DISSECTION OF THE HEAD AND NECK. 175 



being related inwardly to the insertion of the subscapulo-hyoid muscle, 

 and outwardly to the submaxillary artery. The right and left groups 

 extend towards each other, and nearly meet below the extremity of 

 the glossal (spur) process of the hyoid bone. These glands are placed 

 on the track of the lymphatic vessels coming from the mouth and 

 nose ; and in morbid states of these parts, such as glanders, the 

 glands become inflamed and enlarged from the irritant matters con- 

 veyed in the lymphatic vessels. They should be carefully excised to 

 expose the submaxillary artery and the inferior belly of the digastricus 

 muscle. 



The Submaxillary or Facial Artery (Plate 27) appears at the 

 upper part of the space, descending between the subscapulo-hyoid and 

 internal pterygoid muscles. At this point the inferior extremity of 

 the submaxillary salivary gland lies internal to it. In passing obliquely 

 backwards and downwards it rests on the internal pterygoid muscle, 

 and is partly covered by the lymphatic glands, beneath which it 

 detaches its submental branch. It then comes into company with 

 the vein of the same name, and with Stenson's duct ; and the three 

 vessels turn round the edge of the ramus to reach the face, the 

 artery being below, the vein in the middle, and the duct superior. 

 Where the artery turns round the ramus it is very favourably placed 

 for taking the pulse, since it is a vessel of considerable size, is in an 

 easily accessible position, rests directly on the bone, and is almost 

 subcutaneous, only the thin panniculus intervening between it and 

 the skin. 



The Submental Artery crosses downwards beneath the inferior belly of 

 the digastricus, then along the surface of the mylo-hyoideus, which it 

 perforates a few inches above the symphysis. It will be followed to its 

 termination in the dissection of the mouth. 



The Submaxillary Vein (Plate 27) is in contact with the artery where 

 the vessels turn round the ramus ; but, as it passes backwards, it recedes 

 slightly from the artery, and follows the posterior border of the sub- 

 maxillary gland. It leaves the space above the angle of the jaw, and is 

 continued along the lower edge of the parotid to join the jugular. At the 

 lymphatic glands it receives the submental vein, a larger vessel than the 

 artery of the same name. 



Stenson's Duct (Plate 27), after crossing the sterno-maxillaris tendon, 

 passes into the space, at the posterior edge of the submaxillary salivary 

 gland. It passes downwards on the internal pterygoid muscle, placing 

 itself in contact with the submaxillary vein, in company with which and 

 the artery it turns round the bone to reach the face. It is here the most 

 superior of the three vessels ; and, from its being superficially placed 

 and resting on the bone, it is liable to be opened when a blow is delivered 

 over this region. 



