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moistens and prevents the adhesion of the heart to the pericardium. (b) This fluid is sometimes found to exist in considerable quantity, to the amount of several ounces; but so large a quantity has been considered as the effect of disease ; and it is a question, about which there have been many disputes, whether any perceptible quantity of the liquor pericardii exists during life, and in the state of health; and the better opinion seems to be that, in health only, a very small quantity can be detected, because as fast as it is discharged by one set of vessels, it is, in general, absorbed by another. But when in disease, these actions do not correspond, and

CHAP. V. Sect. I. CIRculation.

when either the discharge is too rapid, or the removal too slow, an accu

mulation may take place. (c)
The heart may be subject to malformation or malconformation, such as
the foramen in the septum of the auricles remaining open after birth,
and allowing a part of the venous blood of the right to enter the left
auricle, and pass off into the general circulation unoxygenized. So the
heart is liable to diseases, preventing the due oxydation of the blood,
besides others which may affect the frame in general. (e) These are
scarcely remediable, but though the art of medicine may be unavailing,
yet it will be important to observe paliatives and preventives of conse-
quences, and, in particular, perfect tranquillity, a light diet, and atten-
tion to the state of the bowels. (f) Malformations may be in the
pulmonary artery, so as to prevent the blood from freely passing from the
right auricle into the lungs, and being there renovated; (g) or the aorta
may be improperly placed; (h) or, instead of two hearts, there may be a
third, and each imperfect. In these cases life, in general, is very short
and painful, subject to great difficulty in breathing, palpitation, fits,
and sudden death. (i) Of these descriptions is the disease called
Cyania, or blue skin, where the skin is more or less blue, the lips purple,
with a general hebetude and inactivity, which is produced o by a
connate congenital communication of the two ventricles of the heart,
and, consequently, an imperfect discharge of the carbon of the blood in
the lungs, which constitute the proper organ of its elimination. (j) The
heart, also, may be too small for the system to which it belongs, or too
large. So the muscular walls of the heart are liable to increase, or dimi-
nution of their ordinary thickness. Without any apparent traceable
cause, the walls of the ventricles, and, occasionally, of the auricles,
increase in thickness and in the firmness of their texture, and the whole
heart acquires a magnitude nearly double that of its original and healthy
condition. This increase of thickness, to which the left ventricle is more
subject than the right, may be attended with dilatation of the cavity, or
otherwise. When it is accompanied with dilatation of the cavity, it is now
technically called “active aneurism” of the heart. Its occasional cause

(b) 1 Bost. 363; 1 Bell's Anat. 489; izars, part ii. p. 1, 2, 146, 147; 3 Good, 473; Quain's El. 575; 3 Paris & Fomb. 56. (c) 1. Bost. 363, 364. (d) As to the effect of anger, &c., 4 Good, 121; and as to palpitation, see 4 Good, 449; and as to the diseases of the heart in general see Dr. Hope on Diseases of the Heart and Great Wessels; and see 2 Bell, 76 to 84; Forsyth, 41, 44; 2 Par. & Fonb. 178; Liz. 146, 147; A. Burn on Diseases of the Heart; Abercrombie's contributions to the Pathology of the Heart, Trans. 1824; Dr. Laennec's Traité de

L'Auscultation Mediate et des Maladies
des Poumous et du coeur, 2d edit. 1826.
This last work is particularly interesting and
valuable, as are all the works of that author.

(e) 2 Bell, 56.

(f) 3Good, 485.

(g) 2. Bell, 58.

(h) Id. 59.

(i) Id. 56 to 70.

(j) 3 Good, 482; 1 Bost. 352 to 354, 361, and quare if this does not arise from an imperfect congenital communication of the two auricles, as above.

(k) 2 Bell, 73 to 81; 2 Good, 492.

Defects and diseases of the heart.(d) Malformation.

