Book - Handbook of Pathological Anatomy 2.7
Embryology - 16 Apr 2024    Expand to Translate
|
|---|
| Google Translate - select your language from the list shown below (this will open a new external page) |
|
العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt These external translations are automated and may not be accurate. (More? About Translations) |
Meckel JF. Handbook of Pathological Anatomy (Handbuch der pathologischen Anatomie) Vol. 2. (1812) Leipzig.
- Ligaments: I. Trunk | II. Head | III. Extremities Muscles: I. Trunk | II. Head | III. Extremities Angiology: I. Heart | II. Body or Aorta Arteries | III. Body Veins| IV. Pulmonary Artery | V. Pulmonary Veins | VI. Lymphatic System | VII. A Comparison of Vascular System Nervous System: I. Central Nervous System
| Historic Disclaimer - information about historic embryology pages |
|---|
 |
Section I. Of the Heart
Chapter I. General Remarks
§ 1294. The heart (cor) is a hollow muscle irregularly conical or pyramidal, situated in the centre of the chest, between the two lungs, and inclosed in a special envelop called the pericardium. Its vessels are numerous, but it has few nerves : it is formed of several cavities, some of which are separated, while others communicate together. Its tissue is formed of fibres united in superimposed layers, and is connected on one side with the large venous trunks of the lungs and body, and on the other with the large arterial trunks of both. Each of these characters deserves to be specially considered.
I. FORM.
§ 1295. The shape of the heart is that of a cone or an irregular pyramid. We distinguish in it a broad and thick base (basis) and a summit (apex), which is generally blunt and bifurcated, an upper and anterior face which is concave, and an inferior and posterior which is smaller and flatter ; two edges, a posterior which is thick and pointed, the anterior is smaller, shorter, thin, and sharp.
The base of the heart is formed, properly speaking, by that part of the organ directly connected with the veins : we may then term it the venous portion of the heart (pars cordis venosa). However we generally apply the term base of the heart to the upper region of the arterial portion. The venous portion is formed of two auricles. It is separated from the next by a large groove, called the groove of the base , the auricuto-ventricular groove , or circular groove ( sulcus baseos , s. alrio-ventricularis, s. circularis). Its form is an oblong square and its breadth exceeds its height.
The succeding portion, which is situated before the auriculo-ventricular groove, is directly connected with the large arterial trunks. We may then term it the arterial portion of the heart (pars arteriosa cordis). It is formed by the two ventricles. It terminates in a blunt summit, which is usually more or less evidently grooved. This groove is sometimes very large.
ANGEIOLOGY.
185
The longitudinal groove (sulcus cordis longitudinales superior et inferior) exists on both faces of the heart, from its base to its summit, and
consequently in all its length.
The principal branches of the nutricious vessels of the organ are situated in these grooves : they communicate on the side of the base by a groove, which descends perpendicularly between the two auricles, and on the summit by the depression observed in this place. They mark the course of the septum within the heart (septum cordis).
§ 1396. The septum passes also across the venous portion of the heart or the auricles as well as its arterial portion or the ventricles. It separates completely these two synonymous parts, and consequently divides the heart into a right or an anterior and a posterior or left half. That part which passes between the auricles is called the septum atriorum, and that between the ventricles is called the septum ventricidorum. The right part of the heart is called the pulmonary heart (cor pulmonale), because the pulmonary artery arises from it, or the heart of the black blood, from the color of this fluid within it. The left is termed the aortal heart (cor aorticum ), because the aorta arises from it, or the heart of red blood, from the color of the blood within it. We employ sometimes also the terms of first ventricle, to designate the anterior, and second ventricle, to mark the posterior ; but these are less convenient.
II. WEIGHT AND SIZE.
§ 1297. The weight of the heart in a fully grown man is about ten ounces ; whence it is to that of the whole body as 1 is to 200.
Its length, measured from the centre of the auricles, is between five and six inches its mean length is five and a half inches, four of which are for the ventricles and one and a half for the auricles. The breadth of the ventricles united is generally three inches at their base and that of the auricles is three and a half inches. (1 )
III. SITUATION.
§ 1298. The heart is placed obliquely from right to left, from behind forward, and from above downward ; so that its base is nearly opposite
(1) A knowledge of the perfectly normal proportions of the heart in the healthy state is very important to the physician, since without it he can establish no certain diagnosis of the diseases of the central organ of the circulation. We cannot do better than to quote the following passage of Laennec on this subject : “ The heart, in cluding the auricles, should be equal to, a little less, or a little larger than the first of the subject. The walls of the left ventricle should be a little more than twice as thick as the walls of the right ventricle ; they should not collapse on cutting into the ventricle. The right ventricle, a little larger than the left, presenting- smaller fleshy pillars, although its parietes are thinner, ought to collapse after the incision.†(De V auscultation médiate, vol. ii. p. 270.) “Reason teaches and observation proves, that in a well formed subject the ca\ ities of the heart are nearly equal ; butas the parietes of the auricles are very thin and those of the ventricles are much thicker, it follows that the auricles form only one third of the whole volume of the organ or the half of that of the ventricles.†( lb .) ~ F. T.
VOL. II.
24
1S6
DESCRIPTIVE ANATOMY.
the eighth dorsal vertebra, from which it is separated by the esophagus and aorta, and its summit corresponds to the cartilage of the sixth
rib, or to the interval, which separates it from the next. Its lower face,
which is flattened, corresponds to the upper face of the central tendon
of the diaphragm, and the upper to the central and left portion of the
anterior wall of the chest.
IV. TEXTURE.
§ 1299. The heart is formed of several layers of muscular fibres, situated between two thin, smooth, and polished membranes, the inner and outer membranes of the heart. The latter is the inner layer of the pericardium.
The outer surface of the heart is smooth and uniform in relation to the inner, even when we have removed the outer membrane.
The inner surface is very uneven and reticulated, which arises from its being formed of numerous rounded, flat, and distinct muscles, which intercross continually and which are called fleshy •pillars ( trabeculœ carneœ). The mnscular substance of the heart is generally harder, more solid, and more elastic than that of other muscles.
As the arrangement of these fibres(l) differs wholly in the venous portion from what it is in the arterial portion, as it is not exactly the same in the right and left portions, and as it finally differs according to the subject, all that can be said generally may be reduced to the following corollaries :(2)
1st. The directions of the layers are more or less opposite. But in the recent state, far from being entirely separated from each other, they intercross differently ; so that all those of one portion of the heart constantly contract uniformly and diminish the cavity they circumscribe in every direction.
The union of the different layers takes place partly by more or less manifest muscular fibres.
2d. The fibres which form the layers are united in fasciculi of various sizes, which vary more or less in their origin and their direction, and which are often separated by greater or less spaces. These fasciculi are sometimes rounded and sometimes flattened, — a difference which seems to depend on determinate laws, since it is constant in the different regions of the heart. For instance the right and left ventricles
(1) Wolff, De online fibrarum muscularium cordis, diss. vii. De stratis fibrarum in Universum. In nov. act. petrop., vol. iii., 1785, p. 227-249. — Gerdy, loc. cit., p. 101. — Vaust, loc. cit., p. 102, etc.
(2) Gerdy has established a law, that all the fibres, whatever is their extent, situa tion, and direction, form webs, which are convex toward the point of the heart, and which are nearly superficial at one extremity and deep at the other ; so that for instance the external or internal fibres are the same reversed, and having passed through the thickness of the ventricle. The extremities of these muscular webs are constantly inserted in the base of the heart, around the different auricular'and arterial orifices of the ventricles, either directly or by tendons attached to the auriculoventricular valves (loc. cit., p. 101). F. T.
ANGEIOLOGY.
1S7
are not similar in this respect nor in regard to the arrangement of their
fibres, and the same is true of other parts also. Thus the inner layers
are generally rounded and form fleshy pillars. The auricular appendages of the auricles are formed of rounded fasciculi, and the auricles of
flattened fasciculi.
From this arrangement we may deduce that the firmest parts are formed of rounded fasciculi. But the fibres and the fasciculi formed by them are united by intermediate fibres, which may be distinguished with facility.
The fibres and fasciculi are every wdrere interlaced with each other, conformably withall the in voluntary muscles. They are united principally in two ways : sometimes the ends of the fibres and fasciculi join, and sometimes they are united by intermediate filaments, which arise from their lateral portions.
In the first case, either the fasciculi go to meet each other and the extremities of those which continue together intermix like the teeth of a saw, as is the case with the digitations of several adjacent muscles, or some fibres are attached obliquely to others at acute angles, as the fibres of the penniform muscles are implanted in their tendons, and finally, as is the case most generally, the fibres or fasciculi which go side by side unite at very acute angles.
The lateral union takes place principally between the insulated fibres and the small fasciculi of fibres, especially in the outer layer. Sometimes it is irregular ; so that those fibres which are evidently separated in the rest of their course are placed one against another in a part of this same course, whence the reticulated structure is more or less evident. It is sometimes regular, and we see oblique fibres going from each side, which unite. The redness and determinate form of the intermediate filaments always demonstrate that they are not formed of cellular tissue but of real muscular substance.
The mode in which the filaments are united also presents determinate differences in the different regions of the heart.
3d. In the ventricles, the external layers go obliquely downward, backward, and from right to left. The direction of the central is opposite, and the most internal, which form the fleshy pillars, extend longitudinally from the summit to the base.
On the contrary, the transverse direction predominates in the auricles. The external layer, which is the strongest, proceeds in this direction, while the internal, which forms only insulated fasciculi, has a longitudinal direction.
4th. All the external layers are not equally extended. Generally the external layers are those only which cover all the surface of the ventricles ; the central are smaller and occupy only a third of the heart. If we except the most internal, that which forms the fleshy pillars, they diminish in direct ratio to their depth. They disappear first at the summit of the organ, and in reascending from this point to the base of the ventricles, they are deeper and deeper ; so that the deepest
ISS
DESCRIPTIVE ANATOMY.
arc found only at the base. Hence this part of the heart is the
thickest.
We observe also occasional spaces between the layers, which extend the whole length or all the breadth of the ventricles.
5th. The outer layers differ from the central ones, inasmuch as they are stronger and their fibres are more intimately united together.
Thus the fibres and the fasciculi of the inner layers are more easily demonstrated. But the external forcibly embrace and compress these latter ; so that they contribute essentially to the firmness of the heart.
6th. The fibres of the two portions of the heart are not continuous, at least not all of them, with each other, so that the same layers are reflected on the two ; but the fibres of the two ventricles terminate in the septum. The upper and lower faces of the heart are not arranged in precisely the same manner : the separation is seen with more difficulty in the first than in the second. We remark also three different arrangements in the upper face. In fact, either we cannot distinguish the least trace of separation and the fibres are uninteruptedly continuous with each other, or two fibres are in fact applied one on the other, but a species of suture serves as a line of demarkation between them, or finally they mingle with each other by digitations.
Wolff states that on the lower face, the fibres of the two ventricles are separated by a distinct and very broad band, formed of longitudinal fibres, and which diminishes insensibly from the base to the summit, to which these fibres are attached on the two sides. But we have usually found but a slight, and often no trace of this arrangement.
7th. The upper extremities of the fibres of the heart are attached to a fibro-cartilaginous tissue,(l) formed
a. Of two oblong, rounded projections or tubercles, usually three or four lines long, little less than a line thick, seen on both sides of the orifice of the aorta.
b. Of a thin band, which surrounds the posterior part of the circumference of the aorta and unites the two tubercles.
c. Of four filaments, placed in the circular groove on the base of the heart, two on the right and two on the left, an anterior and posterior on each side. Below these four filaments the two anterior arise from the tubercles. The right anterior goes into the anterior and upper part of the circular groove ; the left into the upper and posterior part. The posterior two arise by a very short common trunk, which is only a few lines long, from the band which unites the two tubercles, near that of the right side, and proceed in an opposite direction to the lower part of the circumference of the circular groove.
These anterior and posterior filaments are situated at the venous orifices of the ventricles. They do not surround the base of the heart
(1) C. D. F. Wolff, Dc or dine fibr arum muscularium cordis , Diss. ii., de textu cartilagine ocordis , sivc dcfilis cartilagineo-osseis corumque in basi cordis distribution. In Act. Petropol., 1781, vol. i. p. 211. — Gerdy, loc. cit., du tissu albugine cardiaque , p. 97.
