24 TOPOGRAPHICAL ANATOMY OF THE 



ramus (ramus ascendens) up the neck. This ramus will be found 

 on the deep face of the semispinalis capitis, that is, between this 

 muscle and the ligamentum nuchas and spinalis cervicis, and should 

 be traceable as far as the second cervical vertebra, where it anastomoses 

 with a branch of the occipital artery. Twigs from it join branches of 

 the vertebral artery. 



Ligamentum nuch^e. The powerful, yellow, elastic ligament of 

 the nape of the neck performs the function of assistant to the muscles 

 that raise the head, and is readily divided into two parts. (1) Pars 

 occipitalis} — A strong, cord -like band passes from the external 

 occipital protuberance and a shallow depression lateral thereto, to 

 the extremity of the spinous process of the fourth thoracic vertebra, 

 where, without any definite demarcation, it is directly continuous with 

 the supraspinal ligament of the thoracic region of the vertebral 

 column. With a reasonable amount of care, the dissector may satisfy 

 himself that this portion of the ligament consists of right and left 

 bands firmly joined together; the double character being most obvious 

 in the upper part of the neck. Be3^ond the fifth cervical vertebra 

 the two halves fuse more and more completely as they run towards 

 the thoracic attachment of the ligament. Here, that is, at the 

 " withers," lateral wing-like extensions of the ligament are produced 

 and cover the surface of the trapezius and rhomboid muscles. 



The dissector should notice that this part of the ligamentum 

 nuchas is separated from the skin from which the mane grows by 

 a quantity of dense, elastic, fibrous and fatty tissue. He should also 

 note the occurrence and extent of two synovial bursae that are of 

 importance because of their possible involvement in pathological 

 processes. One of them occurs between the ligament and the 

 atlas;- the other, of variable size, lies between the ligament and the 

 extremity of the third (possibly also the second and fourth) thoracic 

 spinous process. Occasionally a third bursa may be found over the 

 spinous process of the second cervical vertebra. 



(2) Pars cervicalis? — A double reticular sheet of elastic fibres 

 fills the triangular interval between the preceding part of the liga- 

 ment and the vertebral column. As their union is by loose tissue 

 only, the right antl left halves of the sheet are easily separated. The 

 sheet forming this part of the ligament is more complete in that 

 portion of it that is nearer the head. As the thorax is approached 

 the gaps in the network become larger, and the bundles of fibres 



1 Frequently termed the funicular pari of the ligament. 



^ The occurrence and degree of development of this bursa is not constant. 



^ The so-called lamellar part of the ligament. 



