ANGIOLOGY 





In front of the sheath are a few descending filaments from the ansa hypoglossi; 

 behind the sheath are the inferior thyroid artery, the recurrent nerve, and the sym- 

 pathetic trunk; and on its medial side, the esophagus, the trachea, the thyroid 

 gland, and the lower part of the larynx. By cutting into the upper part of this 

 space, and slightly displacing the Sternocleidomastoideus, the common carotid 

 artery may be tied below the Omohyoideus. 



The Superior Carotid, or Carotid Triangle, is bounded, behind by the Sternocleido- 

 mastoideus; below, by the superior belly of the Omohyoideus; and above, by the 

 Stylohyoideus and the posterior belly of the Digastricus. It is covered by the integu- 

 ment, superficial fascia, Platysma and deep fascia; ramifying in which are branches 

 of the facial and cutaneous cervical nerves. Its floor is formed by parts of the Thyro- 

 hyoideus, Hyoglossus, and the Constrictores pharyngis medius and inferior. This 

 space when dissected is seen to contain the upper part of the common carotid 

 artery, which bifurcates opposite the upper border of the thyroid cartilage into the 

 external and internal carotid. These vessels are somewhat concealed from view 

 by the anterior margin of the Sternocleidomastoideus, which overlaps them. 

 The external and internal carotids lie side by side, the external being the more 

 anterior of the two. The following branches of the external carotid are also met 

 with in this space: the superior thyroid, running forward and downward; the 

 lingual, directly forward; the external maxillary, forward and upward; the occipital, 

 backward ; and the ascending pharyngeal, directly upward on the medial side of the 

 internal carotid. The veins met with are: the internal jugular, which lies on the 

 lateral side of the common and internal carotid arteries; and veins corresponding 

 to the above-mentioned branches of the external carotid viz., the superior thyroid, 

 the lingual, common facial, ascending pharyngeal, and sometimes the occipital 

 all of which end in the internal jugular. The nerves in this space are the following. 

 In front of the sheath of the common carotid is the ramus descendens hypoglossi. 

 The hypoglossal nerve crosses both the internal and external carotids above, 

 curving around the origin of the occipital artery. Within the sheath, between the 

 artery and vein, and behind both, is the vagus nerve; behind the sheath, the sym- 

 pathetic trunk. On the lateral side of the vessels, the accessory nerve runs for a 

 short distance before it pierces the Sternocleidomastoideus; and on the medial 

 side of the external carotid, just below the hyoid bone, may be seen the internal 

 branch of the superior laryngeal nerve; and, still more inferiorly, the external 

 branch of the same nerve. The upper portion of the larynx and lower portion of 

 the pharynx are also found in the front part of this space. 



The Submaxillary or Digastric Triangle corresponds to the region of the neck 

 immediately beneath the body of the mandible. It is bounded, above, by the lower 

 border of the body of the mandible, and a line drawn from its angle to the mastoid 

 process; below, by the posterior belly of the Digastricus and the Stylohyoideus; 

 , in front, by the anterior belly of the Digastricus. It is covered by the integument, 

 superficial fascia, Platysma, and deep fascia, ramifying in which are branches 

 of the facial nerve and ascending filaments of the cutaneous cervical nerve. Its 

 floor is formed by the Mylohyoideus, Hyoglossus, and Constrictor pharyngis 

 superior. It is divided into an anterior and a posterior part by the stylomandibular 

 ligament. The anterior part contains the submaxillary gland, superficial to which 

 is the anterior facial vein, while imbedded in the gland is the external maxillary 

 artery and its glandular branches; beneath the gland, on the surface of the Mylo- 

 hyoideus, are the submental artery and the mylohyoid artery and nerve. The 

 posterior part of this triangle contains the external carotid artery, ascending deeply 

 in the substance of the parotid gland ; this vessel lies here in front of, and super- 

 ficial to, the internal carotid, being crossed by the facial nerve, and gives off in 

 its course the posterior auricular, superficial temporal, and internal maxillary 

 branches: more deeply are the internal carotid, the internal jugular vein, and the 



