THM CERVICAL NERVES. 749 



branches, whicli are distributed to 'tbe muscles and integuments of the 

 superior cervical region. Among these, the superficial, which are almost 

 rudimentary in the two last pairs, reach the inner face of the splenius. The 

 others, deep and more voluminous, cross the semispinalis colli, and, dividing, 

 ascend between the great complexus and cervical ligament, to near the 

 superior border of that large elastic lamina. They generally intercommuni- 

 cate by several filaments, and in this way form a network on the inner face 

 of the great complexus, which Girard named the deep cervical plexus. 



Inferior Branches. — These branches augment in size from the first to 

 the last, and separate into two perfectly distinct groups. The divisions of 

 the first six cover the lateral and anterior parts of the neck, as well as the 

 muscles of the breast. Usually anastomosing with each other by long 

 communicating branches, they in this way form a vast nervous network 

 traversed by two important nerves — the spinal accessory and cervical 

 filament of the facial ; this is the superficial cervical plexus. The other two 

 are united with the preceding by a filament passing between the sixth and 

 seventh, soon becoming confounded with each other, as well as with the 

 two first branches of the dorsal region ; they constitute, in common with the 

 latter, the brachial plexus. 



Without saying any more as to the disposition of this double plexus, we 

 will pass to the particular description of each cervical pair of nerves. 



First. — Deeply situated beneath the transverse process of the atlas, this 

 nerve leaves the anterior foramen of that vertebra, and accompanies the 

 occipital artery and vein to place itself immediately between the anterior 

 small rectus capitis and rectus lateralis muscles. It then crosses the anterior 

 great rectus capitis and the spinal accessory nerve, which it separates ; and 

 arrives, after describing a slight curve forward, near the thyroid gland, 

 finally entering the subscapulo-hyoideus by several terminal divisions. 



Near its origin, this inferior branch of the first cervical nerve furnishes 

 collateral ramuscules to the three recti muscles. Lower, it is in communica- 

 tion with the superior cervical ganglion and the spinal accessory nerve by 

 several filaments. At the carotid artery, it sends forwards, to the side of 

 the larynx, a very fine branch that quickly divides into two ramuscules, one 

 of which joins the great hypoglossal nerve, and the other goes to the thyro- 

 hyoid muscle. It then throws off, from its convex side, several small descend- 

 ing nerves, all of which are destined to the subscapalo-hyoi^, sterno-hyoid, 

 and thyroid muscles. 



One of these filaments, joined by a ramuscule from the second pair, is 

 distinguished for its great length ; it may be followed to near the sternum, 

 where it is expended in the fleshy mass common to the four muscles that 

 extend from that bone to the larynx and os hyoides. Its constant disposition 

 should obtain for it the name oi precervical nerve. 



Second. — This descends beneath the great oblique muscle (obliquus 

 posticus ), crossing the direction of the rectus anticus major, and ramifying 

 therein by numerous branches. "We specially indicate : 1, Those furnisbed 

 to the latter muscle, and which are the shortest and deepest ; 2, The atloid 

 loop, a long, thick superficial branch, which enters the anterior portion of 

 the levator humeri, and is directed forward and upward on the parotid 

 gland, bending round the transverse process of the atlas : this ramuscule 

 gives off filaments to the parotido-auricularis, as well as to the subcutaneous 

 muscle of the face, and terminates in two branches of unequal volume, the 

 largest of which ascends on the outer side of the concha, and the other, 

 situated behind, reaches the cervico-auricular muscles ; 3, Another superficial 



