THE LYMPHATICS OF THE NECK. 959 



line between the two crico-thyroid muscles, another descends over the isthmus of 

 the thyroid gland to terminate in one of the nodes which rest upon the anterior 

 surface of the trachea, while one or two pass outward along the upper border 

 of the lobes of the thyroid gland and then descend to terminate in one of the 

 superior deep cervical nodes situated about opposite the middle of the sterno-cleido- 

 mastoid muscle. The posterior stems, which are from three to six in number, after 

 making their exit from the larynx, follow the course of the recurrent laryngeal 

 nerves and terminate in the recurrential nodes situated in the course of those nerves, 

 some of the stems frequently anastomosing to form a plexus which descends along 

 the vagus nerve and may be followed, in some cases, to the inferior deep cervical 

 nodes. 



The net-work of the trachea is formed of delicate and slender vessels arranged so 

 as to form elongated meshes, and the stems which arise from it emerge from the 

 lateral surfaces of the trachea, passing between the tracheal cartilages. Those from 

 the upper part of the trachea pass to the recurrential nodes, while the lower ones 

 pass to the bronchial nodes situated in the neighborhood of the bifurcation of the 

 trachea. 



The Thyroid Gland. — The lymphatic stems from the thyroid gland pass for 

 the most part to the superior deep cervical nodes, following the course of the superior 

 thyroid artery, some of them, however, passing at first directly upward and coming 

 into relation with an anterior cervical node situated upon the crico-thyroid 

 membrane. Those which arise from the lower border of the isthmus and from the 

 neighboring portions of the lobes are directed downward, and terminate in the 

 anterior cervical nodes which are situated upon the anterior surface of the trachea 

 and in the recurrential nodes. 



The CEsophagus. — The cervical portion of the oesophagus will be considered 

 together with its thoracic portion (page 971). 



Practical Considerations. — The Lymph- Nodes of the Neck. — i. TV^ super- 

 ficial cervical nodes — not invariably present — are found over the sterno-mastoid, 

 along the external jugular vein, between the deep fascia and the platysma, and may 

 be enlarged in various affections of the external ear and of the skin of the face and 

 neck, or consecutively to infections of the suboccipital (occipital), mastoid (post- 

 auricular), parotid (preauricular), or submaxillary nodes. Those found posteriorly 

 near the anterior border of the trapezius muscle enlarge early in the secondary stage 

 of syphilis and, on account of their accessibility for palpation, are then of diagnostic 

 value. 2. The d'f?!?/* ^^r27Va/;z6>^^.y are divisible, for convenience, into two groups : (a) 

 an upper group, situated about and above the bifurcation of the common carotid artery 

 and the upper part of the internal jugular vein, some of which lie partly beneath the 

 posterior edge of the sterno-mastoid and partly projecting into the posterior cervical 

 triangle ; (^b) a lower group, found near the lower portions of the internal jugular, 

 external jugular, subclavian, and transverse cervical veins, and lying almost com- 

 pletely beneath the sterno-mastoid. At the root of the neck this group is continuous 

 externally with the subclavian and axillary, and internally with the mediastinal nodes. 

 All these deep cervical nodes lie in or beneath the deep fascia and receive the 

 efferent vessels from the superficial nodes (and thus from their tributaries mentioned 

 above) as well as all other lymphatics of the head and neck — retropharyngeal, 

 suprahyoid, etc. — that do not directly communicate with the superficial group. 



The deep cervical nodes are accordingly found to be inflamed or enlarged 

 consecutively to a great variety of conditions, — e.g.^ eczema, wounds or ulcers of 

 any portion of the scalp or face, dental caries, alveolo-dental abscess, pharyngeal 

 or buccal or tonsillar inflammation or ulceration, fissures or ulcers or carcinoma 

 of the tongue, otitis (external or medial), rhinitis, hordeolum, labial herpes or 

 chancre or epithelioma. They may also be enlarged — though with great rarity — 

 from primary carcinoma and — less rarely — from lympho-sarcoma or from Hodgkin's 

 disease. Furthermore, various intracranial conditions may be followed by involve- 

 ment of the cervical nodes, both superficial and deep. In most cases the infection 

 comes from the same side of the head, face, or neck, as the enlarged glands, but 

 occasionall)'- the original lesion is on the opposite side. 



