ANATOMY. 
ducts of the above-mentioned glands, which 
discharges a fluid when pressed ; anti being 
examined through a microscope, they appear 
; vascular or folliculous, much like that of the 
stomach. 
The ligaments between the cartilaginous 
circles are very strong and elastic, and each 
of them is confined to two cartilages, without 
communicating with any of the rest ; being 
fixed to the edges of these cartilages much in 
f tiie same manner as the intercostal muscles 
| are inserted in the ribs. 
As the bronchia penetrate into the substance 
1 of the lungs, they gradually lose their carti- 
j lages, till at last they become purely mem- 
1 branous; but the muscular lines of M. Mor- 
gagni appear as much, and sometimes more 
than before. The two planes above-men- 
' tioned continue likewise to be visible; and 
: we observe very distinctly sometimes, even 
| without a microscope, a great many small 
! holes in the pellicles of the lobuli, and bron- 
! chial vesicles or cells, which open from within 
| outward. 
Of the arteries in general. 
. The arteries are long elastic and pul- 
j sating tubes, the diameters of which decrease 
j according to the number of branches which 
they give oft’. 
The coats of the arteries are three in num- 
ber : an external or cellular coat, a middle 
or muscular coat, and an internal or smooth 
I membranous coat. 
The use of the arteries is to convey blood 
i from the heart through the lungs, throughout 
! the system in general, or the heart itself. 
'The origin of the two great trunks from 
j which they all arise has already been ex- 
plained, and of these two all the rest are 
branches. 
OF PARTICULAR ARTERIES. 
The aorta. 
The large arteries, termed aorta, open with 
a wide orifice from the superior and posterior 
side of the left ventric le of the heart. Its 
I roots seem incorporated with the very sub- 
J stance of the heart; as it is not only inti- 
mately united with its internal surface, hut 
some muscular striae of the ventricle are also 
mixed with the white line, which is called 
' tehdo-arteriosus, and which indicates the com- 
mencement of the artery. Some transverse fi- 
bres of the heart are united to the external part 
of the aorta, and cover it for a line and a half. 
Having left the heart, the aorta is immedi- 
ately expanded ; nor does it again recover its 
diameter till it sends off the subclavian artery 
of the right side. 
In its ascent, it is first inflected to the right, 
behind and beyond the pulmonary artery ; 
it gradually inclines itself to the left, till, having 
formed a transverse arch, it is seen projecting 
behind the lungs at the left side of the verte- 
bra?. Supported by these it descends in the 
same straight line with themselves : till hav- 
ing, at last, entered the abdomen, it again 
begins to turn toward the right, and rests 
/upon the middle of the vertebra?. 
By the arch of the aorta is meant its para- 
bolic flexure, the right pillar of which first 
stretches to the right, and then to the left, 
while the left advances almost in a straight 
line. 
In considering the whole extent of the arch, 
we observe that it springs from the ventricle at 
the inferior margin of the third rib, ascends by 
an oblique and winding course to the lower 
margin of the first ; its exterior and right ex- 
tremity corresponding to the middle of the 
cartilages of the ribs; and its left extremity, 
being concealed by tthe left lobe of the lungs, 
proceeding onward, and in like manner cor- 
responding to the vertebral extremity of the 
ribs. 
FIRST SUBDIVISION. 
Branches from the arch of the aorta. 
I. The two coronary arteries of the heart, 
viz. the right or inferior, and left or superior, 
which being sent off’ above the interior and 
posterior semilunar valves, form, in returning 
to the heart, an acute angle with the rising 
trunk. II. The innorrtinata. III. The left 
common carotid. IV. The left subclavian. 
The three last arise at distinct branches 
from the greatest convexity of the arch. The 
first of them passes obliquely upward, and to 
the right over the trachea ; and having ad- 
vanced about two inches, divides at its right 
extremity into the right common carotid, 
and the right subclavian. The other two 
branch out from the aorta near the former, 
and are also similar to them. 
I. The right coronary is larger than the 
left. Covered with fat, it runs between the 
auricle and ventricle to the flat surface and 
apex of the heart, inosculating freely with the 
left coronary, both by its branches, and the 
extremity of its trunk. 
II. The left coronary, after going out 
between the pulmonary artery and left auri- 
cle, divides into two branches. 
III. The right subclavian. For the descrip- 
tion of this and the left one, see below. 
