696 THE SYMPATHETIC NEEYES. 



Dates in the semilunar ganglion, frequently sending some filaments to the 

 renal plexus and the suprarenal body. 



The splanchnic nerve is remarkable from its white colour and firmness, 

 which are owing to the preponderance of the spinal nerve-fibres in its 

 composition. 



In the chest the great splanchnic nerve is not unfrequently divided into parts, and 

 forms a plexus with the small splanchnic nerve. Occasionally also a small ganglion 

 (ganglion splanchnicum) is formed on it over the last dorsal vertebra, or the last but 

 one ; and when it presents a plexiform arrangement, several small ganglia have been 

 observed on its divisions. 



In eight instances out of a large number of bodies, Wrisberg observed a fourth 

 splanchic nerve (nervus splanclmicus supremus). It is described as formed by 

 offsets from the cardiac nerves, and from the lower cervical as well as some of 

 the upper thoracic ganglia. (" Observ. Anatom. de Nerv. Viscerum particula 

 prima," p. 25, sect. 3.) 



SMALL SPLANCHNIC NERVE. 



The small or second splanchnic nerve springs from the tenth or eleventh 

 ganglia, or from the neighbouring part of the cord. It passes along with the 

 preceding nerve, or separately through the diaphragm, and ends in the 

 coeliac plexus. In the chest this nerve often communicates with the large 

 splanchnic nerve ; and in some instances it furnishes filaments to the renal 

 plexus, especially if the lowest splanchnic nerve is very small or wanting. 



SMALLEST SPLANCHNIC NERVE. 



This nerve (nerv. renalis posterior Walter) arises from one of the lowest 

 thoracic ganglia, and communicates sometimes with the nerve last described. 

 After piercing the diaphragm, it ends in the renal plexus, and in the inferior 

 part of the coeliac plexus. 



LUMBAR PART OF THE GANGLIATED CORD. 



In the lumbar region the two gangliated cords approach one another 

 more nearly than in the thorax. They are placed before the bodies of the 

 vertebrae, each lying along the inner margin of the psoas muscle ; and that 

 of the right side is partly covered by the vena cava. 



The ganglia are small, and of an oval shape. They are commonly four 

 in number, but occasionally, when their number is diminished, they are of 

 larger size. 



Connection with spinal nerves. In consequence of the greater distance at 

 which the lumbar ganglia are placed from the intervertebral foramina, the 

 branches of connection with the spinal nerves are longer than in other 

 parts of the gangliafced cord. There are generally two connecting branches 

 for each ganglion, but the number is not so uniform as it is in the chest ; 

 nor are those belonging to any one ganglion connected always with the 

 same spinal nerve. The connecting branches accompany the lumbar arte- 

 ries, and, as they cross the bodies of the vertebrae, are covered by the 

 fibrous bauds which give origin to the larger psoas muscle. 



BRANCHES. The branches of these ganglia are uncertain in their number. 

 Some join a plexus on the aorta ; others descending go to form the hypo- 

 gastric plexus. Several filaments are distributed to the vertebrae and the 

 ligaments connecting them. 



SACRAL PART OF THE GANGLIATED CORD. 

 Over the sacrum the gangliated cord of the sympathetic nerve is much 



