LUMBAR NERVES. 505 



brachial plexus. It receives a communicatirig branch furnished 

 by the sixth nerve. 



The eighth cervical nerve, larger than the preceding, also 

 passes to the brachial plexus. It sends a branch to the inferior 

 cervical ganglion. 



DORSAL NERVES (17 pairs). 



•The dorsal nerves, with the exception of the first, are all dis- 

 tributed in a sinoilar and very simple manner, as compared with 

 the cervical nerves. The superior branches, passing up between 

 the transverse processes, bifurcate, one branch being sent to the 

 spinal muscles and the skin of the dorsal region, the other being- 

 distributed to the longissimus dorsi muscle. The inferior 

 branches descend to the intercostal spaces, and pass along 

 between the pleura and internal intercostal muscles. Each of 

 these intercostal nerves, at its origip, gives one or two branches 

 to the sympathetic, and, towards its middle, a perforating branch 

 directed obliquely outwards to the skin, where it ramifies, and, in 

 its course, gives off muscular filaments. 



The inferior branch of the First Dorsal nerve goes almost 

 entirely to the brachial . plexus. It has no cutaneous division, 

 and its intercostal branch is very slender. 



The Second Dorsal nerve sends a large branch to the 

 brachial plexus. Its intercostal branch, more considerable than 

 that of the first, extends down to the sternum, and gives off 

 cutaneous twigs. 



The Third, Fourth, Fifth, Sixth, Seventh, and Eighth 

 Dorsal nerves pass to the extremity of the intercostal spaces, 

 and are prolonged into the pectoralis magnus and rectus muscles; 

 the last nine, after reaching the cartilages of the false ribs, are 

 continued into the walls of the abdomen, and under the internal 

 oblique, to the rectus, where they divide, one division going to 

 the substance of the muscles, the other furnishing twigs to the 

 skin of the abdomen. The Seventeenth Dorsal nerve fur- 

 nishes a large branch to the fleshy portion of the internal oblique, 

 and another which communicates with the first lumbar nerve. 



LUMBAR nerves (6 pairs). 

 The Superior branches of the lumbar nerves are distributed 

 to the muscles of the loins, and to the integument of the loins 

 and croup. 



