On the coagulation of the blood in the venous system during life : (a thesis for a medical act in the University of Cambridge) / by George Murray Humphry.

  • George Murray Humphry
Date:
1859
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Licence: Public Domain Mark

Credit: On the coagulation of the blood in the venous system during life : (a thesis for a medical act in the University of Cambridge) / by George Murray Humphry. Source: Wellcome Collection.

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    inasmuch as it rather militates against the view so much advocated by Virchow and some other pathologists, that por- tions of the clot are very liable to be detached, and to be car- ried along in the blood-current, till they cause obstruction and give rise to secondary coagula in distant vessels}. The extension of the clot in the direction of the heart is usually limited by the junction of some large vein which is sufficient to maintain the current in the main trunk. Often the clot does not reach quite so far as this, but ends on the peripheral side of the junction. Thus, when the clot com- mences at the junction of the iliacs, on one side, it commonly extends about half way up the common iliac; and, in a case of cancer of the uterus, in which the iliacs, on both sides, were obstructed, the clot extended up the vena cava nearly as high as the renal veins. Sometimes the clot reaches further, and terminates in a round or conical end on the cardiac side of the point of junction of some large trunk. In the peripheral direction it is prolonged to a variable extent into the tributary branches, but does not usually reach the small veins: indeed, the latter are very rarely obstructed, either primarily or second- arily, in this affection. The clot not only fills and chokes up the vessel, so as to prevent the passage of blood through it, but also distends or stretches it; and this distension, together with a certain amount of irritation resulting from the presence of a solid body in its interior, soon produces an effect upon the walls of the vein, the results of which are exhibited chiefly, or almost exclusively, on the exterior of the vessel. ‘Thus we soon find that there is inflammation of the investing cellular tissue, causing an effusion of serum, lymph, or pus; whereas, in the interior, there is commonly little change beyond a removal of the epithelium from the lining membrane, and more or less intimate adhesion of the clot to it. There may be also an 1 Mr Hewitt, Medico-Chirurgical Transactions, xxviii. 74, found the clot in one ease ‘‘enveloped in a perfectly distinct, transparent, smooth, polished | ‘membrane, presenting the appearances of serous tissue, with arborescent vessels in its structure.”
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