Description of the dissection of a case of right aortic arch : with remarks on this and allied malformations / by Professor A. Thomson.

  • Thomson, Allen, 1809-1884.
Date:
[1863?]
Catalogue details

Licence: Public Domain Mark

Credit: Description of the dissection of a case of right aortic arch : with remarks on this and allied malformations / by Professor A. Thomson. 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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    and relations of the nerve on the right and left sides in man and the higher animals. It is extremely difficult, if not impossible, in a few words to give any precise statement, or to convey a clear idea of the nature of the genetic processes by which the form and position of the vessels above referred to are ultimately determined. I can do no more in this place than merely mention them as consisting mainly in the occurrence of various degrees of patency or occlusion of entire arches or of parts of them, and in proportional increase of growth or atrophy of those parts which may have remained open or been closed. But to these must be added another set of changes, consisting -in the lengthening or shortening of parts of the arches or stems of the vessels, which may have the effect not merely of altering the relative distances at which these vessels arise from the main stem, but even of collecting into one trunk, or of separating more widely from each other, any two or more of the vessels proceeding from one or more stems or arches. In conformity with the preceding statement of the general plan of development of these vessels, and in explanation of the accom- panying woodcut, which is designed to assist the comprehension of the reader by presenting a diagrammatic sketch of the aortic vascular transformation in man, the following^ table of the parts of the upper arterial system engaged in these transformations may be of use :— I.—PRIMITIVE FOETAL PARTS. 1. Primitive Arterial Stem or Aortic Bulb, afterwards divided by a septum into systemic or aortic and pulmonary canals. 2. Five Pairs of Arterial Vascular Arches (the branchial or visceral arches) proceeding from the primitive stem, or from its two primary branches, and forming by their union, 3. The Right and Left Dorsal Roots of the Aorta, which, having been at first separate, are at a very early period united in 4. The Descending Aorta. II.—SECONDARY PARTS. 5. Entire Persistent Arcii or Arches, proceeding from those which remain entirely patent and augment proportionally in growth. 6. Partially Persistent Arches, either a. Anteriorly, giving origin to the stems of the brachial and cephalic and of the pulmonary arteries, or b. Posteriorly, giving rise to a part of the internal carotid arteries. 7. Ductus Arteriosi, produced by temporary persistence of one or both the fifth arterial arches in connection with the permanent aortic root or roots. The various cases of abnormal form and position of the great arterial vessels connected with the heart, may be best arranged and understood by referring them to deviations from the normal