A NGEIOLOGY,
189
and form a complete ring, but terminate near the edges of each orifice
and gradually lose themselves in the cellular tis'sue.
This cartilaginous tissue is surrounded entirely by a thin, firm, but loose sheath, a real perichondrium. It is covered more externally by the outer membrane of the heart and internally by its inner membrane.
The external muscular or superficial fibres arise principally from the cartilaginous tubercles and filaments, and from the cellular tissue between the extremities of the latter ; so that the fibres, which come from the tubercles and from the origin of the filaments, adhere to them very intimately, while the others are united only by a cellular sheath which surrounds them.
v. vessels. (1)
§ 1300. The blood-vessels of the heart are proportionally very large and are called the coronary vessels ( vasa coronaria cordis). The coronary arteries and veins resemble each other in many respects :
1st. These vessels (the arteries) arise directly from the beginning of the trunks of the vessels of the body, or they (the veins) open directly into the heart.
2d. They turn around the base of the heart in the circular groove, whence they send toward the summit large branches which arise at almost right angles : these go to the ventricles and proceed along the heart, while the others are smaller and follow an opposite direction, proceeding to the auricles.
3d. The large trunks and the large branches extend on the outer face of the organ and ramify internally.
4th. The veins have valves at the places where they open but not in their course. There are two arteries of nearly equal calibers, while we find only a single large coronary vein, which is constant ; but beside this last we observe several, which are smaller, which open 'directly into the heart, but not constantly, except into the right part of the organ, and particularly into the right auricle : they do not open, even, except into the septum, and they do not empty their blood into the left part of the heart, (2) as some anatomists have pretended, and among others Vieussens(3) and Thebesius.(4) In fact, Abernethy has very recently supported this latter opinion, viz. that the venous blood of the heart mixes with the arterial blood which nourishes the body, without passing through the lungs ; he has only modified it by saying, that these orifices of the coronary veins in the left portion of the organ serve principally to prevent repletion of the right portion in those cases where the passage of the blood through the lungs is obstructed ; because,
(1) Haller, De vasis cordis propriis, Gottingen. 1737. — Iterates observationes, 1739. — Geisler, Commentatio de sanguinis per vasa coronaria cordimotu, Leipsic, 1743.
(2) Sabatier, Sur les veines de Thebesius ; in the Traité d’anat., vol. iii.
(3) Nouvelles découvertes sur le cœur, Montpelier, 1706. — Traité du cœur, 1715.
(4) De circula sanguinis in corde, Leipsic, 1708. — De circulo sanguinis per cor , Leipsic, 1759.
190
DESCRIPTIVE ANATOMY,
having injected the cardiac arteries and veins in a subject whose lungs
were diseased, he has seen the fluid penetrate into the left ventricle by
broad openings. But as generally injections, even when very fine,
transude on all the inner face, although no venous orifices are perceptible on the left side, we have reason to admit that the openings existing in the cases observed by Abernethy were produced accidentally,
either during life or after death, by obstacles to the course of the injection, on account of the feeble resistance of the tunics of the veins weakened by disease, and considerably distended, both by the blood accumulated in these vessels and by the injected mass.
VI. NERVES.
§ 1301. The nerves(l) of the heart are proportionally smaller than those of the voluntary muscles. They arise from the upper and lower cervical ganglions of the great sympathetic nerve, from the cervical portion of the nerve between these two ganglions, or from the central ganglion sometimes found in this place. Some arise directly from the nerve, others from the plexuses formed by the filaments which come from the ganglions and by others sent off by the pneumo- gastric nerve.
The relations of the nerves of the heart with its muscular substance have been the subjects of dispute. Some anatomists, Behrends(2) among others, deny that this substance, and consequently that the heart, possesses nerves, which they pretend are distributed only to the cardiac vessels. Others on the contrary, as Scarpa, Munniks,(3) and Zeirenner,(4) maintain that they really go to the heart as well as to all other muscles.
The partisans of the first hypothesis adduce the following arguments :
1st. Anatomical examination, whence it results that the cardiac nerves, which we cannot follow except to the third ramification of the coronary arteries, do not enter the substance of the heart but go only to the arteries. (5)
2d. The origin of the cardiac nerves ; they arise from the great sympathetic nerve, the ramifications of which go only to the arteries. (6)
(1) J. F.. Neubauer, Descriptif) nervorum cardiacorum, Frankfort and Leipsic,
1772. He has figured the nerves of the right side. — E. P. Andersch, De nervis ; in the
Nov. comm. Gœtt ., vol. ii., and Königsberg, 1797. He has represented those of the left
side. These figures have been copied in Haase, Cerebri nervorumque corporis humant
repetita, Leipsic, 1781. — A. Scarpa, Tabulœ neurologicæ ad illuslrandum historiam
anatomicam cardiacorum nervorum cerebri , glossopharyngœi et pharyngæi ex octavo
cerebri, Pavia, 1794.
(2) J. Behrends, Diss. qua demonstratur cor nervis carere, additâ disquisitione de vi nervorum arteriös cingentium, Mayence, 1792.— A. T. N. Zerrenner, An cor nervis careat iisque carere possit? Erford, 1794.
(3) Observationes varice. Diss. auat. med., Groningue, 1805, 1-17.
(4) Zerrenner, An cor nervis careat iisque carere possit ? Erford, 1794.
(5) Behrends, loc. cit , p. 5, 8.
(6) Id., ibid., p. 8.
ANGEIOLOGY.
191
3d. The smallness of those nerves which is in direct ratio with the
thinness of the fibrous coat of the arteries,(l) and which contrasts on
the contrary with this law, that the number and size of the nerves
correspond to the power and frequency of the motions of the muscles.^)
4 th. The insensibility of the heart, the motions of which are independent of the nervous system, since it beats regularly although removed from the body, (3) and the excitement of the nerves, whether mechanically or dynamically, by means of galvanic electricity, do not alter its motions, (4) and its pulsations are not deranged when the nervous system is paralyzed as in apoplexy. (5)
5th. The integrity of the motions of the heart, notwithstanding the administration of opium. (6)
But all these arguments can be refuted with greater or less facili'y. In fact :
1st. The manner in which the cardiac nerves are distributed and their proportion both to the muscular substance and to the vessels, do not differ essentially from what is seen in the same respects in the voluntary muscles. (7) Here also the nerves and the ramifications of the vessels are very compactly situated in regard to each other, and we do not see the nerves unite to the muscular substance. Besides the cardiac nerves are closely connected with the vessels only in their largest branches, and not at all in many animals.
2d. The muscular substance of the heart is only a greater development of the fibrous membrane of the vascular system, so that the distribution of the branches of the great sympathetic nerve within it does not present an aberration from the type of this nerve.
3d. The cardiac nerves possess more medullary substance than those of the voluntary muscles. They arise from the ganglions of the great sympathetic nerve, and through them from ail the _ spinal marrow. Their action is probably favored by the mutual contact of the blood and of the inner face of the heart ; very probably also the size of the nerves which go to the voluntary muscles relates to their functions which is to conduct the influence of the will.
4th. The facts cited in the fourth paragraph are explained partly by the smallness and partly by the texture especially the softness and gelatinous nature of the cardiac nerves, and from the circumstance that they arise from the ganglions. Besides they are correct only to a certain extent, since the motions of the heart are not entirely independent of the nervous system. The passions have a marked influence on the number and strength of its pulsations. Impressions of
(1) Behrcnds, loc. cit., p. 8, 9.
(2) Id., ibid., p. 10.
(3) Id., ibid., p. 11.
(4) Id., ibid., p. 20.
(5) Id., ibid., p. 12.
(6) Id., ibid., p. 11.
(7) Scarpa, loc. cit., § 13. — Munniks, loc. cit., p. 6.
192
DESCRIPTIVE ANATOMY.
every kind on the nervous system modify its motions more or less sensibly.(l)
In fact several observers, particularly Valli, Volta, Klein, (2) and Bichat, have doubted the influence of electricity on the motions of the heart; but the observations of Fowler, Schmuck, Pfaff,(3) Rossi, (4) Giulio,(5) Humboldt, (6) Munniks,(7) and Nysten, and our own also, prove it to be real.
The non-affection of the heart in paralysis of the brain proves nothing' in regard to the relations between the nerves and this organ, since the irritability of the voluntary muscles is not altered in apoplexy. This apparent difference depends only on that between the excitants of the voluntary and involuntary muscles. In fact the excitant of the first is the influence of the brain, and that of the second the substance contained in their cavity, which in the present case is the blood. The motions of the heart continue also in cerebral paralysis, while those of the other muscles are not performed ; the activity of these last seems extinct while it is only no longer seen.
5th. The observations of Haller, of Fontana, of Whytt,(8) and of Alexander, (9) prove that the heart, like the voluntary muscles, is sensible to the influence of opium, whether the narcotic acts directly upon it, or is placed in contact with the nervous system or with any organ whatever. These observations and experiments prove that the relation between the heart and the nerves is perfectly like that between the nerves and muscles generally, and more, because the effect of opium upon the heart is much more evident when this substance is placed in relation with the nervous substance than when applied directly to the heart.
VII. VENOUS PORTION.
§ 1302. The characters of the venous for lion of the heart, (10) the auricles, are,
1st. The muscular substance of its parietes is so thin that the two membranes of the heart touch in several places.
2d. Its form is irregularly quadrilateral.
(1) See on this subject Legallois, Experiences sur le principe de la vie, Paris, 1812, . — Wilson Philip, in the Phil. Trans ., 1815, part i. p. 65-97 ; part ii. p. 224-246. — Ici. An experimental inquiry into the laws of the vital functions, London, 1818.
(2) In Pfaflf, Vcber thicrischc Electricitât und Reizbarkeit, p. 119.
(3) In PfaflF, loc. cit., p. 140.
(4) Mém. de Turin , vol. vi.
(5) Voig’ht, Magazin , vol. v. p. 161.
(6) Ueber die gereizte Muskel-und Nervenfaser , vol. i. p. 340-349.
(7) Loc. cit., p. 115.
(8) In Pfaffj loc. cit., p. 140.
(9) Memoirs of the Manchester society, vol. i. p. 98.
(10) Ruysch, Epist. anat. problemala décima de auricularum. cordis earumque fibrarum molricium structura, Amsterdam, 1725. — A. F. Walther, De structura cordis auricularum, Leipsic.
ANGEIOLOGY.
193
3d. It is composed of a part into which the veins open directly the
cavity of the auricle , the sac (sinus), and another upper and anterior,
the auricular appendix (auricula), which projects above the sac.
The exact limits of these two parts cannot be pointed out, or rather anatomists do not distinguish them according to the same principles on the right and left sides. On the left side the appendix is readily distinguished from the sac, because it suddenly forms a very rounded projection, which is much narrower, and has thicker walls on the upper anteiior and left angle. On the right side, on the contrary, this name is applied to a part, the walls of which are very thick, which is formed on the left by the confluence of the two venæ eavæ, terminates above in a blunt summit, and which is not sensibly separated from the rest, while, if we remained true to the analogy, this term should be applied only to the small appendix which terminates the auricle above, and which is elevated on the left along the vena cava superior.
4th. It is directly continuous with the venous trunks which open into it.
VIII. ARTERIAL PORTION.
§ 1302. The characters of the arterial portion of the heart, the 'ventricles, are,
1st. Their parietes are thicker, so that the internal and the external membranes are every where separated from each other by a muscular substance. The thickness of the parietes of each portion of the heart is then in direct ratio with the extent passed through by the blood it sends forward.
2d. The arterial portion is considerably larger and broader than the venous portion.
3d. Its external form is elongated, rounded, and pyramidal, and determines, properly speaking, the form of the whole heart.
4 th. At its upper extremity are two openings, the venous and the arterial, which establish the communication, the first between the ventricle and the auricle, and the second between the ventricle and the artery w hich arises from it. The venous orifice is almost perpendicular ; its direction is from before backward and from right to left ; the arterial is almost horizontal and is situated a little above the former farther inward and nearer the septum.
