THE LYMPHATICS OF THE HEAD. 955 



The lymphatics of the tonsil, which resemble those of the soft palate in their 

 abundance, pass with the stems from the basal region of the tongue to the superior 

 deep cervical nodes. 



Those of the pharynx are also abundant, especially above (Fig. 799). The 

 stems which arise from the roof and upper part pass principally to the retro- 

 pharyngeal nodes, although some reach the superior deep cervical nodes, directly by 

 following the course of the ganglionated cord. The stems which have their origin 

 in the lower part of the pharyngeal net-work pass downward toward the larynx 

 and unite with its vessels to be distributed to the superior deep cervical nodes as far 

 down as opposite the level of the second or third tracheal ring. 



Practical Considerations. — The Lymph-Nodes of the Head. — The lymphatics 

 of the scalp pass from the plexus of fine radicles on the vertex into the suboccipital 

 (occipital), mastoid (postauricular), parotid (^preauricular), and superficial cervical 

 nodes, and a few — from the frontal region — into the submaxillary node, into one or 

 the other of which infection may be carried from any portion of the scalp. 



The suboccipital nodes — one to three on each side — lie on a line drawn from the 

 junction of the upper and middle thirds of the ear to the inion and about two inches 

 external to that point. They are often enlarged as a result of wounds or irritation 

 of the occipital and postauricular portion of the scalp and — especially in neglected 

 children — as a consequence of eczema affecting the skin back of the ear. The close 

 relation of the node to the great occipital nerve, on which it usually lies, gives rise 

 to marked tenderness on pressure, the nerve being compressed between the node 

 and the bone. The source of infection of these nodes may be intracranial — e.g., 

 suppurative meningitis of the cerebellar fossa (Macewen). 



'Y'^^ posterior auricular or mastoid node, found directly over the mastoid insertion 

 of the sterno-cleido-mastoid, is likewise usually infected from the same scalp region. 

 It may also be invoh'ed alone or together with the suboctipital and deep cervical 

 nodes in localized tuberculous mastoiditis or even in tuberculous otitis media. 



The parotid nodes, lying both in and upon the gland, receive lymph from and 

 consequently may be infected by lesions of the scalp, the outer portion of the lids, 

 the orbit, the cheeks, the nasal fossae, the naso-pharynx, the external auditory 

 meatus, the tympanum, or the temporo-mandibular joint. Chronic enlargement of 

 these nodes, especially of the deeper ones in the substance of the gland and beneath 

 the parotid capsule, may lead to a mistaken diagnosis of parotid tumor. Suppura- 

 tive inflammation of these deeper nodes gives rise to a true parotid abscess, which, on 

 account of the resistance of the strong parotid fascia, will be under great tension. 

 Sloughing of the parotid tissue may occur. There will be shooting pains in the 

 head, neck, and ear, from pressure on the branches of the trigeminus accompanying 

 the facial, or on the auriculo-temporal and great auricular nerves. The contiguity of 

 the temporo-mandibular joint — into which the abscess may open — makes movement 

 of the lower jaw painful. The relative weakness of the capsule anteriorly and on its 

 inner aspect causes the pus to travel forward towards the cheek, or inward towards 

 the pharynx, following sometimes the pharyngeal process of the parotid and giving 

 rise to a retropharyngeal abscess. Gravity and the cervical process of the parotid 

 may conduct the pus into the neck. 



The lymphatics of the face empty, the superficial set — accompanying the facial 

 vein —into the parotid and submaxillary nodes ; the deep set, with some of those of 

 the orbit, palate, nasal fossae, and upper jaw, are said to end in the internal maxil- 

 lary nodes situated at the sides of the pharynx anteriorly. According to Leaf, these 

 are only exceptionally present. Their involvement in infections spreading from the 

 above regions may give rise to " latero-pharyngeal abscess," causing a swelling 

 externally behind the angle of the mandible, and an inward projection of the pharyn- 

 geal wall posterior to the tonsil. The' proximity of the internal carotid should be 

 remembered, and the fact that an aneurism of that vessel has been opened under the 

 impression that it was an abscess of this variety (page 747). 



Some lymphatics from the chin and the mid-portion of the lower lip empty into 

 the suprahyoid (submental) nodes lying on the mylo-hyoid between the two 

 aaterior bellies of the digastrics. Enlargement of these nodes may be distinguished 



