958 HUMAN ANATOMY. 



occipital nodes, while in the more anterior nodes efferents from the retropharyn- 

 geal, parotid, submaxillary, submental, and superficial cervical nodes terminate. 



Belonging to the second class and terminating in the more posterior nodes are 

 (i) a vessel which descends directly from the occipital region of the scalp ; (2) some 

 stems from the posterior surface of the pinna ; and (3) stems from the upper part 

 of the back of the neck. To the more anterior nodes pass ( i ) the majority of the 

 stems descending from the tongue ; (2) stems from the nasal mucous membrane, 

 the palate, and the upper portions of the pharynx ; (3) stems from the cervical 

 portion of the oesophagus ; (4) the majority of the stems from the larynx and those 

 which come from the cervical portion of the trachea, and (5) the stems from the 

 thyroid gland. 



The efferents from the lower nodes of the plexus pass partly to the inferior deep 

 cervical nodes, and partly unite with the efierents of these to form the jugular trunk, 

 which is described below. 



The inferior deep cervical nodes (lymphoglandulae cervicales profundae 

 inferiores), also termed the supraclavicular 7iodcs, occupy the supraclavicular triangle 

 of the neck, resting upon the scalene muscles and upon the trunks of the brachial 

 plexus. They are fewer in number and, as a rule, smaller than the superior deep 

 cervical nodes. In addition to the afferents from the superior nodes they receive ( i ) 

 a stem which passes directly downward from the occipital region of the scalp along 

 the posterior border of the sterno-cleido-mastoid muscle ; (2) vessels from the 

 integument and muscles of the lower portion of the neck ; (3) vessels from the 

 integument of the upper portion of the pectoral region ; (4) occasionally some 

 vessels from the arm which follow the course of the cephalic vein ; (5) some efferents 

 from the brachial groups of the axillary nodes ; and (6) vessels which pass to the 

 lower nodes of the left, rarely the right, side from the liver, ascending in the 

 suspensory ligament of that organ, piercing the diaphragm, and following the course 

 of the internal mammary vessels upward through the thorax. 



Their efferents unite with some of those from the superior deep cervical nodes to 

 form a single stem, the jugular trunk (truncus jiigularis), which on the left side 

 opens into the arch of the thoracic duct and on the right unites with the subclavian 

 trunk to form the right lymphatic duct. Both the right and the left trunks, how- 

 ever, frequently open directly into the subclavian vein. 



The Lymphatic Vessels. 



The Integument and Muscles of the Neck. — The lymphatic stems arising 

 from the subcutaneous and muscular net-works of the neck open into the posterior 

 nodes of the superior deep cervical chain. 



The L-arynx and Trachea. — The lymphatic net-work of the larynx is very 

 well developed over the greater portion of the mucous membrane and is especially 

 rich in the regions of the false vocal cords and the ventricles. Over the true vocal 

 cords, however, it is very feebly developed, and the entire net-work may therefore be 

 regarded as consisting of two portions, one of which is situated above the level of the 

 true cords and the other below them. The two portions are not, it is true, perfectly 

 distinct, since they are connected by the feeble net-work of the true cords ; but it has 

 not been found possible to force an injection from one portion into the other and, 

 furthermore, each portion gives rise to a special set of efferent stems. 



The stems which arise from the upper net-work are from three to six in 

 number on each side, and make their exit from the larynx through the lateral 

 portions of the thyro-hyoid membrane, in close proximity to the superior laryngeal 

 artery (Fig. 806). They then pass outward to the anterior nodes of the superior 

 deep cervical chain, some opening into the nodes situated in the neighborhood 

 of the bifurcation of the common carotid artery, while others, bending downward, 

 terminate in lower nodes. 



The stems from the lower net- work pass in two directions ; a few small ones 

 perforate the crico-thyroid membrane near the median line, while the rest are directed 

 posteriorly and make their exit below the lower border of the cricoid cartilage. The 

 anterior stems pass partly to an anterior cervical node situated usually in the median 