Both are rounded j the venous is broader than the arterial. Its form is elliptical, while the latter is nearly circular.
Neither the venous nor the arterial opening is perfectly loose ; both have valves. The valves placed at the arterial opening are very similar in their arrangement to those found in the common veins they are however much larger and are usually three in number. Thenconvex and attached edge looks toward the heart while the loose edge, which has two concavities and which is thicker than the rest of the membrane, is turned toward the cavity of the artery. In the centre
Vol. II. 25
194
DESCRIPTIVE ANATOMY.
of the latter we observe a fibro-cartilaginous tubercle ( nod-ulus ). The
blood which comes from the ventricle pushes them toward the circumference of the artery and against its parietes. On the contrary the
blood which tends from its specific gravity to return from the artery
into the ventricle separates them from these same parietes, their loose
edges then touch, and they form a horizontal septum between the
cavity of the artery and the ventricle, which prevents the reflux of
the blood into the latter. The tubercles complete this septum and
close the space in the centre of the artery between the three valves.
The valves of the venous orifice differ from those of the arterial opening, and from all other valves, since they are attached much more firmly, hence they close more completely the opening around which they are placed. A narrow cartilaginous ring, which is not however perfect, exists on all the circumference of the venous opening ; this sometimes ossifies in advanced age, especially in the left portion of the heart, and is situated deeply between the muscular fibres of the ventricle and those of the auricle.
This is the cartilaginous tissue already described as the origin of the external muscular fibres of the heart. The venous valve is attached to this tissue by its posterior edge, but its opposite and uneven edge, unlike that of all the other valves, is not loose ; many flat and solid tendinous filaments, which extend from the base to the summit of the heart, arise from the valve, on which they are often united or pass over it and go to the opposite part of the circumference of the heart, soon unite into larger cords, and are attached to the parietes of the heart, and principally to its fleshy pillars. As the latter shorten when the heart' contracts, the different parts of the valves then approach each other and the opening is forcibly closed. It is necessary that the loose edge of these valves should be thus attached since they must resist not only the weight of the blood like the other valves, but also the action of the muscular parietes of the heart, which forcibly push forward the arterial blood.
5th. The arterial portion of the heart is divided into an upper and lower half, which are separated by the upper part of the valve of the venous orifice at the upper and posterior parts of the ventricles, and which blend together at the summit of the heart, so that the ventricles, although resembling externally an elongated cone, form in fact two arched canals, convex forward, and the greatest convexity of which corresponds to the summit, and are more extensive in this part than in any other.
6th. The reticulated structure of the ventricles is much more distinct than that of the auricles. Some of the fleshy pillars form rounded, elongated projections, terminating in blunt summits (musculi papillares ), which go toward the base of the heart, and from the extremity of which several tendinous filaments proceed to attach themselves to the loose edges of the venous valves. Farther, those fleshy pillars which are attached by their two extremities, as well as those which have
r
ANGEIOLOGY.
195
one end loose, communicate with each other at intervals by tendinous
fibres. The direction of the principal fasciculi is longitudinal, the
smaller which unite the preceding are oblique. Near the summit the
reticulated texture is more and more developed, and the parietes become thinner in the same proportion.
IX. RIGHT AND LEFT PORTIONS.
§ 1303. 1st. The right half of the heart is considerably thinner than the left. This difference is very striking between the two ventricles, where the relation is generally as one to four or to five. Even then we find, as between the auricles and the ventricles generally, that the power of the parietes is in direct ratio with the space passed through by the blood winch comes from them. The greater thickness of the walls of the left ventricle determines the form of the whole arterial portion of the heart. The right wall formed only by the septum is convex, and the left appears fitted to it like a sling.
2d. The substance of the right side, especially that of the ventricle, is softer and looser than that of the left side.
3d. The right side is broader than the left after death.(l) This difference also is most marked between the two ventricles, but it is not yet determined if it exists constantly during life or supervenes only after death.
Many anatomists, particularly Lower, (2) Santorini, (3) Weiss, (4) Lieutaud,(5) and Sabatier, (6) have adopted the latter opinion, while most others favor the first.
This hypothesis has been supported sometimes by the result of measurement, and sometimes by the fact that the left ventricle is as much longer as the right is broader, and sometimes by experiments and observations, from which it has been concluded that the right side appears broader after death, only because it is more distended by the blood which remains stagnant in the lungs from their inaction, while previously the passage of the blood from the left ventricle was not obstructed ; whence the left ventricle seems to be narrower compared to the right, in proportion to the less quantity of pulmonary blood received by it through the pulmonary veins. In men and animals who have died suddenly from the injury of the large vessels, or of those which communicate with the right portion of the heart, when consequently this cause of the distention of the right ven (1) Helvétius, Sur l’inégalité de capacité qui se trouve entre les organes destinés à la circulation du sang , dans le corps de l’homme, et sur les changemens qui arrivent au sang enpassant par le poumon, in the Mêm. de Paris, 1718, p. 222-281.
(2) Loc. cit., p. 34.
(3) Loc. cit., p. 144, 145.
(4) De dextro cordis ventriculo postmortem ampliore, Altdorf, 1745.
(5) Essais anat., p. 230, 231.
(6) Sur /’inégale capacité des cavités du coeur et des vassieaux pulmonaires, in the Mém de Paris.
(7) Lieutaud has brought forward this argument.
196
DESCRIPTIVE ANATOMY.
tricle did not exist, the capacity of the two portions has been exactly
or nearly the same.(l) Finally, when the left ventricle is placed in
the same condition by means of a ligature as is the right ventricle at
the time of death; while on the contrary the blood is removed from
the latter by cutting the pulmonary artery, or the vena cava, we find
that the relation between the two ventricles is the inverse of that
which commonly exists, that is, that the right ventricle is narrower
than the left.(2)
The vein's appear much larger than the arteries after death, undoubtedly from the same cause.
To these experiments we may add that we sometimes find the right ventricle narrower than the left from the effect of disease, such as ossification or some other malady of the valves of the aorta, in which case the difference must be explained precisely in the same manner. We have before us several preparations in which, beside a considerable dilatation of the left ventricle arising from this cause, there is at the same time a great contraction of the right ventricle, proving that the results drawn from these facts cannot be opposed, by saying that the dilatation of the right cavity of the heart in the usual state of things should extend also to the left portion from the influence which it exercises on the veins and arteries of the body, and consequently that the right half is really larger during life since the left is itself distended. Since the cause of the greater distention of the right portion, that is, the more difficult passage of blood through the lungs, supervenes only at the moment of death, the opinion that the right ventricle is also more capacious during life cannot be sustained. (3)
That the cause above mentioned is that which increases the capacity of the light portion of the heart at the period of death only, is proved by the fact that the difference between the two portions of the organs varies with the cause of death, and that it increases in a direct ratio with the increase of the obstacle to the circulation of the blood in the lungs. Thus, in those animals killed by drowning, hanging, and suffocation, Colman has found the right ventricle generally twice the size^of the left, although its proportions commonly mentioned are much smaller.(4) In fact, Haller asserts that in one subject he found it three times as large as the left, (5) but the usual estimates are much less than this. Gordon says the relation is sometimes as 5 : 4,(6) Lieberkühn as 3 : 2,(7) Portal as 7 : 5,(8) Helvetius(9) and Legallois,(10)
(1) Weiss, loc. cit. — Sabatier, loc. cit.
(2) Sabatier, loc. cit.
(3) Haller, Elem. phys., vol. ii. p. 134.
(4) On suspended respiration from drowning, hanging , and suffocation, London, 1791.
(5) Loc. cit., p. 133.
(6) System of human anat., vol. i. p. 38.
(7) Hamberger, Physiologie , p. 708.
(8) Mem. de Paris, 1770, p. 245.
(9) Loc. cit.
(10) Did. des sc. méd. vol. v. p. 440.
ANGEIOLOGY.
197
as 6 : 5, Brown Langrish as 11 : 10.(1) Gordon lias found the two
ventricles nearly equal in some cases, (2) and Portal asserts that their
capacity is the same in young people. (3)
These differences in the estimates of authors furnish a new argument against the common opinion, since we should presume that they depend on greater or less accidental obstacles to the pulmonary circulation.
We cannot however deny but that the capacitj^ of the right portion of the heart is a little greater than that of the left, because the blood brought by the vena cava has received the fluid contained in the thoracic canal. It is also proved by the difference relative to the age in the degree of disproportion, this being, directly after birth, less than at a more advanced period of life. (4)
Legallois has also found the right portion of the heart a little broader than the left in every kind of death, both after strangulation and from the loss of blood.(5) The facts related prove only that the right portion of the heart can contract as much as, and even more than the left, in certain circumstances, and that the left is also susceptible of becoming larger than the light, but not that the capacity of the latter exceeds that of the former during life.
4th. The fibres of the right side, especially those of the ventricle, are not arranged in the same manner as those of the left side.
a. The thinness of the right ventricle is attended also with fewer fibrous layers, a fact already pointed out by Senac,(6) but which Wolff has indicated more precisely in saying that the right ventricle is formed of three layers only, while that of the left side presents six, counting the fleshy fasciculi of its internal face. (7) We have not however been able to find this number of laj'ers. Usually we have observed on each side only three distinct layers, two oblique, and one internal longitudinal.
b. The fibres of the right ventricle are flatter and thinner than those of the left. Thus the former form flattened fasciculi, and the second rounded and thicker fasciculi. The latter ramify more ; they are separated by fat, and have spaces between them, while we can hardly distinguish the former from each other except by the direction of their fibres.
e. The fibres of the right ventricle are more oblique and annular, while those of the left are more longitudinal.
d. The layers of the right ventricle, although thinner, are much more distinct than those of the left ventricle ; besides the latter are still
(1) De part.corp hum. fabric., vol. ii. p. 133.
(2) Loc. cit., p. 33.
(3) Doc. cit.
(4) Portal, loc. cit.
(5) TV. du cœur, vol. i. p. 200.
(6) De stratis ßbrarum cordis in Universum, in the Nov. act. Petrop. vol. iii. an 1785, p. 234-238.
(7) Loc. cit., p. 234.
198
DESCRIPTIVE ANATOMY.
more similar in regard to direction, which doubtless contributes to make
the left ventricle firmer, bat proves at the same time that we should
exercise some judgment in determining the number and direction of
these layers. Such at least is the positive result of our researches.
This also is the opinion of Wolff himself, who has studied the arrangement of the heart with too much exactness.
5th. The primitive form of the heart, that of a canal curved on itself, is more evident in the left ventricle than in the right.
6th. The nerves of the left side are larger and more numerous than those of the right side.
CHAPTER II.
SPECIAL REMARKS ON THE HEART.
§ 1304. We usually describe first the right half of the heart ; and in order to follow the direction of the circulation of the blood, we begin with the right auricle.
I. RIGHT AURICLE.
§ 1305. The right auricle ( atrium anterius , s. venarum car arum , s. der truin'), forms that portion of the base of the heart situated farthest on the right and forward.
Its form is almost square ; the vena cava superior descends obliquely from right to left, and from behind forward, towards its upper and right angle, and the vena cava inferior ascends in a contrary direction towards its lower and right angle. Notwithstanding this difference in the direction of the two venæ cavæ, we must admit that they unite and form a single trunk in the cavity of the auricle, for they unite on the right forward and backward, and the absence of the left side of their circumference is only apparent, since this side in fact exists, but is dilated to produce the muscular part of the auricle. The upper and left angle of the latter extends into a small blunt appendage, formed like a rounded square, which is observed before the lower paît of the aorta. The lower and left angle is rounded.
We observe transverse fibres on all the circumference of this auricle, directly below the inner membrane of the heart, which, becoming thinner and separating from each other above and below, are prolonged for a small distance around the superior and inferior venæ cavæ. They are thinner where they surround the point of union of the two venæ cavæ forward, and are extended more uniformly, and are smoother on the right side, both on thsir outer and on their inner face.
But the left part of the posterior face of the anterior and unattached wall of the right auricle, which is the most extensive, is uneven internally. This unevenness depends on much larger and transverse fasci
ANGEIOLOGY.
