370 THE SYMPATHETIC NERVES. 



(Bradford) : the renal vaso-motor fibres probably end in the ganglia of the renal plexus 

 (Langley and Dickinson). 



(</) Afferent fibres from the abdominal viscera. 



The lowest part of the cord also contains : 



(//) Some of the motor fibres of the circular muscle of the rectum, proceeding from the 

 lower dorsal nerves. Together with fibres from the upper one or two lumbar nerves, they 

 pass by the aortic plexus to the inferior mesenteric ganglion. Associated with these are the 

 inhibitory fibres of the longitudinal muscle of the rectum (Fellner). 



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 on the front of the bodies of the 

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

 right side is partly covered by the vena cava, that of the left by the aorta. 



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

 number, but occasionally their number is diminished, and they are then 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 gangliated 

 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 arteries, and, as they cross the bodies of the vertebras, are 

 covered by the fibrous bands which give origin to the muscular fibres of the psoas. 



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

 Some join the plexus on the aorta ; others descending go to form the hypogastric 

 plexus. Several filaments are distributed to the vertebrae and the ligaments con- 

 necting them, 



CONSTITUTION OP THE LUMBAR PORTION OF THE SYMPATHETIC. 



Spinal fibres pass into the sympathetic from the upper one or two lumbar nerves, and 

 others descend in the cord from the lower dorsal nerves. For the most part they form a 

 continuation of groups of fibres which have been noticed in the account of the thoracic 

 sympathetic (p. 369), including vaso-con stricter and secretory nerves of the hind limb, pilo- 

 motor fibres, vaso-constrictor fibres of the abdominal vessels, and motor fibres of the circular 

 muscle, with inhibitory fibres of the longitudinal muscle of the rectum. 



Arising from the lumbar nerves only are the following : 



() Vase-motor nerves of the penis. The raso-comtrictor fibres probably pass from the 

 upper lumbar nerves into the sympathetic cord, whence they are mainly continued by pale 

 fibres through grey rami communicantes to the pudic nerve ; but it is stated by Francois- 

 Franck that some constrictor fibres run through the inferior mesenteric ganglion to the 

 hypogastric plexus, and that these are accompanied by a part of the vaso-dilator fibres of 

 the penis. 



(>) Motor fibres to the bladder, passing by the aortic plexus to the inferior mesenteric 

 ganglion, and thence through the hypogastric and pelvic plexuses, to supply the circular 

 muscle, including the sphincter. Associated with these there are probably inhibitory fibres of 

 the longitudinal muscle. 



(tf) Motor fibres to the uterus, taking a similar course to the foregoing. 



(Motor fibres to the vas deferens in the male, or to the round ligament of the uterus in 

 the female, were found by Sherrington in the monkey leaving the cord by the anterior roots 

 of the second and third lumbar nerves (corresponding to the first and second lumbar of man),, 

 and passing to their destination through the genital branch of the genito-crural nerve.) 



SACRAL PART OF THE GANGLIATED CORD. 



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

 in size, and gives but few branches to the viscera. Its position on the front of the 

 sacrum is along the inner side of the anterior sacral foramina ; and like the two 



