136 THE HEAD AND NECK 



and the rhomboids,, the phrenic nerve and the long thoracic 

 nerve (of Bell) which all lie behind the fascial sheet are 

 perfectly safe. When the glands are being dissected from under 

 the posterior belly of the omo-hyoid, haemorrhage may occur 

 from the enlarged branches of the transverse cervical artery 

 which supply them. 



The removal of the lower anterior group of lymph glands is 

 fully described on p. 141. 



When all the deep cervical lymph glands are involved, the large 

 inverted J -shaped incision (p. 134) may be utilised, or it may 

 be converted into an inverted U. This operation is greatly 

 simplified by dividing the sterno-mastoid transversely below 

 the level of the accessory nerve and turning the cut ends upwards 

 and downwards. The internal jugular vein and the accessory 

 nerve are satisfactorily exposed by this procedure. Behind the 

 prevertebral fascia, the ascending cervical artery, which is a 

 branch of the inferior thyreoid, runs upwards in front of the 

 scalenus anterior on the medial side of the phrenic nerve and 

 gives numerous branches to the deep cervical lymph glands. 



Posterior Aspect of Neck. This region of the neck is 

 exposed by the surgeon in the operation for the division of the 

 posterior rami (primary divisions) of the cervical nerves, a 

 proceeding which is called for in certain cases of Spasmodic 

 Torti-collis. A vertical incision is made from a point midway 

 between the mastoid process and the external occipital protuber- 

 ance downwards to the level of the superior border of the scapula. 

 The line of this incision overlies the posterior triangle of the 

 neck above and the trapezius below. After the skin and fasciae 

 have been incised and undercut on each side, the splenius is 

 exposed in the upper part of the wound and can be recognised 

 by the direction of its fibres, which run upwards and laterally. 

 In the lower part of the wound the splenius is covered over by 

 the trapezius. The latter muscle is cut through in the line of 

 the original incision and dissected off the surface of the lower 

 part of the splenius. The whole of the splenius is next divided 

 in the same line, and the two parts of the muscle are undermined 

 and retracted. The longissimus capitis (trachelo - mastoid), 

 which is a thin muscular sheet closely applied to the deep surface 

 of the splenius, is usually retracted along with the lateral part 

 of the muscle. When this is the case, the vertical fibres of the 

 semispinalis capitis (complexus) are completely exposed, with 

 the superficial branches of the ramus descendens of the occipital 