199
culi, which are united by other smaller oblique fasciculi, so as to present a reticulated appearance. These fasciculi, with which the transverse fibres of the auricle are united, appear between two longitudinal
smooth bands which proceed only along its internal face. One of
these tw'o bands, the left, descends a short distance from the anterior
part of the venous orifice of the left ventricle ; the other, the right,
situated almost in the centre of the anterior wall, a little however to
the right, descends toward the left side, along the union of the two
venæ cavæ. These fleshy fasciculi have been called the pectinœal
muscles (AT. pectinati ) .
The posterior wall of the right auricle forms the anterior face of the interventricular septum. We discover in it several remarkable parts, some of which belong to the history of the development of the heart.
On the right side and toward the centre is the fossa ovalis ( fossa ovalis , s. valvula foraminis ovalis, s. vestigium foraminis ovalis), an oblong and rounded depression, which varies much in size. This fossa is very distinct from the posterior wall of the auricle at its upper part, a little less so on its sides, especially on the right, and is generally blended with it below, particularly on the right side. The more extensive it is, the less evident are the limits which separate it from the other parts of the posterior wall. It however not unfrequently presents a similar arrangement even when it is very small.
Most generally it exactly fills the space between the edges of the projection which surrounds it, and it is very tense, but not unfrequently it is much larger, and forms a valve, the loose edge of which corresponds to the left auricle. We almost always observe a greater or less depression above, between its extremity and the upper part of the projection which surrounds it. Very often also we see in this place one or more openings by which the cavity of the two auricles communicate. This arrangement is not constant, and it is entirely independent of the extent either of the valve or of the depression, although it occurs particularly when the valve is very broad. Even when the openings are large and numerous, they seldom descend below the central part of the projection which surrounds the depression, so that the septum of the auricles is complete in regard to the separation of the blood contained in the two cavities.
This place, especially in its upper part, is the thinnest portion of the septum and of the auricle generally. W T e however always observe muscular fibres between the two layers of the internal membrane of the heart, that of the right and that of the left auricle.
The projection which surrounds this depression is formed of reticulated muscular fibres. It is called the ring or the isthmus of Vieussens ( annulus , s. isthmus Vieussenii). Its right portion separates the right and left halves of the septum. Although it does not project at its lower part, it is however complete in this place also.
We observe in its circumference several openings of the cardiac veins, called the foramina of Thebesius ( foramina Thebesii). At the
200
DESCRIPTIVE ANATOMY.
lower end of the inferior edge of the ring a circular fold of the inner
membrane of the right auricle commences, this is called the Eustachian
valve ) or the anterior valve of the foramen ovale ( valvula Eustachii , s.
foraminis ovalis anterior). { 1) This fold extends more or less to the
right, along the anterior part of the orifice of the vena cava ascendens
into the right auricle, so that its lower edge is concave and attached
while the upper is convex and loose within the right auricle. It imperfectly separates below the right and left halves of the right auricle.
This valve varies much in regard to size, form, and texture. It is usually more perfect and proportionally larger in the fetus than at any time after birth. In the adult it is often entirely changed, at least at its upper part, into a reticular tissue, and in many cases some filaments only trace the valve, and these frequently do not exist. It usually contains some muscular fibres, but it is often only a simple fold of the internal membrane.
An intimate relation generally exists between the Eustachian valve and the fossa ovalis, the former being more developed in proportion as the septum formed by the latter between the two auricles is less perfect, and vice versa ; but to this rule there are numerous exceptions.
The valve acts principally in the fetus. At this period of life it conducts the blood of the vena cava superior toward the opening of the septum or the foramen ovale. Hence the relation between it and the valve of this opening.
In the adult it may prevent to a slight degree the reflux of the blood from the vena cava superior, and from the right auricle generally into the vena cava inferior. Directly at the left side of the left branch of the isthmus of Vieussens, between this branch and the venous orifice of the right ventricle, there is a large and rounded opening, the orifiee of the large coronary vein of the heart ( orificium venae coronariœ cordis magnœ).{ 2) This opening is sometimes divided more or less distinctly into several, and generally is more or less perfectly closed by a valvular fold, which arises at its lower part. This fold, called the valve of Thebesius ( valvula Thebesii), has its upper and .concave edge unattached, while its lower and convex edge adheres. Sometimes it does not exist in other cases it is replaced by one or more imperfect transverse bands ; finally, in some subjects there are several, even as many as six, situated one behind another.
(1) Winslow, Description d'une valvule singulière de la veine cave inferieure , à l'occasion de laquelle on propose un sentiment nouveau sur la fameuse question du, trou ovale , in the Mém. de Paris -, 1717, p. 272. Eclaircissement sur un Mèm.de 1-717, Ibid. 1725. — Haller, De valvulâ Euslacliii, Gottingen, 1737. — L. Crell, De valvulâ venœ cavœ Eustachianä, Wittenberg-, 1737.- — Brencle), De valvulâ Eustachianâ inter venam inferiorem dextramque cordis auriculam positâ, Wittenberg, 1738. — Haller, De valvulâ Eustachii prog.r. ii. Gottingen, 1748. — J. M. Diebolt, De foramine ovali, Strasburg, 1771. — J. F. Lobstein, De valvulâ Eustachii , Strasburg, 1771. — C. F. Wolff, De foramine ovali cjusque usu in dirigendo sanguinis motu observationes novœ, in the N. C. Pctrop, vol. xx. p. 357. — H. L. Leveling, De valvulâ Eustachii et foramine ovali, in the Obs. anal, rar f asc. i. 1786.
(2) Wolff, De orificio venœ coronariœ magnee ; in the Act. P elrop. 1777, p. 234-257.
ANCEIOLOGY.
201
II. RIGHT VENTRICLE.
§ 1306. The anterior , pulmonary, or right ventricle ( ventriculus anterior, s. dexter , s. pulmonalis ) is composed of an upper and lower portion, which are separated bj the upper part of the venous valve. The former unites directly to the right auricle, the latter to the pulmonary artery, and its walls are thinner than those of the former. It terminates in a conical extremity, which projects upward and backward above the left ventricle and the septum of the heart. The pulmonary artery arises from this part.
The internal or posterior wall is formed by the septum of the heart and is slightly convex ; the anterior is still more so. The posterior wall is smoother than the anterior at its upper portion and very often entirely so below the arterial opening. The net-woik formed by the projecting muscular fasciculi is much more complete toward its summit than toward its base.
The anterior wall of the pulmonary ventricle is thinnest above toward the septum and thickest below also near the septum. Its thickness when the heart is strong and not very much distended is more than two lines, but less than this in the latter point. The two parts are scarcely a line thick even in those hearts which are neither very much distended nor small.
The quantity of blood in the right ventricle after death varies from one ounce and a half to three ounces.
§ 1307. The venous valve of the right auricle arises from the circumference of its venous orifice. It is called the tricuspid valve ( val vida triglochis , tricuspis ), because, although it forms a single membrane, it is higher in three points than in the short spaces between them, and thus three slips are formed.
Of these, one, which is the largest, arises from the external and anterior part of the circumference of the venous orifice. The other two are smaller and arise from the inner and posterior part of this circumference, one over the other ; so that consequently there is an external and larger slip, and two internal, an upper and a lower slip.
The last two are separated from each other by a space not so deep as those between them and the external. It is then more correct to admit only two slips, an anterior and external and a posterior and internal.
The first is much higher than the second.
The tendinous filaments of the upper extremity of the anterior or external slip are attached to this upper part of the septum. They are few in number. We usually find in the space only one or at most two short muscles, to which are attached those filaments farthest to the left ; the others are inserted in its smooth wall. Most of those filaments which come from the central and lower parts of the edge of
VOL. II.
26
202
DESCRIPTIVE ANATOMY.
this slip are attached to the summits of five or six of the fleshy pillars
coming from the middle and lower parts of the anterior wall.
The filaments which arise from the posterior slips are mostly attached to the smooth folds of the septum, except a few, which are inserted in two or three small fleshy pillars, all of which except the lowest come from the septum.
The arterial orifice generally extends about three fourths of an inch higher than the venous. The sigmoid valves are thin. Their tubercles ( noduli Morgagnii ) are slight swellings, which however are often well marked in the young fetus.
III. LEFT AURICLE.
§ 1308 . The left, posterior, or pulmonary auricle (atrium sinistrum , s. posterius, s. venarum puhnonalium, s. aorticum) is of an oblong square form, considerably more broad than high.
It is separated below and posteriorly from the left ventricle by a circular groove, upward and to the right from the right ventricle by a similar depression. The pulmonary artery, the aorta, and the vena cava superior are also found upward and outward, between it and the right ventricle ; so that the external part of its right and left extremities is alone visible.
Its upper left angle rises into an auricular appendage ( auricula sinis tra ), which goes forward to the left and upward, directly behind the pulmonary artery, separating very much from the rest of the auricle. This appendage, which is narrower, longer, and on the whole larger than that of the right auricle, is circumscribed by rougher edges. It curves three or four times and finally terminates in a sharp summit, below and before the pulmonary artery.
The posterior wall of the lower part, the sinus of the auricle (sinus venarum puhnonalium), receives where it is continuous with the lateral parietes the four pulmonary veins, two on each side, the upper being larger than the lower. One of the two veins of the same side opens directly above the other, while between those of the two opposite sides is the whole breadth of the auricle ; so that the two pairs occupy the whole height of the posterior wall.
The parietes of the whole auricle are muscular and formed principally of transverse fibres. They are smooth with the exception of the appendage. We observe in its whole length an anterior and a posterior series of very prominent transverse fasciculi, united by other smaller and oblique fasciculi, which proceed between two longitudinal bands, situated one on the right the other on the left.
The anterior wall is formed by the septum of the auricles and is also, like the posterior face of the septum, irregular in another respect. In fact we there observe a constant semicircular valve, which is however more or less developed. This valve leaves the upper edge of the transparent point which corresponds to the fossa ovalis of the right auricle (§ 1305 ). It is turned upward and toward the left. Its lower edge
ANGEIOLOGY.
203
is convex and attached, and its upper edge is loose in a greater or less
extent. Sometimes there is only a slight projection in its place.
This valve extends behind the interauricular septum. Its lower edge is attached to the posterior face of the centre of the isthmus of Vieussens, and the space between it and this isthmus forms a small cavity ( sinus septi ), which terminates below in a cul-de-sac. This is only the upper part of the valve of the foramen ovale (§ 1305), which in the normal state always ascends on the posterior face of the isthmus. Of this we are readily convinced when it does not adhere to the isthmus in the centre ; for then the continuity is totally uninterrupted.
IV. LEFT VENTRICLE.
§ 1309. The left ventricle (venir i cuius sinister ) posterior, s. aorticus ) is the strongest of all parts of the heart and forms its figure. Its posterior wall and its anterior wall which forms the posterior face of the septum, are convex externally and concave internally : so that its whole form is oval. The internal face of the posterior wall is very much reticulated ; the anterior wall is smooth at its upper part and reticulated in the lower, but less so than the posterior wall. The fleshy pillars are rounded.
The thickness of the parietes is less toward the summit and greater at the base than in all other parts. In the adult it is five or six lines thick at the base and only three at the summit.
The capacity of the left ventricle varies in the adult from eight to twenty drachms.
§ 1310. Before the round venous orifice we find the mitral valve ( valvula mitralis), composed of an upper and a lower slip. The upper arises directly below or rather before the ring of the sigmoid valve of the aorta, and is attached by slips to three or four fleshy pillars, which all come from the internal face of the posterior wall of the ventricle, some above, others below, and among which we distinguish two particularly, an upper and a lower, which are much larger than the others. The inferior and external slip, which is much narrower, is attached by tendinous filaments to a short but very thick fleshy pillar.
All these fleshy pillars arise from the posterior wall of the left ventricle ; so that those of the upper slip arise near the summit of the heart, and cover those of the lower, so that we cannot perceive the lower slip until we have removed the upper or have detached it from its fleshy pillars.
The orifice of the artery is situated directly over that of the vein. Its sigmoid valves are thick and are generally supplied with tubercles ( noduli Arantii ), which are very distinct.
204
DESCRIPTIVE ANATOMY.
