicus to the autonomic nervous system.
Anatomy and structure
In its gross structure, the border cord consists of four distinct areas: the cervical, thoracic, lumbar, and sacral regions. In the cervical region, three distinct ganglia lie within the deep cervical fascia dorsal to the carotid vein. These three ganglia are called the cervical superior and middle ganglia and the stellate ganglion. A border ganglion runs posterior to the subclavian artery. A second portion extends into the thoracic cavity. The lowest cervical ganglion is called the cervical inferior ganglion and unites with thoracic ganglion 1 to form the stellate ganglion. The thoracic ganglia are located in the border cord of the thoracic region. They are located on the heads of the ribs and are covered by the pars costalis. Intercostal vessels and intercostal nerves cross the structure. The border trunk portion of the lumbar region contains four ganglia lumbalia medially, originating at the psoas major muscle. The sacral region portion of the truncus sympathicus carries the ganglia sacralia, which lie medial to the foramina sacralia at the os sacrum. The border cord takes its termination in the unpaired ganglion impar with immediate localization on the coccyx.
Function and Tasks
The limiting cord is a part of the sympathetic nervous system. The sympathetic nervous system is principally intended to enhance the performance of the organism. The technical term for this is ergotropy. Via the sympathetic nervous system, the body achieves high performance readiness. From the evolutionary biological point of view, the activity of the sympathetic nervous system prepares the organism for attack, flight and other extraordinary efforts. All functions of the sympathetic nervous system are also known as stress reactions of the body and perform vital tasks. For this reason, the sympathetic nervous system is counted in its full extent as part of the autonomic nervous system. The borderline nervous system also has performance enhancement as its task. The sympathetic nervous system controls various organs of success through the concatenation of different ganglia. The plexi carotici associated with the structure give rise to sympathetic fibers that innervate organs of success in the region of the head. Through this structure, the sympathetic nervous system can influence increases in the performance of the organs of the head. The nervi cardiaci run to the heart and thus serve to increase the performance of the cardiovascular system. Sensory branches are also associated with the border cord, such as the rami interganglionares, which connect the individual ganglia of the truncus sympathicus. The truncus sympathicus is also connected to the spinal nerves via the rami communicantes. The rami cardiaci thoracici provide postganglionic fiber connections to the heart, and the splanchnic nerve major connects the border cord to the abdominal aortic plexus via preganglionic fibers from Th5 to Th9. The border cord is also connected to the thoracic aortic plexus via the unnamed branches. This aortic plexus sends branches to the lungs and esophagus.The sympathetic nervous system can also reach the iliac artery and the organs in the pelvis via the limiting cord. Thus, the main task of the sympathetic trunk corresponds to a mediation of performance-enhancing action potentials of the sympathetic nervous system. The border cord mediates these nerve excitations to the target organs, thus preparing the organism for exertion.
Diseases
Like all nerve branches, border cord-associated nerve branches can be affected by damage and resulting paralysis. As a result of such paralyses, the sympathetic nervous system is no longer able to influence the corresponding organs. The autonomic nervous system is thus thrown out of balance. The parasympathetic influence can no longer be counterbalanced by the sympathetic nervous system. A relatively well-known symptom complex from this area is Horner’s syndrome. The phenomenon is characterized by miosis, enophthalmos and ptosis and may be due to various causes. Usually, the symptom complex is preceded by paralysis of sympathetically innervated portions of ocular smooth muscle. Such paralysis may be due to mechanical injury, or may be caused by Pancoast tumors and any other damage to the stellate ganglion. Left-sided Horner’s syndrome is manifested by three symptoms. The dilator pupillae muscle fails. The same is true for the superior tarsalis muscle and the orbitalis muscle. Already in the gaze diagnosis the phenomenon shows up in an attenuated mydriasis. Much more severe than Horner’s syndrome is the so-called neuroblastoma, a tumor with localization within the border cord. Patients with neuroblastoma often also present with Horner syndrome, but it is usually associated with many other symptoms.
