NODES OF THE HEAD AND NECK 709 



II. SPECIAL ANATOMY OF THE LYMPHATIC SYSTEM 



The lymphatic system will be considered by regions as follows: A, head and 

 neck; B, upper extremity; C, thorax; D, abdomen and pelvis; E, lower ex- 

 tremity. 



A. THE LYMPHATICS OF THE HEAD AND NECK 



The lymphatics of the head and neck may be divided into two sets. One set is 

 superficial, draining the entire skin surface, and has its nodes, for the most part, 

 in the neck, the principal group lying along the external jugular vein. The other 

 set is deeper and drains the mucous membrane of the upper part of the digestive 

 and respiratory tracts, together with the deep organs, such as the thyreoid gland 

 and the tendons of the muscles. The nodes of this set are deeply placed, being 

 situated along the carotid arteries, with outlying retro-pharyngeal nodes. 



1. THE SUPERFICIAL NODES OF THE HEAD AND NECK 



Lymph-nodes appear first in the neck in the process of development. In the 

 pig the first node to appear develops from the lymph heart, which is in the supra- 

 clavicular triangle behind the sterno-cleido-mastoid muscle. From here ducts 

 grow across the muscle and give rise to a chain of nodes along the external jugular 

 vein. This chain is to be considered as the main chain of superficial nodes in the 

 neck. From it lymphatic vessels grow over the back of the head, the side of the 

 head, the face, and the front of the neck, and in their course groups of secondary 

 nodes develop. The nodes of the main chain are known as the superficial cervical 

 nodes, and are from four to six in number. The secondary groups are — (1) the 

 occipital; (2) the posterior auricular; (3) the anterior auricular; (4) the parotid; 

 (5) the submaxillary, with the facial as a tertiary set, and (6) the submental. 



1. The occipital nodes [lymphoglandulse occipitales]. — The lymphatics of the 

 skin of the back of the head collect into a few trunks that either empty into from 

 one to three small nodes near the occipital insertion of the semispinalis capitis 

 muscle, or pass by the secondary group and empty directly into the upper nodes 

 of the main superficial cervical chain (fig. 555). 



2. The posterior auricular nodes [Igl. auriculares posteriores]. — A portion of 

 the temporal part of the scalp, together with the posterior surface of the ear, except 

 the lobule, and the posterior surface of the external auditory meatus, drain into 

 two small nodes on the insertion of the sterno-cleido-mastoid muscle. The effer- 

 ent vessels of these nodes pass to the upper part of the superficial cervical chain. 



3. The anterior auricularnodes [Igl. auriculares anteriores] are few in number — 

 from one to three — and are situated immediately in front of the tragus of the ear. 

 They receive vessels from the anterior surface of the auricle and the external audi- 

 tory meatus, from the integument of the temporal region and the lateral portion 

 of the eyelids. Their efferents pass to the parotid and superior deep cervical 

 nodes. 



4. The parotid nodes. — The parotid group of nodes is considerably larger than 

 the two preceding, containing from ten to sixteen nodes, and the group drains a 

 more complex area. It receives vessels from the adjacent sm-face of the external 

 ear, the external auditory meatus, the skin of the temporal and frontal regions, 

 and the eyelids and nose. The deeper nodes of this set receive vessels from the 

 parotid gland. 



In the embryo these nodes he in the pathway of the lymph- vessels that grow to the scalp; 

 many of these vessels, however, pass the parotid group and empty into the superficial cervical 

 chain. The nodes of the parotid group he embedded in the substance of the parotid gland, 

 and their efferents pass to the submaxillary and the superior superficial and deep cervical nodes. 



As "inferior auricular nodes" Bartels designates one or two small glands of the parotid 

 group which lie below the ear, and receive afferent vessels from the lower part of the ear. 



5. The submaxillary [Igl. submaxillares] and facial [Igl. faciales profundse] 

 nodes. — The submaxillary (perhaps better "mandibular") group consists of a 