V. SEPTUM.
§ 1311,. In the normal state the septum of the heart completely separates its two halves, even when the valve of the foramen ovale is not united with the isthmus of Yieussens at its upper part. In the venous portion of the heart it is much thinner than the auricles, which it separates, and is much lower, as they project above it. It is not muscular in every part, and generally there are no muscular fibres in the upper part, of the old valve of the foramen ovale.
In the arterial portion, on the contrary, the septum is very muscular and is formed almost entirely by the fibres of the left ventricle. It projects considerably into the right ventricle, while in its posterior face, which forms the anterior wall of the left ventricle, there is a deep depression. Its height equals that of the ventricles. It is triangular and terminates in a point toward the summit of the heart. It is generally from four to five lines thick, and even more than a half an inch thick in those parts where the large fascicidi project above the surface in those subjects which have large hearts. It is thickest below the orifices of the large arterial trunks, and thinnest beyond this point toward the interauricular septum. It is almost always weaker at the summit, where the layers which constitute it are less compact and more easily separated from each other,
CHAPTER III
OF THE PERICARDIUM.
§ 1312. The pericardium (pericardium) (§ 1 293) ( 1 ) is a fibro-serous membrane (§ 354), which entirely envelops the heart and the origin of the large vessels, and unites them with the adjacent parts.
The fibres which strengthen its outer layer and which are very apparent in old men, arise from the central aponeurosis of the diaphragm and extend longitudinally over the serous membrane. They are very much developed, particularly forward and upward.
Its lower face, w’hich corresponds to the lower and flat face of the heart, is intimately united to the upper face of the central aponeurosis of the diaphragm by a very short cellular tissue.
It is covered on the sides and forward by the inner walls of the pleuræ.
Behind, it is attached to the esophagus and to the root of the right lung.
(1) J. M. Hoffmann, Diss. de pericardio, Altdorf, 1690. — A. B. Heimann, De pericardio sano et morboso, Leyden, 1729. — Lanzoni, De pericardio ; in Opp. omn., Lausanne, 1738.
ANGEIOLOGY.
205
§ 1313. The pericardium incloses not merely the heart but also the
origins of the large vessels, whence it is reflected on itself in every
direction to arrive at the centre of the heart.
When examined from before backward and from above downward, we notice the following arrangement :
It envelops the aorta and the trunk of the pulmonary artery forward for about two and a half inches, unites these two vessels very closely, and passes uninterruptedly from one to the other ; so that the corresponding parts of their circumference are retained by a cellular tissue.
The posterior part of these vessels is not covered in the same extent by the pericardium.
From the aorta this membrane passes to the right on the vena cava superior, to about an inch above its entrance into the right auricle, descends obliquely from left to right on its anterior portion, then arrives at the right pulmonary veins, on which it descends to about half an inch from their entrance into the left auricle, then goes on the anterior part of the vena cava inferior, directly below its opening into the right auricle, and wholly surrounds it except a small part of its posterior portion. Thence it goes to the left, on all the surface of the left pulmonary veins, and finally covers the left branch of the pulmonary artery below.
From all these parts the pericardium is reflected on itself. It adheres feebly to the large vessels, but much more strongly to the auricles and ventricles.
As in all other serous membranes, the inner and reflected portion of the pericardium is thinner than the external. It closely envelops thesurface of the parts inclosed by the membranous sac, and, except in those parts where it is reflected, it is entirely separated from the outer layer, although they touch ; so that the circumference of the heart is perfectly loose and is attached only by its upper part.
CHAPTER IV.
OF THE DIFFERENCES OF THE HEART WHICH DEPEND ON THE DEVELOPMENT AND ON THE SEX.
§ 1314, The differences presented by the heart in regard to its development are considerable.(l) They relate to its volume , situation , form , and texture.
1st. Volume. The heart is much larger in proportion to the body in the early periods of life than at a more advanced period. The relation
(1) The principal works on this subject are mentioned in Danz, Grundriss der Zergliederungskunde des ungebornen Kindes in den verschiedenen Zeilen der Schwangerschaft, vol. ii. Giessen, 1793, p. 185-188. — See also Meckel, Mémoire sur le développement du cœur ; in the Journal complémentaire , vol. i. p. 259. — Rolando, Memoire sur la formation du cœur ; same journal, vol. xv. p. 323, vol. xvi. p. 34.
208
DESCRIPTIVE ANATOMY.
between it and the body is as 1 : 120 in the full grown fetus and in
the early years of life, while before this period, in the second and third
month of pregnancy, it is as 1 : 50.
2d. Situation. At first the heart is not oblique, but its summit looks directly forward and a little downward. It is only at the fourth month that it begins to turn slightly toward the left side.
3d. Form. The differences in its form are the most important and relate both to the circumference of the whole organ and to the mode of limiting its cavities. Observers have not decided whether there is or is not in the human fetus a period very near its origin, when the heart forms only a single cavity, composed of several compartments placed near each other. But if this period exists, it passes rapidly, since all the external parts are developed in the fetus at the end of one month.
A. OUTER CIRCUMFERENCE.
a. At first the arterial portion of the heart is much smaller in proportion to the venous. The right auricle especially remains for a long time the largest portion of this organ. The permanent relation however begins to establish itself during the last half of uterine existence.
b. The arterial portion is at first flat and rounded : soon however its breadth exceeds its length. Its summit is at first single and blunt ; but as it enlarges it bifurcates. This phenomenon depends on the fact that the right ventricle from its situation does not at first concur to form the summit of the heart ; but it gradually extends downward and remains separated from the left ventricle by a considerable depression. This groove sometimes continues during life, but almost always disappears after the middle of uterine existence.
c. The right ventricle is at first much smaller than the left : they are soon equal in size : for a certain time the right ventricle is even a little larger, but it becomes smaller during most of uterine existence ; so that it is narrower in the full grown fetus and in the young child. The greater size of the right ventricle seems to result from the obstacles which often disturb the pulmonary circulation at an advanced period of life.(l)
(1) This at least has been observed by Portal ( Sur la capacité des ventricules du
cœur ; in the Mem. de. Paris, 1770, p. 244-246). In the heart of a full grown fetus
the left ventricle contained seven drachms of water, while the right contained only
six and a half. The capacity of the two ventricles was the same in that of a young
child ; in that of an adult the right ventricle contained eighteen drachms of water,
and the left only seventeen. The experiments of Legallois (Diet, des sc. méd., vol. v.
p. 440,) prove that we can introduce
In an adult,
In a child,
grs. of mercury
5 Into the right ventricle, 1172 ( Into the left ventricle 1068
f Into the right ventricle, 828 ! Into the left, not softened I by pressure, - - 658
1 Into the left, softened, 822
ANGEIOLOGY.
207
d. In the early periods of life the upper and pyramidal extremity of
the upper part of the pulmonary ventricle is less distinct from the rest
of the organ than at more advanced periods : it elevates itself also less
above the left ventricle and the septum. This peculiarity is very curious, as precisely the contrary is seen in many mammalia, especially
the ruminantia and the hog.
B. INTERNAL ARRANGEMENT OF THE HEART.
The principal difference presented by the heart in this respect is, that
its septum is imperfect in the early periods of life, whence its right and
left portions then communicate with each other.
a. The interauricular septum is perforated during all fetal existence by an opening called the foramen ovale. This foramen is much greater as the fetus is younger ; so that we may consider the septum as primitively deficient and the two auricles then form a single cavity. The foramen ovale gradually grows smaller and occupies the lower and central part of the septum. The Eustachian valve is found very early directly before it and on the right, so as to occupy all its height. Hence as it arises from the anterior part of the circumference of the vena cava inferior, it separates the right and left auricle in such a manner, that this vein empties directly into the left auricle only. On the contrary, there is no trace of the closing of the foramen ovale on the left side till the commencement of the third month. But about this period this foramen begins to be obliterated by the formation of its valve, which arises from the posterior part of the vena cava.
In a still-born child,
In a seven months’ fetus,
In another about the same age,
grs. of mercury
( Into the right ventricle, 34 ! Into the left ventricle,
I not softened, - - 37
^ Into the left, softened, - 78
Into the right ventricle, 23
Into the left, not softened nor flaccid, - - 34
Into the right ventricle, 21
Into the left, softened, 54
In repeating these experiments, also with mercury, we have obtained the following
results :
In a man 50 years old, In a woman 46 years old,
In a woman 40 years old,
In a man 34 years old, “ 30 “ “ 26 “ - In a boy 16 “ - In a girl 7 months old, In a new born boy which had breathed, In a still-born boy,
R. ventricle
L. ventricle
L. auricle
R auricle
oz. drs.
oz. drs.
oz. drs.
oz. drs.
30
10
25
20
40
22 4
22
15
55
40
41
35
32
15 4
21
25
32 4
28 4
25
22 4
28
20 4
20
18
41 4
21 4
37
29
2 4
1 4
1 4
1 6
1 6
2
1 6
1 2
1 4
2
together 4 ounces.
208
DESCRIPTIVE ANATOMY.
As this enlarges, the Eustachian valve diminishes and recedes from
the septum, while on the contrary that of the foramen ovale approaches
it. The latter also becomes narrower and more tense, especially in the
latter months of pregnancy ; so that it closes the opening more exactly.
The termination of the vena cava inferior in the heart suddenly changes,
and this vessel empties itself no longer into the left auricle but into the
right. This change is also favored by that which takes place in the
situation of the heart, which varies so that its summit corresponds
to the left ; the right auricle is more than usually elevated above the
vena cava inferior, at the same time that the Eustachian valve is removed from the septum and is carried forward.
The valve of the foramen ovale increases from below upward along the lateral edges of this foramen. At the sixth month of pregnancy it has already arrived at its upper part ; it then passes beyond it ; so that â– the interauricular septum is entirely filled, except a small space, which is no longer an opening but a very short canal, formed forward by the upper part of the ring of the foramen ovale and backward by the upper part of the valve.
b. It is not yet well demonstrated whether the ventricles, like the auricles, form at first only a single cavity without a septum, although the development of the heart in the animal series, and the deviations of formation of this organ lead us to this opinion. We have always found a trace of the interauricular septum at the summit of the heart, even in the youngest fetuses we could examine. During the first two months however, or at least till the middle of the second, this septum presents at its upper part a foramen, at first rather large, but it gradually diminishes, and is found below the origin of the large vessels, so that the two ventricles form only one, which is imperfectly divided into two portions. This opening is obliterated at the period when the artery which arises from the ventricles becomes double, instead of single, as it was at first ; that is, when the pulmonary artery, which before was blended with the aorta, becomes a proper and distinct vessel. Its obliteration then much precedes that of the foramen ovale.
4th. Texture. The thickness of the parietes is much greater compared to the size of the cavities during the early periods of life than subsequently, and the greatest size of the heart then depends on this cause.(l)
The parietes on both sides are then equally thick. The difference which always exists afterwards, and which is scarcely perceptible even in a full grown fetus, does not begin to be developed till the second half of uterine existence.
The fibrous texture and the different layers of fibres are always more apparent at the early periods of life than at a more advanced age.
(1) Gordon is mistaken in saying- that the parietes of the heart are proportionally thinner in the early periods of life than at a more remote period ( System of human anatomy , vol. i. p. 53.)
ANGEJOLOGV.
209
5th. Color. The color of the heart is much blighter when the
subject is younger.
No fat has as yet accumulated on the surface of this organ in the early periods of fetal existence ; but this is generally the case with all parts of the body.
The pericardium is then proportionally thicker than at subsequent periods, and its internal or reflected layer adheres less intimately to the heart.
C. SEXUAL DIFFERENCES,
§ 1315. The only sexual difference seen in the heart is that it is proportionally a little larger in males.
CHAPTER V.
MOTIONS OF THE HEART,
§ 1316. The circumstances in the history of the motions of the heart, or in the heart in its active state, which deserve examination, are,
1st. The changes in its form.
2d. The succession and simultaneousness of the motions in its different parts.
3d. The relation between the cavities of the heart in its different states and the blood.
4th. The number of its motions.
5th. The changes in its situation.
6th. The duration of its motions.
7th. The conditions on which they depend.
