56 HEAD AND NECK 



and it supplies the skin of the medial and lower part of the 

 posterior portion of the scalp and the adjacent part of the skin 

 of the back of the neck. Trace it upwards to its termination, 

 and downwards to the point where it pierces the deep fascia 

 covering the trapezius. At a still lower level look for the medial 

 divisions of the posterior rami of the other cervical nerves. 

 They are variable in number and position, but those which are 

 present will be found piercing the deep fascia over the trapezius, 

 at a short distance from the median plane, and running down- 

 wards and laterally towards the posterior triangle. 



After the cutaneous nerves have been found remove the 

 remains of the superficial fascia and the deep fascia from the 

 surface of the trapezius. 



The Terminal Part of the Greater Occipital Nerve. The 



greater occipital nerve is the large medial division of the 

 posterior ramus of the second cervical nerve. It enters the 

 posterior part of the scalp, after piercing the upper part of the 

 trapezius and the deep fascia of the back of the neck, and it 

 ramifies in the superficial fascia of the scalp over the occipital 

 bone and the posterior part of the parietal bone. It is accom- 

 panied by the branches of the occipital artery, and it com- 

 municates with the great auricular and lesser occipital nerves. 



Arteria Occipitalis. After the occipital artery emerges 

 from between the trapezius and the sterno-mastoid, at the apex 

 of the posterior triangle, or pierces the upper part of the 

 trapezius, its terminal part pierces the deep fascia of the 

 back of the neck and enters the superficial fascia of the 

 posterior part of the scalp. It anastomoses with its fellow of 

 the opposite side, and with the posterior auricular and the 

 superficial temporal arteries. As a rule, it breaks up into two 

 main branches, a lateral and a medial. The medial branch 

 gives off cutaneous twigs and a meningeal branch, which passes 

 through the parietal foramen and anastomoses with a branch 

 of the middle meningeal artery. Through the same foramen, 

 passes an emissary vein which connects the occipital veins 

 with the superior sagittal (longitudinal) sinus. 



Musculus Trapezius. The trapezius and latissimus dorsi 

 constitute the first layer of the muscles of the back. Only 

 that part of the trapezius which lies above the level of the 

 seventh cervical spine belongs to the dissector of the head and 

 neck ; the lower part and the latissimus must be cleaned by 

 the dissector of the arm, but the dissector of the head should 

 take the opportunity to revise his knowledge of the whole 

 origin and insertion of the trapezius. It arises from the 

 medial third of the superior nuchal line of the occipital bone, 



