10 Muscles of Head ana Neck 



ery 

 us. 



i 



cross the floor of the triangle upon the first rib. and above the artery 

 the trunks of the cervical nerves slant down for the brachial plexus. 

 In front of the artery is the scalenus anticus, and behind the nerves 

 the scalenus medius. Some lymphatic glands lie in the space ; th 

 are apt to be enlarged in malignant disease of the mamma, ccsophag 

 and also of thestomach. 



The anterior triangle is crossed obliquely by the anterior belly of 

 the omo-hyoid and by the posterior belly of the digastric, and is thus 

 divided into three triangles, which are named, from above downwards, 

 the submaxillary, and the superior and the inferior carotid triangles. 



The submaxillary triangle is bounded above by the lower border 

 of the jaw, and by aline drawn from its angle to the mastoid process 

 below by the posterior belly of the digastric and the stylo-hyoid ; a: 

 in front by the median line of the neck. 



It is covered by a skin, superficial fascia, platysma, and deep fasci 

 together with branches of the infra-maxillary (p. 67) and superfici 

 cervical nerves. Its floor is formed by the hyo-glossus, mylo-hyoi 

 and anterior belly of digastric. 



The space contains the submaxillary gland, with the facial artery a 

 vein (p. 29) ; the mylo-hyoid nerve and artery, and the submen 

 branch of the facial artery. Behind the submaxillary gland is t 

 stylo-maxillary ligament, immediately behind which is the parot 

 gland. (For the anatomy of the parotid region see page 117.) 



The superior carotid triangle is bounded behind by the stern 

 mastoid, above by the posterior belly of the digastric, and below by 

 the anterior belly of the omo-hyoid. It is covered by skin, superficial 

 fascia, platysma, and deep fascia, and is crossed by branches of the 

 superficial cervical and infra-maxillary nerves. Its floor is formed by the 

 thyro-hyoid and hyo-glossus, by the lower constrictors of the pharynx, 

 and by the upper part of the thyroid cartilage. It takes its name from 

 the fact that it contains the upper part of the common carotid and the 

 beginning of the external and internal carotids. In the triangle the 

 external carotid gives off the superior thyroid, lingual, facial, ascending 

 pharyngeal, and occipital branches. Corresponding venous tributaries 

 join the internal jugular, which, together with the vagus, is in the 

 carotid sheath. Additional contents of the space are the hypo-gloss 

 descendens and communicantes noni, and the superior laryngeal nerve 

 and a small piece of the spinal accessory nerve may be seen in t 

 highest angle, and of the recurrent laryngeal in the lowest angle, of t 

 space The sympathetic cord is behind the carotid sheath. 



The inferior carotid triangle contains the lower cervical part of t 

 common carotid. Its boundaries are the sterno-mastoid, the anteri 

 belly of the omo-hyoid, and the median line of the neck. It is cove 

 by skin, platysma, and fasciae, together with branches of the superfici 

 cervical nerve. 



As a matter of fact, the carotid artery is shut out of this triangle 