§ 1317. 1st. The heart diminishes in contraction and enlarges in dilatation in every directional )
2d. The auricles and ventricles contract and dilate alternately, so that the two auricles and the two ventricles execute the same motions at the same time. (2) The auricles in contracting send the blood into
(1) Sur le changement du figure de cœur dans le style , in the Mêm. de Paris, 1731, hist. p. 33, 40.
(2) The motions of the heart have been carefully analyzed by Laennec with the aid of the stethoscope, by which we can study them more correctly than by opening and inspecting living animals {De l'auscultation médiate, vol. ii. p. 195-227). From this analysis are deduced numerous important practical facts.
In the motions of the heart we must consider their extent, its impulse, the nature, and intensity of the sound and the rythm, according to which the different parts of the organ contract.
1st. Extent. In a healthy and moderately fleshy subject, the pulsations of the heart are heard only in the space between the cartilages of the fifth and sixth true ribs, and under the lower part of the sternum. Those of the left cavities correspond principally to the first point, and those of the right to the second. If the sternum is short, we hear the pulsations in the epigastrium also. When the subject is so fat that
Vol. IT. 27
210
DESCRIPTIVE ANATOMY.
the ventricles, which then contract on it, and throw it into the arteries
at their base. A small quantity of the fluid however always returns
Irom the arteries into the ventricles, from these into the auricles, and
thence into the veins which open into them.
3d. The cavities of the heart are almost entirely empty when they contract. However a little blood always remains, which is attached especially to the reticulated surface of their inner face.
4th. When the ventricles contract the apex of the heart beats against the anterior wall of the chest, notwithstanding that the organ shortens. This arises principally because that the auricles are then filled, both by the blood disgorged by the veins and by that which
they cannot be felt by the hand, the space in which they can be heard by the stethoscope' is sometimes only about a square inch. In thin persons, when the chest is narrow, and even in children, they always have more extent. They may be heard in the lower third, or even in the three lower fourths, of the sternum; sometimes also, under all this bone, at the left anterior and upper part of the chest to near the clavicle, and sometimes, but less manifestly, under the right clavicle. The subject rarely enjoys perfect health when the extent of the pulsations exceeds these limits, so that they are hoard in the left side of the chest, from the axilla to the region corresponding to the stomach ; and to a similar extent on the right side, at the left posterior part of the chest ; finally, on the right posterior part, a successive progress, which would seem to be constant, and which is attended with a progressive diminution in the intensity of the sound. In this respect w r c may state as a principle, that the extent of the heart’s pulsations is directly as the feebleness and the thinness of its parietes, especially those of the auricles, and inversely as their force and thickness.
_ 2d. Impulse of the heart. In contracting, the heart gives a sensation of percussion, raising or repelling the hand, or any other part placed upon the anterior walls of the thorax. In some individuals this impulse is visible, and sometimes causes a very extensive motion, which raises the parietes of the chest, the epigastric region, and even the clothing. It is however but slightly marked when the proportions of the heart are normal, and is often imperceptible in fat people. It is perceptible only during the systole of the ventricles. If the contraction of the auricles sometimes produces a similar phenomenon, it may be distinguished from the first, inasmuch as most generally it consists only in a kind of rumbling, which is heard very deeply in the mediastium. This impulse is generally perceptible only between the cartilages of the fifth and sixth true ribs, or, at most, in the lower half of the sternum, and in some subjects, when the sternum is very short, in the epigastrium. Generally speaking, it is inversely as the extent of the pulsations, and directly, as the thickness of the ventricles.
3d. Nature of the sound. On listening attentively we distinguish during the pulsations of the heart two distinct sounds : one, duller and continued ; the other, quicker, and more distinct. The first is simultaneous with the pulsations of the arteries and marks the contraction of the ventricles; the second is caused by the contractions of the auricles. That heard at the lower part of the sternum belongs to the right cavities; that distinguished between the cartilages of;the fifth and sixth ribs depends on the left cavities. In the normal state, this noise is similar and equal on both sides; and is no where so loud as in the precordial region. It is as much stronger as the parietes of the ventricles are thinner, and as the power of impulse of the heart is less.
4th. Rythm. The duration of the sound caused by the auricles is shorter than of that produced by the ventricles ; hence, the contractions of the auricles do not continue as long as those of the ventricles. There is a well marked but short interval of rest between these two sounds. This observation proves that the heart, like all other muscles, is alternately in a state of action and of rest. We may admit, that of the twenty-four hours, the ventricles have twelve and the auricles eighteen hours of rest ; i n supposing also that the cavities of the heart arc entirely passive in their dilatation. In fact, Laennec admits that in the most general state of the whole duration of time in which the successive contractions of different parts of the heart, occur, a third at most, or even a quarter, is occupied by the systole of the auricles ; a fourth, or a little less, by absolute rest, and a little more than a half by the systole of the ventricles. F. T.
ANGEIOLOGY.
211
flows back from the ventricles, so that the latter are pushed forward :
but it depends also a little on the extension of the arterial trunks at the
moment when the arterial blood which is sent from the ventricles
passes through them.(l) From not attending to these last two circumstances it was for a long time impossible to explain the pulsations
of the heart during* its contractions, except by admitting that it lengthened in performing this motion, which is very improbable.
5th. The mean number of pulsations of the heart in the adult is seventy per minute. But it varies much according to the individual. The pulsations are generally more feeble and fewer in the female. If we except the early periods of life when the contractions of the heart are few, the number of its pulsations is much greater the nearer it is to the period of its formation.
6th. We generally consider the heart as that part in which irritatability continues the longest. But it follows from the observations of Haller, Zimmerman, and Oeder, that there are exceptions to this law ; and the observations of Fontana, Crève, (2) and Nysten,(3) with which our own agree, demonstrate that this is not true, at least to the arterial portion, since the ventricles lose their irritability before the other muscular parts of the body ; but the auricles preserve it the longest, (4) and that the right auricle remains irritable longer than the left. Haller has attempted to prove that this latter difference depends on the circumstance that the right auricle is stimulated longer by the blood within it, (5) but we have often seen it in hearts which were removed from the chest and totally destitute of blood. Nysten Iras observed it also in persons who were beheaded. We then have reason to say it depends on the greater tenacity of life in this part of the heart, and the more as the tenacity increases in animals in a direct ratio with the predominance of the venous system in them,
7th. The conditions of the action of the heart are the same as those of muscular action generally. For this then we refer to the details already mentioned in the first volume.
(1) When the ventricles contract, the point of the heart strikes the left lateral wall
of the chest, between the cartilages of the fifth and sixth ribs. The two causes mentioned by the author, the filling of the auricles and the extension of the trunks of the arteries, doubtless contribute to produce this phenomenon; but we may admit also that while the ventricles contract, their moveable point rises, and performs the motion of a pendulum on the base of the heart, which, being more fixed, serves as a point of support. F. T.
(2) Vom Metallreize , Leipsic, 1796, p. 100.
(3) Recherches dephysiol, et de chimie , Paris, 1811, p. 307.
(4) As Davy observed in experiments for another purpose. See his Researches on nitrous oxide, London, 1800, p. 352.
(5) De cordis m,otu a stimido i\ato, in the Comm. Gott., vol. i,
CHAPTER VI.
OP THE HEART IN THE ABNORMAL STATE.
§ 1318. The anomalies of the heart are divided into two sections, according as they affect the form or the texture of this organ. We shall mention here only the first, having spoken of the latter in the first volume, when treating of the alterations in the texture of the vessels, of the muscles, and of the serous membranes.
§ 1319. The deviations in the formation of the heart embrace anomalies which may exist in number, situation, volume, and figure.
§ 1320. In regard to number, the heart may vary from the normal state in two opposite modes, that is, may be either wholly or partially deficient, or may have supernumerary parts.
The heart is entirely absent only when the upper half of the body is very imperfectly developed, and the head is then usually deficient. However, this rule presents but rarely exceptions of two kinds : for, first, the heart sometimes appears when the head does not exist ;(1) and secondly, this organ is sometimes wholly(2) or partly deficient(3) in monsters where the trunk and head are not very much deformed. We shall speak of the partial absence of the heart hereafter.
The plurality of the heart, the body being simple, is infinitely more rare, however common it may be when the body is double, but is not seen constantly even in the latter case. We know of but one instance of a perfect plurality of the heart where the body was single. We are led to this anomaly by the fissure of the ventricles and by the congenital existence of abnormal and hollow appendages to the heart. (4)
§ 1321. The anomalies in the situation of the heart are congenital or accidental. In the first case the organ exists sometimes within, and sometimes outside of the cavity of the thorax.
When found in the chest it may be,
1st. Straight, and then either perpendicular, or horizontal, or finally placed so that its summit looks upward.(5)
2d. Reversed, having its base to the left and its summit to the right, an anomaly which exists singly or which is attended with the more or less perfect inversion of the other organs. (6)
(1) We have collected all the instances of this anomaly in our Handbuch der pathologischen Anatomie, vol. i. p. 165.
(2) See our Handbuch der path. Anat,, vol. i. p. 414. Besides the cases there mentioned, two have been published since; one by Brodie {Phil. Trans. 1811), and the other by Lawrence {Méd. Chir. Trans.), vol. v.
(3) Rœderer, in the Comment. Gott., vol. iv. — Meckel, Handb. der path. Anat., vol. i. p. 421.
(4) We have collected all the cases of this anomaly in Meckel, De duplic. monstrosa, p. 53, and Handb. der path. Anat., vol. ii. p. 33-45.
(5) Meckel, Handb. der path. Anat; vol. i. p. 418. — Bertin in his work has figured a heart which was situated transversely in the cavity of the thorax.
(6) One case of this kind now before us has been figured in Meckel, De conditionibus cordis abnorm ., Halle, 1802, vol. i.
ANGEIOLOGV.
213
3d . Deeper than usual. ( 1 )
When it exists out of the chest two cases are possible.
1st. The anomaly being slight the heart hangs loosely outward, either in its usual place(2) or higher than it is generally, in the cervical iegion.(3) In this case the pericardium is usually but not always deficient. On the other hand it sometimes but very rarely happens that this membrane is not found even when the heart is situated in the chest, and then it is replaced by the pleura. (4)
2d. The anomaly existing in a greater degree which is also still more rare, the heart is found in the abdomen, (5) a deviation of formation to which the very sloping situation of this organ in the pectoral cavity leads.
The accidental anomalies in the situation of the heart depend on the accumulation of solids or liquids within the chest or the penetration of foreign bodies there, and follow no constant and fixed laws.
§ 1322. Anomalies in the volume of the heart are congenital much less frequently than accidental. They however sometimes have the character of a primitive formation, and are even hereditary in many families. The heart is then too small or too large. We often find both of these anomalies in the different parts of the same heart.
The smallness of the heart(6) is much more rare than its excess in volume. It is often carried to an extreme point although the formation of the organ is unchanged. (7)
As to the excessive size of the heart, we must distinguish the pure and simple increase in its mass, the thickening of its parietes,(8) from the thickening of its parietes with an increase in its capacity, (9) and from its simple dilatation or an increase in its capacity(lO) with or without a thinness of its parietes, since we find all these states sometimes insu (1) Meckel, Handb. der path. Anat., vol. i. p. 417.
(2) Id. Ibid. vol. i. p. 406.
(3) Id. Ibid. vol. i. p. 98, 99.
(4) See our Handb. der path. Anat., vol. i. p. 110.
(5) Deschamps has mentioned an instance of this in Sedillot, Recueil périodique, vol. xxvi. p. 275-279.
(6) We have mentioned several cases in our Handb. der path. Anatomie, vol. i. p. 470-472.
(7) Consult also, on the wasting of the heart, Laennec (De l’ausc. Med. vol. ii. p.
291), and Bertin (Des mal. du cœur, p. 387). The latter admits two kinds ; one where the walls of the heart are collapsed, the other where the same parietes, especially those of the ventricles, are, on the contrary, dilated, and at the same time become thinner ; this is the state termed passive aneurism. F. T.
(8) Different instances of the simple increase of the mass of the heart have been reported by Vetter, Aphorismen aus der pathologischen Anatomie, p. 99. — Legallois, in the Bullet, de l'Ec. de Med., 1813, 1814, p. 69. — Morgagni, Ep. anat. med., 30 to 20. — Burns.
