NECK. 
which spring from the external one, viz. the 
occipital passing obliquely toward the mastoid 
_ process, under cover of the posterior belly of 
_ the digastric, and hooked round by the hypo- 
_ glossal nerve; the muscular, which is not in- 
variably present, inclining outward to the 
P sterno-mastoideus; the lingual and facial (di- 
vided by an imaginary prolongation of the 
cornu of the os hyoides from the superior thy- 
roid) entering the digastric space, the former 
transversely by running along the cornu of 
_ the os hyoides between the hyo-glossus and 
middle constrictor, the latter more obliquely 
ascending; and the pharyngeal artery deeply 
‘unning upward beside the pharynx. To 
all these riches a more particular descrip- 
tion has been given in a previous article, 
‘than would be suitable to the present one; 
ind to that the reader is referred for the 
ails of their distribution. (See Carorip.) 
é jugular vein descends externally to the in- 
al, as to the common carotid, the vagus 
ing, as in the lower region of the neck, be- 
een the two vessels and rather behind them. 
® vein receives several branches, in travers- 
g this triangle, from the larynx and tongue, 
d usually the facial vein: all these, since 
come from within, must cross in front of 
‘artery, and sometimes form an intricate 
*xus, which much embarrasses an operator. 
front of the sheath descends, with a slight 
rd obliquity, the branch of the lingual 
®, which at the lower part of the space, 
md while lying over the vein, forms a reversed 
rch of communication with the cervical plexus, 
Whence branches are distributed to the sub- 
hyoid muscles. The integuments and pla- 
: Bi ens require no particular notice ; their veins 
_ and nerves have already been described ; 
_ among the former must be reckoned the an- 
i. jugular; the space contains a great num- 
of lymphatic glands, a long chain of which 
le concatenate) lies along the outer 
e of the sheath of the vessels, while some 
_ also lie about the thyroid and lingual arteries 
_ on the inner side of the sheath. The surgical 
a of this space are chiefly confined to 
ie arteries: ligature of the common carotid 
or of either of its branches may easily be per- 
formed here, since the vessels lie under a much 
less thickness and variety of parts than below. 
A vertical incision falling on the point of inter- 
section of the omo-hyoid and sterno-mastoid 
muscles, and successively dividing the super- 
ficial fascia (in which the platysma and cuta- 
neous nerves are contained) and the cervical 
aponeurosis (a single layer, as it stretches 
across the space, but, of course, double where 
it encloses the sterno-mastoid,) exposes the 
sheath of the vessels, the veins which trans- 
versely cross its arterial portion, and the de- 
scendens noni which runs on the part of its 
wall corresponding to the jugular vein: and 
here, as he might open the sheath lower or 
higher, the surgeon would expose the common 
carotid or its branches; and, in remembering 
that the internal (so named from its distri- 
bution only) lies at first external to and behind 
the other, he would be able to isolate and 
VOL. IIT. 
el 
577 
secure either of these at his option. In any 
attempt to tie the branches of (re external 
carotid, a clear notion of their respective re- 
lations to the hyoid bone is of indispensable 
necessity; and, in ascending toward the di- 
gastricus, it must be remembered that the 
lingual nerve crosses the carotid sheath but 
just below the border of that muscle, and that 
it and the facial vein are consequently exposed 
to injury. Attempts at suicide by cutting the 
throat seldom succeed; the incision is usually 
made closely either above or below the hyoid 
bone; in the former case entering the digastric 
regions, and dividing, with the muscles of the 
tongue, the lingual and perhaps the facial 
artery; in the latter case, traversing the thyro- 
hyoid membrane, penetrating the pharynx, per- 
haps implicating the epiglottis, dividing the 
thyroid artery, and very rarely reaching the 
external carotid. The mode of searching for 
these vessels must vary according to circum- 
stances, but, in all essential particulars, may 
readily be deduced from their anatomy. 
4. The postero-superior triangle is a large 
space of singularly little interest, having its 
inferior boundary fixed by the omo-hyoid mus- 
cle, its anterior by the diagonal which inter- 
sects this, its posterior by the edge of the trape- 
zius, and its apex by the mastoid process. It 
contains, below, a part of the brachial plexus 
(the anterior branches, namely, of the fifth and 
sixth cervical nerves, which directly pass be- 
neath the omo-hyoid muscle into the adjoining 
inferior triangle,) the whole of the cervical 
plexus and many of its branches, the spinal 
accessory nerve, obliquely crossing from the 
sterno-mastoid to the trapezius, which it enters 
near its clavicular insertion, and some rami- 
fications from the arteria transversalis colli, 
which, under the name of superficial cervical, 
ascend in the space, supply its cellular mem- 
brane and lymphatic glands, and ultimately 
inosculate with descending twigs from the 
occipital. The pre-vertebral fascia covers its 
deep parts; the common cervical extends be- 
tween its borders; the platysma myoides exists 
as a covering for it only in its lower part. 
5. The postero-inferior triangle, (that of the 
subclavian artery,) is one of manifold impor- 
tance. The well-known lines of the omo-hyoid 
and clavicle limit its area above and below, 
the former dividing it from the space last con- 
sidered, the latter from the pectoral region ; 
intersecting the omo-hyoid, our imaginary di- 
agonal, as it stretches from the centre of the 
sterno-clavicular joint upward and outward, 
bounds it internally, and constitutes an arbitrary 
but most useful separation between the space, 
exclusively appropriated to the subclavian artery 
with its branches and that internally adjoining 
it, (the antero-inferior,) which is the proper ter- 
ritory of the carotid. The parts forming its 
deep or posterior wall are, the transverse pro- 
cesses of the lower cervical vertebra and head 
of the first rib, the outer edge of the longus 
colli and the broad lower part of the scalenus 
posticus: its inferior wall presents the upper 
surface of the first rib, and within the curve 
of this bone a part of the upper inlet of the 
2 P 
