Pe a >t 
NECK. 
ascends here ; and since, from the angle of the 
jaw to the base of the skull, it lies beside the 
pharynx, covered by the lateral parts of that 
cylinder, it is liable to be involved in a punc- 
tured wound from the mouth; and this unfor- 
tunate accident has not unfrequently occurred 
in operations on the tonsil, which organ in its 
swollen state is so closely applied to the in- 
ternal carotid artery, that if it were transfixed 
by a bistoury in an outward direction, the 
vessel could hardly escape. Hence the im- 
portance of care, in relieving tonsillary ab- 
Scesses, to direct the point of the instrument, 
as much as possible, towards the median line, 
and to select for incision that part of the cyst 
which most nearly adjoins the palate. The 
jugular vein emerges behind the artery and 
runs downwardly along its outer side: of the 
three divisions of the eighth nerve, which leave 
the cranium in front of the vein, the glosso- 
pharyngeal is applied to the outer, the vagus 
and spinal accessary to the inner part of its 
circumference. The muscular branch of the 
latter winds from within behind the vein, and 
obliquely descends to the sterno-mastoid : the 
Vagus continues to descend vertically along its 
inner side, but both the glosso-pharyngeal and 
hypo-glossal nerves obliquely cross between it 
and the artery, and subsequently arch over the 
latter in their passage to the tongue. From its 
Telations to the vertebre in this space, the pha- 
Iynx may participate in their diseased condi- 
tions, and give vent to abscesses, dependent on 
caries of the cervical spine. The surgeon may 
sometimes assist his diagnosis of complaints so 
Situated, by introducing his finger into the 
nx.* 
8. Lastly, I proceed to recapitulate, briefly 
and in connexion, the practical relations of the 
sterno-cleido-mastvideus in regard of the spaces 
which have been described. Its clavicular 
_ Origin is in the inferior division of the posterior 
triangle, covers the subclavian artery in the first 
and second portions of its course, and in many 
instances extends this origin so far outwardly 
as to hide the vessel during a considerable part 
of its third stage ; it likewise, of course, covers 
Many parts lying between it and the artery,— 
the jugular and subclavian veins, the vagus and 
phrenic nerves, the scalenus anticus and omo- 
yoid muscles, and the origin and divergence 
of many arterial branches: these fibres obviously 
Tequire division, varying according to circum- 
‘stances, when the subclavian artery is to be 
exposed. The interval between its origins cor- 
Tesponds to the sterno-clavicular joint, and, on 
the right side, to the bifurcation of the arteria 
imnominata : along the cellular line, prolonged 
from this interval, (which answers to the dia- 
eel dividing the two great triangles,) M. Se- 
lot proposes to penetrate, without section of 
* A case has lately occurred to the writer illus- 
trating this fact. It was one of neuralgia; the pain 
was of extreme severity and obstinacy ; it affected 
peorapical region, and was referred to the great 
occipital nerve. An examination through the 
pharynx succeeded in detecting, as its probable 
cause, a firm (apparently bony) tumour, connected 
with the transverse processes, between which that 
nerve emerges. 
583 
muscular fibre, in order to reach the common 
carotid artery. The sternal head of tue muscle, 
directing itself backward, obliquely crosses, in 
the inferior segment of the great anterior trian- 
gle, the sheath of the vessels, from which tbe 
sub-hyoid muscles partly divide it. In order 
to reach the common carotid artery these fibres 
are accordingly cut asunder, except where the 
operator prefers the anatomical finesse of M. Se- 
dillot’s plan. Tracing the muscle in the middle 
of the neck, we find it a most serviceable guide 
in operations on the common carotid, and on 
its primary or secondary branches. A vertical 
incision directed to the point of its intersection 
with the omo-hyoid muscle (nearly opposite the 
cricoid cartilage) enables the surgeon conve- 
niently to draw these muscles aside, and to 
expose, according as the wound is higher or 
lower, the external and internal carotids, or the 
trunk from which they originate, and, in close 
connexion with the anterior layer of theirsheath, 
the descending branch of the hypo-glossal. 
Finally, about and above the level of the hyoid 
bone, the anterior edge of the sterno-mastoid, 
with the posterior belly of the digastric, and 
the cornu of the os hyoides, furnish definite 
marks for discovering the superior thyroid, the 
lingual, the facial or the continued exterral 
carotid artery; since, in the space so bounded, 
the last named vessel vertically ascends, the 
first almost horizontally advances, and the other 
two pass to their destinations with intermediate 
obliquity. 
IV.—ADDITIONAL PRACTICAL OBSERVATIONS. 
It yet remains, in conclusion, briefly to 
review some circumstances in the anatomy of 
the neck, which particularly bear on its dis- 
eases and on the operations undertaken for 
their cure. 1. In endeavouring to form a 
diagnosis of tumours in this region, the surgeon 
will, in the first place, remember their extreme 
liability to deceptive pulsation, and will neg- 
lect no precaution for ascertaining their rela- 
tion to the large arterial trunks. The glands, 
which lie about the common and external ca- 
rotid arteries, in the anterior triangle of the 
neck, and those which are situated in the 
supra-clavicular space, are particularly subject, 
when enlarged, to derive pulsation from the 
vessels to which they are respectively conti- 
guous. The history of the case,—the signs 
afforded by auscultation,—the manner in which 
a non-aneurismal tumour may frequently be 
moved away from the artery that communi- 
cates an impulse to it,—the marked difference 
even to the unpractised hand, between the 
mere jerk of elevation in the one case, and the 
thrilling diastole in the other, are materials for 
distinction, to which it is here enough to allude. 
Nor must it be forgotten, that, from the near- 
ness of the aortic arch to the root of the neck, 
its aneurisms, as they grow upwards and clear 
the strait of the thorax, may simulate the cha- 
racters of a like disease in the carotid or sub- 
clavian artery. Cases constantly occur, (and 
may be found abundantly quoted in systematic 
surgical works,) in which tuinours of this kind, 
