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FATTY DEGENERATION OP ARTERIES. 339

namely, we have to deal with very soft parts, in which much fluid or juice has been present all along, the granules fall asunder. The medium which bound them together and enabled them to retain the globular form, namely, a remnant of the old cell-contents, is gradually dissolved. The globule breaks up into a crumbling mass, which is often still somewhat coherent in places, but from which one drop of fat after another is detached, so that the correspondence with milk is very beautifully displayed.

This is the manner in which the disintegration of nearly all parts takes place, which essentially consist of cells and naturally contain a good deal of fluid, as for example pus among familiar pathological products (p. 182, Fig. 66). If, on the contrary, the parts are in themselves somewhat more rigid, so that movement in, and displacement of, the fatty mass takes place with less facility, the fat remains in the form of the previous cell. Of this we meet with an example in the fatty degeneration of the walls of arteries.

In the aorta, the carotids and the cerebral arteries, changes of the inner coat are often seen with the naked eye of such a nature, that small, whitish spots of a rounded or angular form, occasionally running one into the other, project somewhat above the surface. If an incision is made at these spots, it is found that they are quite superficial, that they lie in the innermost layer of the internal coat and must not be confounded with the really atheromatous condition. If such a spot be cut out, it is found that a fatty degeneration of the connective-tissue-corpuscles of the innermost coat has taken place; and since they are branched cells, we do not here have granule-cells in their ordinary rounded form, but often very long, fine bodies, which here and there swell up into the form of a spindle or star, and in which the fat-granules lie heaped up like strings of pearls, whilst between there still remains intermediate substance quite intact. It is the cellular elements of the connective tissue which in these cases undergo the change in their totality. Afterwards the intermediate substance also softens,

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the cellular fat-granule masses fall asunder, and the current of blood carries away the particles of fat with it. In this way a number of uneven places are produced upon the surface of the vessel, which swell up as long as the process continues, afterwards become worn away (usurirt), and acquire a slightly velvety appearance, without there being any ulceration in the proper sense of the word. This is a particular form of fatty usure which occurs in many parts, as for example in articular cartilages, and even on the surface of mucous membranes, for example, that of the stomach (Fox). But at no time does the matter accumulate in such abundance as is the case in abscesses which have undergone fatty degeneration. If, on the other hand, a similar process commences beneath the surface, as in the atheromatous process, the fatty degeneration then proceeds from below upwards, and the surface is not reached until the last. By softening, the so-called atheromatous deposit (Heerd1) is

Fig. 113. Fatty degeneration of cerebral arteries. A. Fatty metamorphosis of the muscular cells of the circular-fibre coat. B. Formation of fat-granule cells in the connective-tissue-corpuscles of the internal coat. 300 diameters.

1 Heerd (hearth) in the sense in which it is here employed, has no precise equivalent in English, although it exactly corresponds to the French foyer. "It denotes," says the Author, "the spot, where the fire of the disease burns, but expresses at the same time that this spot is a limited one." I have therefore translated it by various words, such as, deposit, depot, seat (of the disease), collection, patch (atheromatous), focus, &c, Tkansi.

FATTY METAMORPHOSIS. 341

produced, which contains a softened mass resembling the contents of atheromata [sebaceous,1 or epidermic, cysts) of the skin, in which the mixture of sebaceous matter and epidermis produces a pultaceous mass. What we find in the arteries is a mixture of fatty debris with softened intermediate substance; and, since the fatty mass is shut off, a kind of enclosed deposit results—as it were an abscess. It is only after the softening has proceeded to some extent that the surface gives way, and matters issue from the cavity into the vessel, whilst others proceed from the blood into the cavity.

In this manner destruction, demolition, ulceration is produced, and ultimately the atheromatous ulcer, a species of ulcer very nearly allied to the ordinary forms of ulceration, but indebted for its origin to fatty metamorphosis alone. It is a product of the [atheromatous] deposit, but it no longer contains any formed elementary parts. Cholestearine indeed may still be set free, but we have really and truly to deal with a destructive and ultimately ulcerative process. It is only in those parts, in which, as in the mammary and sebaceous glands, there is a succession of new cells, that the process of fatty metamorphosis can continue for any length of time without leading to such an annihilating result. But, even in these instances, the different cells affected ultimately perish and break up, as in the really fatty degeneration.

1 These cysts are wrongly called sebaceous, inasmuch as they are essentially epidemic, and are generally derived, not from the sebaceous glands, but from the hair-follicles. The atheromatous matter is in these cases chiefly composed of degenerated and disintegrated epithelium. — From a MS. note by the Author.

LECTURE XVI.

APRIL 14, 1858.

A MORE PRECISE ACCOUNT OF FATTY METAMORPHOSIS.

Fatty degeneration of muscles.—Fatty metamorphosis of the substance of the

heart.—Formation of fat in the muscles in distortions. Corpus luteum of the ovary.—Fatty metamorphosis of pulmonary epithelium.

—Yellow softening of the brain.—Arcus senilis. Optical properties of fattily degenerated tissues.—Renal epithelium in Bright's

disease.—Successive stages (cloudy swelling, fatty metamorphosis, fatty

detritus (debris), atrophy).—Inflammatory globules.—Similarity of the

result in inflammatory and non-inflammatory changes. Atheromatous process in arteries —Its relation to ossification.-—Inflammatory

character of the process; its analogy with endocarditis. — Formation of

the atheromatous deposit.—Appearance of cholestearine.—Arterio-sclerosis.

—Endoarterilis.—Calcification and ossification of arteries. Mixed, activo-passive processes.

To-day, gentlemen, I have sent round a few specimens of fatty degenerations, in part to serve as a supplement to what you saw at the last lecture.

One or two of these preparations are intended to display the fatty degeneration of the substance of the heart. You will observe that, even with the naked eye, certain changes can be recognized in the heart, namely a discoloration of its whole substance (which no longer presents the red hue of muscle, but wears a pale yellow tint), and besides peculiar spots on the papillary muscles. If you examine these more closely, you will perceive, in the direction of the primitive fasciculi, short, yellowish streaks which communicate so as almost to present a plexiform arrangement, and pervade the substance of the papillary muscles, whilst they offer a striking contrast to the reddish colour of proper muscular substance. This is the perfect form of

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FATTY DEGENERATION OF MUSCLES. 343

genuine fatty metamorphosis of the real muscular substance of the heart, which differs most essentially from obesity » FlG-114of the heart, in which this organ becomes extremely fat and adipose tissue here and there so infiltrates its walls, that scarcely any muscle is to be perceived. Between the two conditions there always remains the notable difference, that in the former case whole portions of active substance are

interrupted by parts which are manifestly no longer capable of action.

I have besides brought you another specimen of muscle we obtained yesterday at the suggestion of our confrere Berend. A body, namely, with posterior (angular) and lateral curvature (Kypho-Skoliose) was brought for postmortem examination, and, when we examined the muscles at the point of curvature, we found the longissimus dorsi at the spot where it passed over the projection, converted into quite a flat, thin, pale yellowish mass. At one point the muscle has, with the exception of a membranous layer, entirely disappeared, its red hue has altogether vanished; towards the lower part the muscle also presents an abnormal appearance, but there it is composed of alternate longitudinal red and yellow streaks. This is the form exhibited by most fattily degenerated muscles which we find in distortions of the limbs, as for example, in the different kinds of club-foot. In these it generally turns out, that, in the parts corresponding to the yellow streaks, there is not only a real transformation of the muscular substance, but that an interstitial development of adipose tissue has also

Fig. 114. Fatty degeneration of the muscular substance of the heart in its different stages. 300 diameters.

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