952 



HUMAN ANATOMY. 



Sub- 

 maxillary 

 nodes 



Sub- 

 mental 

 node 



The vessels from the submucous tissues of the Hps pass mainly to the submaxil- 

 lary nodes, two or three stems passing from the lower lip and one or two from the 

 upper. Those of the loiver lip pass downward and outward toward the facial artery 

 and follow its course into the submaxillary region, while those from the upper lip are 

 directed at first almost horizontally outward toward the facial vein, whose course 

 they follow toward their termination. No anastomoses occur between the submucous 

 vessels of the two sides in either lip. 



The subcutaneous vessels of the upper lip (Fig. 803) have a course similar to 

 that of the corresponding submucous stems, with which they may unite, and they 

 terminate principally in the submaxillary nodes, although communication may also be 

 made with one of the lower parotid nodes. The subcutaneous vessels of the lower lip 

 are from two to four in number, and pass principally to the submental nodes, from which 



efferents pass to the sub- 

 FiG. 803. maxillary and superior 



deep cervical nodes. A 

 noteworthy peculiarity of 

 these lower lip vessels, 

 which is in marked con- 

 trast with what obtains in 

 the submucous stems, is 

 that those of the right 

 and left halves of the lip 

 anastomose, so that an 

 injection may pass from 

 the vessels of the right 

 half into the left sub- 

 mental and submaxillary 

 nodes. 



The lymphatics of 

 the lower gzims form a 

 very rich net-work from 

 which from fourteen to 

 seventeen stems arise. 

 These empty into a single 

 large collecting stem on 

 either side, which passes 

 outward over the outer 

 surface of the mandible 

 and, opposite the last 

 molar tooth, dips down- 

 ward to terminate in 

 the submaxillary nodes. 

 Whether or not the pulp 

 of the teeth contains lymphatic capillaries is a disputed question. ^ All attempts to 

 inject them have failed, but it has been maintained that their existence has been 

 demonstrated by histological methods. Enlargement of the submaxillary nodes has 

 been observed to follow dental lesions, but this may be due to the involvement of the 

 tissues of the gums rather than to that of the tooth pulp. 



The Tongue. — The lymphatics of the tongue (Fig. 804) are divisible into two 

 groups according as they arise in the submucous tissue or in the musculature. The 

 submucous vessels take their origin from an exceedingly rich net-work which extends 

 throughout the entire surface of the tongue. It is especially close toward the tip, 

 the meshes becoming larger posteriorly, and that portion of it which lies posterior to 

 the circumvallate papillae is independent of that of the more anterior portions of the 

 tongue. The vessels of the muscular portion of the organ are much less extensively 

 developed and the efferent stems which pass from them early unite with those of 

 the submucous net-work. These latter are quite numerous and for purposes of 

 description may be arranged in four groups. 



* Internat. Monatsschrift f. Anat. u. Physiol., 1900. 



Deep 



cervical 



nodes 



Subcutaneous lymphatics of lips and superior deep cervical nodes, 

 new-born child. {Dorendorf.*) 