IV. The common carotid has on each side 
a similar distribution of its branches, though 
the right be a little larger than the left. It 
lies on the anterior surface of the vertebra*, 
and is united by a cellular membrane to the 
intercostal nerve, the par vagum beneath, 
and the internal jugular vein above. It thus 
ascends one continued trunk parallel to the 
trachea, as high as the superior margin of the 
thyroid cartilage. It there divides into 
branches of equal size ; the anterior of which 
is called the external, and the posterior the in- 
ternal or cerebral. 
Distribution of the common carotid. 
(T.) The external or superficial carotid. — 
This artery has scarcely arisen, when it ad- 
vances forward, and divides into eight 
branches variously distributed. 
1 . The superior thyroid, issuing near 
the origin of the trunk, and descending 
windingly to the superior margin of the 
thyroid gland. 
2. The lingual or sublingual arterv, 
winding above the os hyoides, forward, 
upwards, and inwards, to the tongue. 
At its commencement, it either passes 
over, or is covered by, the hyo-glossus ; 
then is concealed by the genioglossus. 
3. The internal maxillary, labial, an- 
gular, or facial. Concealed at its origin 
by the stylohyoideus, and the tendon 
of the digastric. Ascends tortuously 
forward, through the depression of the 
sub-maxillary gland, and, winding over 
the maxilla, follows the anterior margin 
of the masseter ; afterward branches out 
M 2 
III 
under the zygomatic muscle?, in serpen- 
tine windings, upon the face and the 
sides of the mouth and of the nose. 
4. The ascending pharyngeal of Hal- 
ler arises from the back part of the trunk, 
near the lingual, or from the bifurcation 
of the carotid. The auricular except- 
ed, it is the smallest of the branches. It 
ascends upon the long anterior reclu* 
muscle to the foramen lacerum, through 
which it passes, to be lost in the dura 
mater. 
5. Occipital artery passes transversely 
before the jugular vein, above the rectus 
lateralis, proceeding between the trans- 
verse process of the atlas and mastoid 
process to the back part of the neck, and 
ascends, in widely-spreading branches, 
to the occiput. In its course it is co- 
vered by the diagastric, the trachelo- 
mastoid, the splenius, and the corn- 
plexus ; and becomes subcutaneous as it 
approaches the occiput. 
6. The posterior auricular or stylo- 
mastoid, rises from the trunk in the pa- 
rotid gland, above the digastric muscle, 
and before the styloid process, then 
passes transversely to the ear. As it 
curves behind the ear, it also inclines to 
the posterior part of the squamous bone, 
inosculating with the temporal and occi- 
pital arteries. 
7. The superficial temporal. This 
• artery, concealed at first in the parotid 
gland, stretches above the zygomatic 
arch, between the jaw' and meatus audi- 
tories, and is at last extensively ramified, 
over the side of the head. 
8. Internal maxillary. This artery, 
larger than the temporal, rises about the 
middle of the ramus of the inferior max- 
illary bone, before the external ptery- 
goid ; and, bending inward, forward, 
and downward, is concealed by the max- 
illa. It then rises obliquely upward and 
forward to the spheno-m axillary fissure. 
(II.) The internal carotid or cerebral ar- 
tery. — This artery, in rising to its canal, is 
connected before to the par vagum and inter- 
costal nerves ; and behind to the rectus an- 
ticus muscle. Sometimes it forms above the 
vertebra? a larger or smaller projecting curva- 
ture. In this course no branches are, in ge- 
neral, given off. At last it enters the fora- 
men carotideum ; and passing along this ca- 
nal, undergoes many remarkable inflections. 
On its first entering the foramen, it proceeds 
upward, inward, and a little forward. It 
then rises from the canal forward and 
upward at a very obtuse angle. Having 
at last reached the posterior part of the sella 
Turcica, it bends in the cavernous sinus, so as 
to run in an horizontal direction to the ante- 
rior clinoid process. It here rises perpendi- 
cularly, perforates the internal surface of the 
dura mater, and proceeds near the bottom of 
the brain backward to the cerebrum. 
Its most remarkable branches are, 
. 1 • The ophthalmic artery, rising in the 
angle where the carotid artery leaves the 
sphenoid bones near its anterior clinoid 
processes, and running with the nerve, 
which accompanies and rests upon it, 
through the optic hole, to the orbit! 
Lying by the external side of the optic 
nerve, It passes obliquely forward over 
it; and reaching the internal angle 
