THE NECK. 1181 
The sterno-mastoid muscle forms one of the most important superficial land- 
marks of the neck. The anterior border of the muscle, the more distinct of the 
— External angular process 
__“Zygoma 
—_Temporal artery 
——Facial nerve 
Apex of mastoid process™ Y___'T'ransverse process of atlas 
“im —__— Facial artery 
Hypoglossal nerve--—-— \ ef y Yy-——Submaxillary gland 
Anterior be tly of digastric 
—-Tip of greater cornu of hyoid bone 
___ Tip of superior cornu 
eae of thyroid cartilage 
~ Body of hyoid bone 
——~ Pomuim Adami 
Bifureation of common 
carotid artery 
Sterno-mastoid— 
Carotid tubercle 
Apex of lung ae : 
; j _— Cricoid cartilage 
Brachial plexus—__ 
: __—__—— isthmus of thyroid gland 
Subclavian artery-—_ 
Clavicular head of sterno-mastoid 
Ist part axillary artery 
Coracoid process ~~ ; 
_Sternal head of sterno-mastoid 
_ Bifurcation of 
innominate artery 
Acromio- 
clavicular joint 
~TInfra-clavicular fossa 
—__ Upper border of — 
manubrium stern 
Se 
Sores ~ 
Greater tuberosity | Lesser tuberosity of 
of humerus * humerus 
Bicipital groove 
Fic, 800.—LatreraL ASPEcT oF NECK. 
two, may be felt along its whole extent. Between the prominent sternal origin 
and the broad ribbon-like clavicular origin is a slight triangular depression which 
overlies the lower part of the internal jugular vein. 
Digastric Triangle—This triangle is subdivided into an anterior or sub- 
maxillary portion and a posterior or parotid portion by the stylo- maxillary liga- 
ment. In the anterior portion is the submaxillary gland, which extends from the 
posterior half of the lower border of the mandible to the great cornu of the hyoid 
bone. The facial vein ce downwards and backwards superficial to the gland, 
while the facial artery, imbedded in its deep surface, arches upwards under cover 
of the angle of the jaw, where, according to Merkel, it approaches the tonsil, being 
separated from it, however, by the superior constrictor of the pharynx. The 
lingual artery may he ligatured in the digastric triangle, where it les behind the 
hyo-glossus a little above the great cornu “of the hyoid bone; the superficial guides 
to the vessel are the lower border of the submaxillary gland, and the hypoglossal 
nerve and lingual vein, which lie upon the hyo- glossus, the latter being recognised 
by the vertical direction of its fibres. The floor of the digastric triangle i is formed, 
from before backwards, by the mylo-hyoid, hyo- elossus,. and superior constrictor 
of the pharynx. The iemnphieete glands of this space receive their lymphatics from 
the face and mouth, including the tongue and teeth. Primary suppurative cellu- 
litis of the connective tissue of this space 1s called angina Ludovier. 
Carotid Triangle-—The central landmark of this triangle is the great cornu of 
the hyoid bone, the tip of which, when the fascia is relaxed, may be readily felt 
immediately in front of the anterior border of the sterno-mastoid, at a point corre- 
sponding to the centre of a line drawn from the tip of the mastoid process to the 
pomum Adami. The deep cervical fascia holds the upper part of the sterno- 
mastoid forwards towards the angle of the jaw, so that, with the fascia undivided, 
the anterior border of the sterno-mastoid overlaps the internal jugular vein and 
the bifurcation of the common carotid artery. ; 