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is obstruction from disease of the semilunar valves of the aorta, but it
may arise from various other causes. Again, the walls of the ventricles
may become soft and thin, so that even the pressure of the finger may
rupture the texture of the wall without difficulty. This, when accom-
panied by dilatation of the ventricle, is called “passive aneurism.” In
this condition of the heart its walls may yield or give way, and occasion
sudden death; but such a rupture never occurs unless caused by external
violence, nor without some previous degeneration of the muscular struc-
ture of the organ.” (!)
But the aneurism of the aorta is a disease more frequent and more
dreadful than all the others. It is a disease more frequent in the de-
cline of life than at earlier periods. The aorta then begins to ossify;
its middle coat is converted into a hardish bony substance, commencing
in various points, and extending throughout a considerable portion of the
calibre of the vessel. Thus the elasticity of the artery and its muscular
power is lost. In this state it may burst, and uniformly destroy life
instantaneously. (m) There may also be an aneurismal enlargement of
the larger vessels in the immediate neighbourhood of the heart. (n) These
disorders sometimes arise from too violent exertions, independent of all
predisposition; sometimes from blows; more frequently from shocks or
falls; but still more often from those kinds of exertions which are accom-
panied with a rapid pulse and hurried respiration. (0) As to the symp-
toms, palpitation and quick breathing are the most common, but these
may be symptoms of quite different disorders. (p)
For aneurism of the aorta, rest, with abstemious diet, repeated small
bleedings, issues in the region of the heart, and attention to the circula-
tion by dietetic means, it is said, is all that can be done. (q)
In a very valuable recent publication Angina Pectoris, or acute
breast pain, has been treated as a distinct disorder, arising from a structural
disease in the heart or aorta, or both, or in some of its vessels too much

accelerating the flow of blood, or suddenly increasing the action of the

heart, and occasioning most agonizing pain, and which is to be treated differently during the paroxysm and in the interval, as there directed; (r) and in Sauvages this affection is termed Cardiogmus Cordis Sinistic, importing that this disorder proceeds from the left side of the heart; (s) whilst, according to others, angina pectoris is to be classed amongst the diseases of the respiratory functions, and affecting the lungs. (s) But the affection was not recognized as a distinct disease by medical authors until Dr. Heberden described it as such in the Medical Transactions of the London College of Physicians; (s) and one of the ablest anatomists of the present time still insists, that angina pectoris is a symptom of more than one disease of the heart, and is not of itself a disease. Its seat seems to be usually in the heart, or in some of the organs of circulation, and not in those of respiration. It has by Dr. Copland, in his valuable work, been recently defined to be “acute constrictory pain at the lower part of the sternum, inclining to the left side, and extending to the arm, accompanied with great anxiety, difficulty of breathing, tendency to syncope, and feeling of approaching dissolution,” and the alleviating remedies are there described. (s)

(1) I have been favoured with the above (p) Bell, 87.
passage between inverted commas by a (q) Liz. part ii. p. 165,166.

most experienced anatomist. (r) Cyclop. Prac. Med. tit. Angina Pec(m) Smith, 37; 2 Bell, 82,83; Lizars, toris, 81 to 95.

part ii. p. 163, 164, 168. (s) Copland, Dict. Pract. Med, tit. An(n) 3 Good, 473. gina Pectoris.

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The notion of what is commonly termed a broken heart, merely from mental suffering, seems to be questionable; and it is said that though violent passions of the mind very commonly produce syncope, yet that the person must have laboured under some previous organic affection of the heart or its vessels if death ensue. (u)

Wounds of the heart, even of the slightest and most superficial kind, have been generally considered as fatal, and the exceptions are few. The heart cannot be wounded without the pericardium, which surrounds it, being injured; but that membrane may be pierced without extending to the heart itself, and wounds of the pericardium merely are not necessarily mortal. (+)

2. OF THE ARTERIEs.(y)

The Arteries have been termed vital agents, endued with the properties of living matter, and forming part of an organized system endowed with vital powers, and have an important share in the circulation of the blood, (z) and they are stated to be in number about 1000, (a) but at least, as regards the named arteries, there are not perhaps even 300.

