The sympathetic nervous system is the sole source of autonomic nervous system activity to the musculoskeletal system. There is no parasympathetic innervation to the somatic tissues. The sympathetic nervous system has wide influence on visceral function, endocrine organs, reticuloendothelial system, circulatory system, peripheral nervous system, central nervous system, and muscle. Because the sympathetic nervous system is organized segmentally (Click here), it can be used in a maplike fashion to look for both alterations of afferent stimulus, and areas that might be influenced through manual medicine intervention.

From the perspective of the respiratory-circulatory model of manual medicine, the thoracic spine at levels T1-T6 assumes major importance in providing optimal functional capacity to the rib cage for respiration and circulation. The reason for this is that all of the viscera and soma above the diaphragm receive their sympathetic nervous system fibers from above cord level T-4, while all visceral and soma below the diaphragm receive their sympathetic nervous system fibers from T-5 and below. Understanding the segmental nature of this anatomy will help in relating identified somatic dysfunction to the patient's problem, and can lead the physician to give appropriate treatment to those areas of somatic dysfunction thought to contribute increased somatic afferent stimuli to cord levels with manifestations of increased sympathetic nervous system activity. Since many factors can affect sympathetic reflex activity, one of which is afferent impulses from segmentally related areas of the soma, it would seem reasonable to attempt to reduce aberrant afferent stimulus to hyperirritable sections of the sympathetic nervous system to reduce the hyperactivity of target end organs.

The heart of the sympathetic nervous system consists of a chain of interconnected, paired, paravertebral ganglia that lie adjacent to both sides of the vertebral column.(Click here). In the thoracic region these lateral chain ganglia are tightly bound by the fascia to the posterior chest wall and overlie the heads of the ribs. It is hypothesized that altered mechanics of the costovertebral articulations could mechanically influence the lateral chain ganglia. Rib raising is a manipulative technique for increasing mobility of the rib heads that results in a reduction in sympathetic outflow to organs. In addition to the paired, paravertebral ganglia, there are several prevertebral ganglia that are located in the abdomen and pelvis, relatively adjacent to the organs being innervated.

The paravertebral ganglia are connected to spinal nerves by a white ramus that contains sympathetic nerve fibers passing from the lateral horn of the spinal grey matter and through the anterior root of the cord. Sympathetic nerve fibers in the white ramus are known as preganglionic neurons because their cell body is located within the spinal cord. Within the ganglion, some of the preganglionic fibers synapse with what is refered to as a postganglionic fiber because their cell body is located outside of the spinal cord. Some postganglionic fibers return to the spinal nerve through the gray ramus, ulitimately traveling to, and influencing a somatic structure. Sympathetic nerve fibers contained within the white ramus are myelinated, while those in the gray ramus are unmyelinated, and this accounts for their respective names.

 

---

This product is intended for instructional use only. It is not designed for clinical or diagnostic purposes. The authors, producers, and publishers of these materials shall not be held liable for any loss and/or injury arising from the use of information and procedures contained in these programs.