(9) We find several cases of it in Morgagni, Epist. anat. 18 to 28, and 30. — Corvisart, Malad, du cœur. p. 61.
(10) Many instances of this anomaly are mentioned in Burns. — Morgagni, Epist. anat., 18 to 2, and 14. — Dundas, On a peculiar disease of the heart, in the Med. sure . Trans., v©l. i. p. 37.
214
DESCRIPTIVE ANATOMY.
luted and sometimes united.(l) The last two are termed aneurisms of
the heart, which in the first case is called active, and passive in the
second. The active aneurism is more common on the left side and
the passive on the right. These two states usually coexist, the left
side being dilated actively, and the right side passively, to a greater
or less degree. (2) Sometimes the parietes of the left side have only
become thicker, and those of the right side are on the contrary
thinner, with or without dilatation at the same time. (3) However
it often happens that one part or the other is diseased, each in its
(1) This distinction neglected by Corvisart who understands by the terms active aneurism and passive aneurism only a dilation of the heart with a thickening or thinness of its parietes, was made by Bertin in 1811, in a memoir presented to the Institute. Bertin admits three distinct forms of hypertrophy of the heart, that is, of its total or partial fleshy thickening : 1st, simple hypertrophy, in which the cavities of the organ preserve their natural capacity, at the same time that the parietes are more or less thickened : 2d. aneurismal hypertrophy , in which the cavities are dilated and the parietes are thickened ; this is the active aneurism of Corvisart : 3d, concentric hypertrophy, in which the thickening of the parietes is attended with a greater or less contraction of the cavities. He also distinguishes two binds of aneurismal hypertrophy ; one in which the parietes are thickened, and the other where the parietes preserve their natural thickness, so that the increase takes place in some measure according to the extent and the circumference, or according to the surface. He has also remarked, that in the hypertrophy of the ventricles the thickness often diminishes from the base to the point, but it is sometimes about the same at the point as at the base, and in some cases is more marked in its centre, and diminishes toward the point and even toward the base. It may be equal to fifteen lines, and more, although Laennec asserts that it never exceeds four or five lines. Sometimes we find in the same ventricles one portion which is dilated and thickened, and another contracted and thickened, or one part thin, while tbe other is thick. We sometimes observe a great difference between the parietes of the ventricles, especially on the right side, and the fleshy pillars, the latter being doubled or tripled in extent, while the parietes are not, or but very slightly, thickened. In other cases, the hypertrophy of the left ventricle seems to take place at the expense of the pillars, which are effaced or are hardly visible. The hypertrophy of the left ventricle is generally attended with that of the septum. We sometimes observe also a hypertrophy of the interventricular septum only. The fleshy pillars of the right ventricle have been found so thickened and intercrossed that there was hardly any cavity. Hypertrophy also often affects both ventricles at once, but not unfrequently they present an opposite state. The point of the thickened ventricle always descends lower than that of the other. The three forms of hypertrophy are observed in the auricles, but the aneurismal is the most common. The thickening is nearly equal in all the extent of the pariete3, especially in the left auricle. The muscular fasciculi of the right auricle sometimes increase in volume. Finally, in certain cases, the parietes of this auricle are so much thickened in all their parts, that they imitate those of the corresponding ventricle. Again, whatever may be the form of the hypertrophy, Bertin admits, as its immediate and proximate cause, an irritation applied to the heart, which increases the activity of the phenomena of nutrition in this organ (Des maladies du cœur, p. 282). He admits also three kinds of dilatation of the heart, or to proper aneurism : 1st, dilatation, with thickening of the parietes, or aneurismal hypertrophy ; 2d, dilatation, with thinness of the parietes ; the passive aneurism of Corvisart, which is more rare than the preceding ; 3d, dilatation of the cavities, they being of their usual thickness, or simple dilatation, which has not hitherto been regarded. To these three classes he adds a fourth, which is doubtful ; the mixed dilatation, in which the parietes of the dilated cavity are thicker in some parts and thinner in others, and of their natural thickness in the rest. (Ibid, p. 368.) Consult also, on hypertrophy of the heart, Lallemand, Observations pour servir à l’histoire des hyper sarcoses du cœur, in the Archiv, gen. de méd. vol. v. p. 520. F. T 23.— Testa. Mal. del cuore, iii. c. xv.
AXGEIOLOGI .
215
usual manner.(l) The disease does not necessarily effect an entire
half. Generally, passive aneurism exists only in the right auricle,
and active aneurism only hr the left ventricle, whether these two
states exist alone, or whether they are both found in the same heart.
Sometimes however, but rarely, the right side is entirely or partially
thicker than usual, or at the same time dilated ; and then sometimes
the left side is also affected and sometimes it is not : sometimes also
it presents a passive aneurism, or at least its walls have become
thinner. Perhaps the passive aneurism is still more rarely confined
to the left ventricle, while all the other parts of the heart are in the
normal state. (2)
These affections are confined to one part of the heart only, much more generally than they are extended to the whole of it. Nevertheless, if we except the active aneurism of the left side, combined with the passive aneurism of the right side, which is frequently observed, we sometimes find hearts which are affected equally in every part. (3)
The diseased cavity of the heart is most generally dilated in its whole extent. A partial dilatation in the form of a cul-de-sac rarely exists.
The substance of the heart is sometimes, but very rarely, thicker in some parts from round excrescences which project on its internal face. We know of but one instance of this arrangement, and the specimen is in our cabinet. This is still more curious, as it throws much light on the formation of the polypi of the heart, which are explained with difficulty unless we admit that one or more of these excrescences are detached from then place of origin.(4)
§ 1323. The anomalies in the form of the heart relate either to its external or to its internal arrangement, or finally to both.
They are congenital much offener than accidental.
§ 1324. The congenital anomalies in the external form are,
(1) We find instances of the active aneurism of the left ventricle in Lancisi, De rep. mort., p. 137. — Lafaye, in the Mém. de Paris, hist., p. 29.— Corvisart, Journ. de méd. vol. xi. p. 257.— We find cases of the passive aneurism of the right ventricle only in Fleury, Bull, de l'Ec. de méd., 1807, p. 124. — Morgagni, Epist. anat., m. 18 to 6.
(2) We find one case in Corvisart, p. 99.
(3) Different cases which prove this proposition, both in respect to the simple thickening of the parietes, and also to passive aneurism, are mentioned in Vetter, loc. cit., p. 99. — Burns. — Morgagni, Ep. anat., m. 18 to 2, 23, 30, ep. 53 to 9. — Corvisart, p. 61, 87. — Testa, loc. cit., vol. iii. ch. xvi. a. 7, 8, p. 361-367.
(4) Laennec relates several cases of this abnormal arrangement ( De l auscultation mediate, vol. ii. p. 344) which he terms globular excrescences of the heart, and which he compares to the excrescences of the valves. Meckel’s mode of explaining them cannot be maintained. Bertin (loc. cit., p. 444) not only admits with Corvisart, Testa, Burns, Creysig, and Laennec, that polypi, or rather fibrinous concretions, may form, during life, in the heart, as in all other portions of the sanguineous system'; but he also adopts Kreysig’s theory, and regards them as resultingfrom an effusion, which occurs after inflammation of the inner membrane of the heart. These concretions are most generally free from all adhesions, at least organic ; but sometimes also they are perfectly organized, and have numerous vessels injected in bright red or black. This important fact, of which Bouillaud has published two remarkable instances ( Obs. et cons. nouv. sur Voblitér des veines, in the Arch. gén. de méd., voi. v.
216
DESCRIPTIVE ANATOMY.
1st. The form of the heart is more rounded ; this is sometimes met
with alone, but is usually attended with several other anomalies already
mentioned, or which remain to be described, as prolapsus, perpendicularposition, &c.
2d. The deep fissure of the summit of the heart, to which our remarks on the preceding anomaly apply.
The accidental anomalies in the external formation are principally the solutions of continuity , which must not be confounded with those which are congenital, for the latter implicate the inner form, and they consist essentially in anomalies of the connection of the two portions of the heart.
Solutions in continuity of the heart are fissures or wounds.
Fissur es(l) occur most generally after those pathological changes which supervene in the substance of the heart itself, or in the arterial trunks. They less commonly depend on external injuries, which do not directly affect the substance of the heart, but act either on the parietes of the thoracic cavity, or on the organs within it.
1st. The changes in the substance of the heart giving rise fissures, are produced principally by inflammation , ulceration , and gangrene, {2) which soften this substance, (3) and gradually destroy it in one or more parts, so that there is finally a solution of continuity during the systole or the diastole. One can imagine that this species of fissures is equally frequent in all parts of the heart.
2d. Those on the contrary which depend on morbid changes supervening in the arterial trunks occur in some points more frequently than in others, and are probably more common in one sex than in the other.
p. 95, and 101), throws great light on the theory of the formation of polypi of the heart, inasmuch as we can no longer doubt that their organization takes place in the same manner as that of the false membranes, and depends en the same cause.
F. T.
(1) Bland, Mémoire sur le déchirement sénile, du cœur, in the Bibliothèque médicale , vol. lxviii. p. 364.— Rostan, Mémoires sur les ruptures du cœur, in the Nouveau, journal de mêdicine, vol. viii. p. 265. — A. J. L. Bayle, Observation de rupture du. cœur, in the Revue médicale, vol. iii. p. 96.— Carrier, Observation sur une double rupture des parois du ventricule gauche du cœur, in the Journ. univ. des sc. médicales, vol. xxxv. p. 358.
(2) Although, strictly speaking, gangrene of the heart is not impossible, it is at
least so rare that those observers in whom the fullest confidence can be placed have not seen it. Thus Corvisart does not hesitate to say that no well authenticated case of it exists. Most of the facts which have been reported, being stated in a faithless manner, should be reeeived only after strict examination and admitted with distrust. Such is the very wise opinion of Bertin ( Des malad, du cœur, p. 408), who thinks that these facts should be considered as acute softenings of the heart rather than real gangrenous affections. F. T.
(3) Laennec first called the attention of pathologists to softening of the heart, of
which he admits two species, one where the substance of the organ is more deeply colored, and the other where it is discolored, or rather has a whitish or yellowish tinge ( De l’auscultation, vol. ii. p. 186). He asserts that he has found this softening in all cases of fevers called essential, when he has attended to them. He does not however consider this as a character of inflammation. Bertin thinks it is caused by inflammation of the heart, which is acute when it is of a deep red or even brownish, and chronic, when the muscular tissue of the organ is discolored and becomes pale or yellowish. F. T.
ANGEIOLOGY,
21Ÿ
Thus the part of the heart most frequently ruptured is the left ventricle, and this accident is more common in the male than in the female, because the ossification of the valves and the contraction of the arterial orifice, which is a consequence of it. are observed in the left more frequently than in the right, and in the male oftener than in the female. When this occurs, the substance of the heart is thinner less frequently than it is thickened and hardened.
The normal difference between the right and left portions of the heart also accounts for the greater frequency of the fissures on the left side, since the right side is less tense and more extensive than the other.
The normal arrangement of the heart explains also why fissures occur in one part of the ventricles rather than in another.
This point is commonly the place where the arterial trunk unites to the ventricle,(l) because there is no continuity in this place between the fibres of the heart and those of the arteries.
The place where fissures occur most frequently, next to this, is the apex of the heart, as there the substance of the organ is thinnest.
Contusions of the chest or the forcible penetration of foreign bodies, as of musket-balls, also tear the heart, even when the parts surrounding this viscus are uninjured.
Besides these fissures, which are visible externally and which pass through the heart entirely, there are others which are much less frequent, and where either the tendons of the venous valves or the fleshy pillars are detached from their points of insertion. The latter almost always result from violent efforts or emotions.(2)
Wounds of the heart are or are not attended with the presence of • the wounding body. In both cases they pass through all the substance of the organ or affect only its surface. Wounds attended with the presence of the foreign body are seen principally after musket-wounds, when the ball, not having power enough to pass through the- heart, remains within it or probably insinuates itself by degrees, the wound cicatrizing behind it as it advances. In both these cases the individual has sometimes survived so severe an injury, but this is rare. (3)
(1) This assertion is not correct. Ruptures of the heart occur always, or most
generally, toward the apex and the anterior part, that is, in the thinnest part. In tins respect, Rostan has observed that the disproportion of the diameter is such, that often, when the diameter of the upper part of the ventricle is sixteen or eighteen lines, which he asserts is the greatest development which it can attain, the apex is only two lines thick. Bayle has mentioned, that of nineteen instances of rupture of the heart, fourteen existed in the left ventricle, principally its anterior face near the apex, three in the right ventricle, one in the apex, and the other in the interventricular septum. In most of the cadavers the heart was remarkably soft, and in some cases a brownish color was observed around the perforation. These two circumstances support Bertin’s opinion, who (Des maladies du cœur) thinks that the preceding erosive inflammation plays an important part in these perforations, as in those of the stomach and intestines. P. T,
(2) Corvisart, loc. cit., p. 256, De la rupture partielle du cœur.