Arteries are elastic canals or vessels receiving and conveying the blood

from the heart to the different parts of the body, whereas reins carry

back the blood from the different parts to the heart; arteries are also distinguishable from veins by their pulsation. It has been observed, that to the surgeon the knowledge of the arterial system is valuable beyond calculation or belief, for he can perform no operation in which arteries are not engaged, nor can he cure any great wound in which arteries are not first to be tied, and without a knowledge of the arteries he can neither reason correctly nor act safely. (b) Nerves accompany and influence the arteries; the lymphatics and veins twine round them; the glands and

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various organs contain a large distribution of them. The intimate ,

structure of parts is known only by understanding such distribution
of their vessels; and as each individual part is nourished by arteries, he
who has studied the arteries thoroughly, possesses a more general know-
ledge of the whole; (c) so that every surgeon ought to learn familiarly
the general distribution of the arterial system. (d)
The original and principal trunks of the arteries, or of those which
arise from the heart, are two in number, the pulmonary artery and aorta,
both of which are nearly of the same diameter; and the measure of each,
on being slit, is about three and three-eighth inches, or, according to
others, the area of the aorta is about three-fourths of a square inch. (e
The pulmonary artery arises from the right ventricle of the heart, an
conveys the blood as there received from the veins into the lungs, where
it is renovated and returned back, as hereafter described, to another
o: of the heart, and from thence the blood is propelled into the aorta.
rom the latter, all the other arteries are derived, and branches are dis-
persed through the whole body. (f)

(t) Liz. partii. p. 16; 4 Good, 121; as (c) 2 Bell, Introd. xxii.; 2 Good, 12, 4

to rupture of aorta of Geo. 2d, see 3 Paris 24.

& Fonb. 58; Smith, 37. (d) 2 Bell, Introd. 25, 26.
(u) 2 Paris & Fonb. 26, 27. (e) 1 Bost. 417.
(1) Smith, 277. (f) Ell. Blum. 82; 2 Good, 28;
(y) Angiology, Quain. 35, ante, 51. 2 Bell, 92; Liz. part ii. 170; Coop. Dict.
(z) 1 Bost. 391. tit. Aorta, 213,215, tit. Aneurism; Cyclop.
(a) 2. Bell, Introd. xxv. ante, 5. same title, p. 104.

(b)2 Bell, Anat. Introd.23; El. Blum, 81.

The pulmonary artery and the aorta.

CHAP. W.

Sect. I. The ARTERIEs.

The Aorta and its branches, being similar arteries.

It is the trunk from which the general tree of the arteries is to be explained. It commences deep in the flesh or muscles of the left side of the heart, and mounts upwards and backwards from the heart till it begins to form its peculiar arch or curvature, and then bends downwards to the left side of the spine opposite the third or fourth dorsal vertebra, along which it proceeds gradually, reaching the front of the spinal column through the diaphragm into the abdomen. At the commencement of the aorta the two coronary arteries branch from it, and proceed on the heart itself, in order to supply it and cause its successive contractions ; and from the arch of the aorta go off three great arteries, which rise to the head, or bend sideways towards the arms, and so nourish all the upper parts of the body, viz. first, the arteria innominata, dividing into the right carotid and right subclavian artery. Secondly, the left carotid artery, going to the head; and thirdly, the left subclavian artery, going to the left arm. (g)

The aorta in the chest nourishes the lungs by the bronchial or small nutritient vessels, and when it gets below the diaphragm gives three great abdominal arteries; first, the caeliac, going in three branches, one to the liver, one to the stomach, and one to the spleen; secondly, the superior mesenteric, which furnishes all the smaller and a great portion of the large intestines; and thirdly, the loner mesenteric artery, which supplies a

rtion of the great intestines down to the rectum. The arteries of the

idneys and of the testicles may be added to these, and are branches of the aorta, and afterwards the aorta divides into two great branches for the pelvis and legs. The iliac arteries are the two great branches into which the aorta divides within the abdomen, and these again are each subdivided into two great arteries, the internal iliacs to supply the pelvis, and the external iliacs to go to the thigh. These are only a very few of the principal great arteries; and there are a great many others, formed by successive divisions and subdivisions of these, which are distributed to every part of the body, receiving names according either to their size or to the importance of their distribution. (h) The vena cava, proceeding upwards, leaves the aorta a little above the pelvis, and inclines gradually towards the right, that it may enter into the right side of the heart, which it does by passing under the liver, and penetrating the diaphragm. (i)

