THE LYMPH GLANDS AND VESSELS OF THE HEAD AND NECK 699 
anterior part of the tongue, the jaws, the floor of the mouth, and the greater part 
of the hard palate and nasal cavity. The efferent vessels pass to the anterior 
cervical and pharyngeal glands. 
Most of the superficial lymph vessels of the face converge to twelve to fifteen trunks which 
turn around the lower border of the jaw with and in front of the facial vessels. Those of the lips 
form plexuses at the commissures. The nasal mucous membrane is richly supplied with lymph 
vessels which accompany the veins; posteriorly they communicate with the subdural and sub- 
arachnoid spaces and send efferents to the pharyngeal and anterior cervical glands. 
2. The pharyngeal lymph glands (Figs. 562, 706) usually comprise two 
groups. One lies on the upper part of the lateral surface of the pharynx, along the 
course of the external carotid artery. These glands are related laterally to the 
occipito-mandibularis and digastricus, and often to the mandibular gland also, 
above to the guttural pouch; they may properly be termed the parapharyngeal 
lymph glands (Lgg. parapharyngeales). Other small glands are commonly found 
on the guttural pouch along the course of the internal carotid artery; they are best 
designated as the suprapharyngeal lymph glands (Lgg. suprapharyngeales).! They 
lie below the artery and are covered by the aponeurosis of the brachiocephalicus 
and the cervical end of the mandibular gland. In some cases a number of glands 
occur in the angle of divergence of the external and internal carotid arteries. 
They receive afferent vessels from the cranium, the posterior part of the tongue, 
the soft palate, pharynx, guttural pouch, larynx, posterior part of the nasal cavity, 
and efferents from the mandibular glands. 
3. The anterior cervical lymph glands (Lge. cervicales craniales) (Fig. 646) are 
situated along the course of the common carotid artery, in the vicinity of the thyroid 
gland, under cover of the cervical angle of the parotid gland. Some occur between 
the thyroid and the mandibular salivary gland, others above and partly upon the 
thyroid. They are related deeply to the posterior part of the larynx, the trachea, 
the thyroid gland, and the esophagus; below to the external maxillary vein and 
the lateral border of the omo-hyoideus.” 
These glands are variable. Often there are none in front of the thyroid and the group may 
extend back a considerable distance along the course of the carotid artery. 
Their afferents are deep lymph vessels from the head, the pharynx, larynx, 
guttural pouch, and thyroid gland, and efferents from the mandibular and pharyn- 
geal glands. Their efferent vessels go to the middle and posterior cervical glands. 
4. The middle cervical lymph glands (Lgg. cervicales medi) form an incon- 
stant group situated a littie in front of the middle of the neck on the trachea below 
the carotid artery. The group is usually small, and in some cases is replaced by a 
number of glands occurring at intervals along the course of the carotid artery. In 
other subjects the group consists of several glands of considerable size. They are 
intercalated in the course of the tracheal lymph ducts. 
5. The posterior cervical or prepectoral lymph glands (Legg. cervicales caudales) 
form a large group below the trachea at the entrance to the thorax (Fig. 590). 
They occupy the interstices between the vessels and muscles and extend forward a 
variable distance on the ventral aspect of the trachea. Posteriorly they are con- 
tinuous with the anterior mediastinal glands. They are covered by the cutaneus 
and sterno-cephalicus. Their afferent vessels come from the head, neck, thorax, 
and thoracic limb. They receive efferent ducts of the anterior and middle cervical, 
prescapular, and axillary glands. Their efferents go to the thoracic duct on the 
left, to the right lymphatic duct on the right, or open directly into the vena cava. 
6. The prescapular or superficial cervical lymph glands (Lgg. cervicales 
1 Much confusion exists in the terminology used in regard to these glands and the next group. 
The terms here recommended appear to the author to be the best, all things considered. The 
pharyngeal and anterior cervical glands are all subparotid in the horse. 
? Abscess here can be reached readily by an incision between the vein and the omo-hyoideus. 