(3) We find an instance of the first case in the Diet, des sc. méd. vol. iv. p. 217, and one of the second in Penada, Saggi sc. di Padova, vol. iii. part 2, p. 59.
Vol II 28
218
DESCRIPTIVE ANATOMY.
Penetrating, cutting, or pricking wounds are always and almost immediately mortal.(l) In order to conceive of a contrary case, we must
admit that the wounding instrument penetrates gradually. (2)
§ 1325. Most of the deviations in form in the inner parts of the heart are congenital. They comprise, 1st, those which cause no derangement except in the circulation of the blood ; 2d, those which derange the formation of the blood.
§ 1326. The deviations of form in the first class consist principally in the abnormal arrangement of the several orifices of the heart.
Among these are :
1st. The abnormal narrowness of the venous orifices of the ventricles .(3) This anomaly occurs most frequently on the left side, and is not rare. The mitral valve is then always thickened, more or less hardened, and often ossified. It is very doubtful if this anomaly ever be congenital. At least it is not so generally.
2d. The abnormal narrowness of the arterial orifices of the ventricles This congenital aberration occurs most frequently on the right side, and almost always results from a contraction, often also from an adhesion of the valves.
(1) Wounds of the heart are generally mortal after a few moments, or at most some hours. Some wounded persons have been known to survive one or five, seven, thirteen, seventeen, and twenty days, after penetrating wounds. See the surgical part of tire article Cœur, by Begin, in the Diction, abrégé des sc. medic., vol. iv. p. 493.
F. T.
(2) Although it did not form apart of our author’s plan to speak of the alterations
in the texture of the heart, we think it necessary to say a word upon its hardening, the theory of which appears to be intimately connected with that of its hypertrophy, its polypi, and its softening, that is with its irritation more or less approaching to the degree usually considered as inflammation. General hardening of the heart has not yet been noticed ; but it may be more or less extensive and sometimes invade an entire half of the heart. It is often confined to the internal or external face, where it is presented under the form of incrustations. The fleshy columns and the septum may also be the exclusive seat of it. It presents several degrees. Simple hypertrophy is the first and ossification the last. There are different shades between these two extremes ; sometimes the substance of the heart, of a bright red color and almost healthy in appearance, resembles in hardness a fibro-cartilage, and resists or grates when cut : sometimes it presents a cartilaginous density and solidity : again it is still harder and sounds like horn, as Corvisart says ; sometimes it resembles earth or sand (Bertin, Des mal. du cœur, p. 401). Ossifications of the heart are not rare in man. Meckel has collected several instances in his Dissertatio de cordis conditionilus abnormibus, Halle, 1802, and in his Manual of Pathological Anatomy. It is curious that in many animals, especially in the ruminantia, there is very often a bone in the heart. This has long been known in regard to the ox and the stag. See on this subject Keuchen, Diss. de ossiculis c cor dibus animalium, Groningen, 1772. — Jaeger, lieber des Vorkommen eines Knochen im Herze des Hirsches; in th e Deutsches Archiv für die Physiologie, vol. v. p. 113. — F. S. Leuckart, Bemerkungen über den Herzknochen des Hirsches ; same journal, vol. vi. p. 136. — We think it worthy of mention, however, that Masuyer has found 1,7 of phosphoric acid, 2 of uric acid, 3 of animal matter, 5,3 of lime, in twelve grains of the ivory substance coming from the ossification of the valves of the heart, from its external face at the base of the right ventricle, and from the aorta, and also from the large branches which arise from it (Journal de la société des sciences, agriculture, et arts , de Strasbourg, 1824, No. 3). The presence of uric acid in this case is remarkable as an analogy with what is seen in arthritic concretions. F. T.
(3) Abernethy, On a diminution in consequence of disease of the area of the aperture, by which the left auricle of the heart communicates with the ventricle of the same f in the Med. chir. trans. vol. i. p. 27.
A.NGEIOLOGY,
219
od. The deficiency or adhesion of the valves, especially those of the
arteries, sometimes occurs, and is not generally congenital but accidental. The absence of the valves is caused by their destruction by
suppuration, and their adhesion results from inflammation and ossification.
4th. Jin excess or deficiency in the number of the valves , which is seen particularly, but yet seldom, in the pulmonary artery, and much less frequently in the aorta. We find four valves more commonly than two.
§ 1 327. The essence of the deviations in form of the second division is an abnormal communication between the systems of red and black blood. They have no influence on the formation of blood, or when they possess it, the arrangement is such that the black blood becomes less venous or the red blood less arterial. In both cases the abnormal union of both the systems of blood may take place in very different parts.
1st. The abnormal communication of the first kind depends,
a. On the insertion of one, of several, or of all the pulmonary veins in the vena cava superior. We have a case of this kind before us.
b. On the existence of an accessory pulmonary artery, which arises from the ascending aorta.(l)
2d. The abnormal communications of the second kind occur either between the auricles, or the ventricles, or in the large vascular trunks. Many or all these anomalies are not unfrequently combined in the same subject.(2)
a. The most simple form is a single heart, consisting of one muscular cavity.
b. Next follows the formation where only one auricle and one ventricle exist, whence a single vessel, the aorta, arises, from which the pulmonary artery branches off, while the pulmonary veins open into the auricle, or even, by a formation still more abnormal, into the vena cava superior.
The formation is more perfect when the heart is divided by a septum into two halves, and the aorta and the pulmonary artery arise by separate trunks, but the septum is imperfect.
c. In this case the septum of the ventricles and of the auricles is perforated and the foramen ovale is open, which is the case most frequently; or,
& Only the septum between the ventricles is perforated, a more un, frequent formation ; or,
e. Only the foramen ovale is open ; this is the most usual.
(1) We have collected all the known cases of this anomaly, in the De monstrodà duplicitate, p. 55, and in Handb. der pathol. Anat., vol. ii. p. 134.
(2) The different degrees and in general most of the species of this class of anomalies are described in our Handbuck der pathol. Anat., vol. i. p. 422-470, vol. ii. p. 133, 134. — Farre, Pathological researches, Essay 1, On malformations of the human hears, London, 1814.— J. C. Hein, De cordis deformationibus quce san g-uinem. renosum cum. arterioso ipisceri permittunt , Gottjngen, 1816.
220
DESCRIPTIVE ANATOMY.
The septum of the ventricles is perforated generally in one deter tm
nate place, viz. the base ; so that sometimes the aorta, sometimes but
more unfrequently the pulmonary artery, arises from both ventricles :
in the latter case the aorta arises as usual, but forms only an ascending
portion, and terminates in the left subclavian artery, and the descending
aorta comes entirely from the pulmonary artery.
The interauricular septum is frequently developed imperfectly, that is, its formation has not followed the course mentioned above (§ 1305), but the pressure of the left auricle can then complete it ; so that the passage of the blood from this auricle into the right becomes impossible. Sometimes however, but more unfrequently, from the absolute or relative smallness or deficiency of the valve of the foramen ovale, this opening is so large, that the right and left auricles communicate freely. This. continuance of the foramen ovale is more unfrequent than the perforation of the septum, although its imperfect closure, produced in the manner stated above (§ 1305), is an anomaly still more frequent than this.
The abnormal arrangements of the large vascular trunks, which render the hematosis imperfect, are,
f. The obliteration or the considerable contraction or deficiency of the pulmonary artery, states which commonly but not always attend one of the anomalies mentioned above.
g. The continuance of the arterial canal, which seldom occurs alone, but is generally attended with one of the anomalies already described Or which remain to be mentioned.
h. The existence of a second pulmonary artery, which arises from the right ventricle and terminates in the aorta. Finally,
The transposition of the origins of the arterial or venous trunks, viz.
i. The origin of the pulmonary artery from the left and of the aorta from the right ventricle, while the venous trunks empty themselves in their proper places.(l)
k. The insertion of the veins of the body into the left portion of the heart, or into the pulmonary veins, or frequently into the pulmonary artery. This occurs in different ways. We have before us a preparation where the large coronary vein of the heart, instead of terminating in the right portion, opens into the left auricle of the heart. In another case, the vena azygos is divided near the heart into two branches, one of which goes to the right, the other to the left auricle. Sometimes the pulmonary arteries evidently anastomose with the azygos vein.
The physiological influence and importance of these anomalies are not the same.
In the first point of view, we may state it as a principle, that the first six arise because the formation of the heart is arrested at an early period of development, and because it is a repetition of the formation of the
(1) Tiedmann has described and figured a case of this anomaly in the Zeitschrift Physiologie,' ch. i. p. Ill, pi. 7, fig. 9.
ANGEIOLOGY.
22 L
heart in some of the lower classes of animals, particularly the crustaceous animals, the mollusca, and the reptiles. The others are normal
in no period of life, but belong to the class of anomalies which affect the
quality of the organs.
Hence also why the former are more frequent. The influence on the hematosis is much more injurious, the greater the mixture of the black and red blood : it is very slight either when the abnormal communication is merely by the small vessels ( k ), or when the communication is interrupted by the arrangement of the parts at the moment when it might be injurious : this occurs in most cases where the foramen ovale becomes open. The derangement is very great in other cases.
The effects which result from them are, frequent recurrence of asthma, extreme weakness of the voluntary muscles, great debility in the nervous system, often a defect in nutrition and development, and a blue color of the body. Death usually supervenes in the early periods of life, although in a few rare cases the patient has lived till the age of fourteen. At certain periods, especially during dentition and at the age of puberty, the symptoms recur more frequently and with greater violence. The cause of these symptoms and the essence of the derangement is, the mixture of venous with arterial blood and the distribution of this mixed blood in the body ; they arise sometimes, as for instance when the pulmonary artery is entirely closed or does not exist, or when the pulmonary artery arises from the left ventricle and the aorta from the right ventricle, because the organs of the body receive pure venous blood.
From the blue color of the skin, which depends upon the venous blood not being changed into arterial blood, (1) this disease has been termed cyanopathia ( morbus r.Å“ruleus , cyanopathia , cyanosis). ( 2)
(1) Bertin has very properly remarked that this explanation cannot be -admitted,
for three reasons : 1st, because cyanosis did not exist in cases where the right and left heart communicated ; 2d, because it did exist in other cases where this communication did exist ; 3d, because that if the blue color of the skin was produced by this deviation of formation, it ought to exist also in other parts, which is not the case. Besides, as Fouquier justly remarks, the skin of the fetus, in which only black blood circulates, is not blueish. Bertin thinks then that the blueish color of certain parts, in different individuals where the two hearts communicated, depends on the stagnation of the blood in the right cavity and in the venous system, which is in a manner gorged with it ; this explanation seems more rational, inasmuch as this anomal v in the formation of the heart is often attended with a contraction of the orifices or of the pulmonary arteries. F. T.
(2) Kwiatkowski, Diss. actiologiammorbi cærulci amplifie ans, Wilna, 1816. — Hein, Diss. de istis cordis deformationibus quœ sanguinem venosum cum arterioso misccri. permittunt , Gottingen, 1816. — J. F. Meckel, Essai sur les vices de conformation du cœur qui s' apposent à la formation du sang rouge ; in th e Journ. complêm. des sc. med., vol. iii. p. 224-301. — Gintrac, Observations et recherches sur la cyanose, ou maladie blue, Paris, 1824. — Louis, Observationes suivies de quelques considerations sur la communication des cavités droites avec les cavités gauches du cœur ; in the Archives generales de médecine, vol. iii. p. 325, 485.
