The valvular structure of the heart, anatomically and physiologically considered : with a view to exemplify or set forth, by instance or example, the wisdom, power and goodness of God, as revealed and declared in Holy Writ : the Warneford prize essay, for the year 1841 / by William French Clay.

  • Clay, William French, -1889
Date:
1842
Catalogue details

Licence: Public Domain Mark

Credit: The valvular structure of the heart, anatomically and physiologically considered : with a view to exemplify or set forth, by instance or example, the wisdom, power and goodness of God, as revealed and declared in Holy Writ : the Warneford prize essay, for the year 1841 / by William French Clay. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    cayarum ; the other part is lodged between the right ventricle and origin of the aorta, appearing as a loose appendage to the general cavity, and, from some resemblance it bears to the ear of a dog, the term auricula is used to designate it. The right auricle in the greater part of its extent is free, but, internally, it becomes iden- tified v^ith the left. The lov^^er part thereof (i. e.J of the right auricle is identified with its corresponding ventricle; behind are the orifices of the two vente cavse. The inner aspect of this cavity presents four surfaces;—a posterior, where the main venous trunks open; an anterior, formed by the auricular appendage, containing numerous muscular bands (musculi pectinati); an external, on which also are a number of muscular bands, similar to those men- tioned; an internal, which is nearly smooth, forms the septum, or partition, between the two auricles. The superior vena cava opens at the upper and posterior angle, looking downwards and forwards; the inferior vena cava at the posterior and inferior angle, and is directed upwards and backwards. These openings are circular, that of the inferior being the larger. Around the left edge of the supe- rior, as it enters, there is a band of muscular fibres; another, though less perceptible, is placed around the right posterior margin at the angle of junction with the right edge of the inferior vena cava. This forms what is now called, tuberculum Loweri. On the inner surface, just above the orifice of the inferior vena cava, is seen an oval depression, indicating the situation of an opening, which had existed during foetal life, called fossa ovalis : it is limited by a prominent ring, annulus fossas ovalis. The upper anterior margin of this depression being thickened, induced Vieussens to believe that it prevented the blood falling from the superior vena cava into the inferior, which Lower considered might be effected by the tubercle, or projection, which he discovered at the junction of the veins ; the position, however, of their orifices, will alone obviate such an occur- rence. The upper border of this depression is often found imper- fectly united to the septum, which slightly overlaps it; thus ob- taining a kind of valvular arrangement sufl&cient to prevent any communication being effected during the contraction of the auricles. Immediately above the margin of the inferior cava is a crescent-like fold of the lining membrane (valvula nobilis Eustachii), placed vertically, and extending up towards the annulus fossae ovalis. This valve assumes various appearances in the adult; it is of considerable size in the foetus, becoming gradually obliterated as age advances, and is, in old persons, almost indistinct. Its posterior surface looks towards the openings of the inferior vena cava, while the anterior corresponds to the cavity of the auricle; its free edge is somewhat concave, and occasionally reticulated. Below this, and between it and the opening into the ventricle, is situate the common orifice of the coronary veins, protected by a peculiar valve, of a semilunar shape, the free and concave margin of which is directed upwards; it is sufficiently broad entirely to close the opening, is occasionally reticulated, and, instead of one valve, there may be two or three, placed behind each other. Both these valves are produced by the lining membrane of the heart being doubled back upon itself; the Eustachian valve also frc-
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