The F. trunks run in the centre or deepest and most protected parts of the body and extremities, where they are the least exposed to danger, deriving support or defence from the bones and muscles. (k) They are distinguished from veins by the whiteness of their colour and thickness of their coats; also in the circumstance of their not having like veins any valves, except at the roots of the aorta and pulmonary artery. (l) Arteries thus commencing from the aorta or from themselves are found to terminate in several ways, as by one artery anastomising or inosculating, that is, communicating with another, or in red veins, or in glands or follicles, by secerning or secreting orifices which separate a fluid from the general mass of blood by exhalent vessels, which discharge their contents into the internal cavities, or upon the external surface of the body; and finally, arteries terminate in that structure called erectile tissue. (m) . Other authors observe, that in the present state of our knowledge the umbilical vessels are to be regarded as the only exceptions

(g) 2. Bell, 93, 94. (k) 2 Good, 25, 26; Tuson, 101. (h) Id. 221. (l) 2 Good. 13; 1 Bost. 340. (i) Id. 97 to 321 ; see an eneumera. (m) Ell. Blum. 83; Tuson, 102; 2 tion and plates 3 Gregory's Economy of Good, 3. Nature, 243 to 255.

to the termination of arteries in veins; (n) at all events many of the
arteries do not terminate immediately in veins, but in some degree the
effete and altered blood in the arteries first passes into the capillaries,
which are hair-like terminations of the arteries, and thence into the in-
cipient radicles of the veins, which convey it into the larger branches,
from which it is forwarded to the trunks that open into the right auricle
of the heart. (0) Dr. Good says, that in reality the capillary system con-
stantly intervenes between the arteries and the veins. (p). Many phy-
siologists insist that the large arteries are merely mechanical tubes to
convey the blood to remote parts, and the capillaries, in which the arteries
terminate, as the part of the vascular system in which all the important
objects of the circulation are mainly prepared and accomplished as nu-
tritious secretion, the oxidation of the blood, its decarbonization, &c. (q)
The distinction between artery and veins at the point of union is lost. (r)
Every artery has its sheath, which is a tissue of cellular membrane
surrounding it, and material to be distinguished by the surgeon from the
artery itself (s) Each artery also has or rather is composed of three
arterial coats, now generally termed external, middle, and internal. (t)
The exterior, by some called the tunica cellulosa propria, by others the
nervous cartilaginous tendinous, &c., and is composed of condensed
cellular membrane, externally more lax, internally more and more com-
pact, and blood vessels are seen creeping upon it; and it gives great tone
and elasticity to the arteries. The middle coat consists of transverse fibres,
lunated or falciform, and almost of a fleshy nature; hence this has the
name of muscular coat, and appears to be the chief seat of the vital
power of the arteries, and is the chief assisting power propelling the cir-
culation of the blood. The inner coat, lining the cavity of the arteries,
is highly polished and smooth, but which is much more distinct in the
trunks and larger branches than in the smaller vessels. (u)
The powers of an artery in moving forward the blood are elasticity and
muscularity. Their elasticity marks their difference, from the veins
keeping their sides apart and open, even when they are empty; and the
muscular power increases in the proportion in which the artery is remote
from the heart, which compensates the decreased power of the heart the
greater the distance from it, and thus the blood is circulated with nearly
equal velocity throughout the arteries. (a)
Dr. Bostock makes the following observation on the arteries:—The
arteries which perform the office of conveying the blood from the heart
are flexible elastic tubes, not perfectly cylindrical, but conical, the nar-
rower end of the cone being situated towards the heart. (y). The arteries
are principally composed of membranous matter, formed into distinct
layers, and composing what are called the coats of the arteries. Of these
membranous coats, anatomists usually describe two as possessing a suf-
ficiently determined structure to be easily distinguished from each other,
the outer one partaking more of the nature of the cellular texture, and
therefore ài. the cellular, (2) and an inner membrane, white, firm, and
smooth, possessing more of the physical properties of tendon, and by
some erroneously called the nervous coat, but more properly the interior

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Blum. 81, 82; Lizars, part ii. p. 177; and () See Observations, 1 Bost. 338, note 9. see a good practical description in Coop.

CHAP. V. Sect. I. The ARTERIEs.

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