Collection of facts illustrative of the morbid conditions of the pulmonary artery / by Norman Chevers, M.D.

  • Norman Chevers
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: Collection of facts illustrative of the morbid conditions of the pulmonary artery / by Norman Chevers, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    Omnes in eo conveniunt valvulse numero immimitas mote augeri, numero auctas mole minvii. It will be found, however, that the first, third, and fourth of the following examples, corroborate the statement of Meckel,and cor- respond with two cases observed by Petsche and Bizot*,inone of which the additional valve vras found singularly small, in the other quite rudimentary. The first in some mea- sure corresponds with an instance mentioned by Morgagni, in which one of the valves was larger than the rest. In the fifth instance the condition of the artery closely resembled that described by Dr. Thompson, the whole of the valves being regular and symmetrical in form. In the Museum at Guy's Hospital there are four preparations (numbered 1435^* 1413^^^) in which various modifications of this condition of the artery are remarkably well displayed. In one of these, three of the curtains are well formed, but the vessel is also furnished with an additional sygmoid pouch, which is capable of holding a pea. In a second there are four valves, but the septum between two of these is longer than that which separates either of the others, the free edges of the curtains having apparently been stretched downwards. In the third specimen there is a very minute imperfectly formed additional valve, formed by a little curtain supported above by slender isolated cords; these cords attach tiie upper margin of the valve, almost at its central part, to the arterial walls. The fourth preparation displays a still more minute extra valve, which is not only attached laterally to the artery by tendinous cords, but also presents a thin membranous bridle, which extends upwards from that por- tion of the free edge at which the corpus arantii is usually situated, and is united with the arterial wall above. This is the only specimen which I have seen in tlie human subject where a sygmoid curtain was attached to the artery by a tendinous cord occupying the situation of the corpus arantu, but such an an angement of parts is observed to be permanent in the upper row of valves defending the aorta of the shark ; and there is every reason to believe that, in the human heart, the primitive condition of a sygmoid valve is that of a membranous curtain attached to tlie vessel at its u]iper part by isolated tendinous cords. I have stated the crounds on which this conclusion is formed in a previous essayt, and I have no doubt that the corpora arantii are the vestiges of * Haller, Collect. Anntom. Dis. vol. vi. p. 77-1 ^lum. de la Soc\6i6 d'Observation, vol..., iiuoti'd by Dr. Tliouipson. .. , ' t Guy's Hospital llcporls, vol. vii. p. 414, and jilate 1. the attachments of the central chordae ten- dineie of the valves. The same collection also contains another specimen (marked 1413) which presents four perfectly symmetrical valves, which are in every respect healthy and natural in struc- ture, except that here, as in most of the other specimens, some of the lateral attach- ments of the curtains are formed by isolated cords ; a condition of parts which 1 believe to be in every instance congenital, and not the result of atrophy of the tissues of the valves. Origin of extra branches from the pulmo- nary artery. A few instances have been noticed in which one or other of the subclavian arteries took its origin from the pulmonary. Bres- cliet* mentions a case in which the left sub- clavian arose from this vessel; and J. F. Meckelf has described the origin of the right subclavian from the division of the pulmonary artery in a calf. Instances in ^ which the descending aorta, left subclavian, &c., apparently arose from the pulmonary artery, and in which the latter vessel com- municated with the innominata or left sub- clavian, belong more properly to another division of this subject. The lungs supplied by additional branches from the systemic circulation. In the course of the foregoing observa- tions, various instances have been alluded to in which obliteration or contraction of the pulmonary artery was in some measure compensated by the existence of branches passing to this vessel from the sub- clavians, or arch of the aort-., or by the estabhshment of a permanently dilated con- dition of the aortic bronchial arteries. In addition to tliese. Otto refers to several cases in which, besides the usual pulmonary artery, the lungs were supplied by accessory arterial bl anches ; for example, an instance where a large branch from the aorta, in the region of the sixth dorsal vertebra, passed to the lobes of the right lungj. Another case, where a single twig passed to the under lobe of the left lung§ ; and one in which very small pulmonary arteries passed equally to both lungs from the pericardial arteries||. A very remarkable instance of this kind has been related by M. A. Maugars, of Angers.^ The subject of this malformation was a child, act. 7 years, in whom a con- siderable artery, which arose from the * Quoted by Hasse. , , t Tabul. Anat. Path. Fas. u. p. 2, cited by °±°Hiiber, in Anat. Helvct. vol. viii. p. 85. § J. F. ivieckel, in his Arclnv. f. d. Physiol. vol. vi. p. 454. II .lacobson, m Meckel, vol. n. p. l.)4. II Sidellot, Uucncil IVrioil. vol. xni.; and lu Corvisart, Journ. de Mtd. An. x. 1 luv.