PARCEL BLOOD — the dense coagulate which is formed in cardial cavities or a gleam of vessels in the conditions of dead stop of blood circulation. In prosection practice under S. to. mean a product of a posthumous blood coagulation in cardial cavities and vessels. The blood organized after hemorrhage in a perigastrium and fabric, as well as blood, the curtailed in vitro, more often call a clot. Pathologists a clot call also a product of coagulation of exudate rich with protein.
It is almost important to differentiate S. to. with blood clot (see) that quite often presents considerable difficulties. Page to. have an elastic consistence, a smooth surface more often and form as if exact molds of an inner surface of a vessel or cardial cavities, repeating difficult contours of mezhtra-bekulyarny spaces. Page to. it is not soldered to vascular walls and an endocardium, however owing to the branching the spayaniya can make a false impression, and it is not always easy to take it tweezers entirely without damage.
Macroscopically distinguish the gray, red and mixed (gray-red) S. to. Gray S. to. consists of randomly scattered platelet units and fibers of fibrin, among to-rykh not numerous uniform elements of blood (leukocytes, erythrocytes) meet. Red S. to. it is presented by the erythrocytes which are generally stuck together between sobon surrounded with network of fibrin. In the mixed S. to. layers are quite accurately distinguishable upper light gray and lower red. Each layer has structure according to gray and red S. to. The mechanism of their education is explained with the accelerated sedimentation of erythrocytes in the conditions of dead stop of blood circulation. On the other hand, at bystry blood coagulation of S. to. always has dark red color.
Biochemical bases of education of S. to. in essence do not differ from biochemical bases fibrinferment (see). Moreover, S. to. reflect intravital, at least for an agony, a condition of coagulant system of blood. There is open a question of, whether all to S. to., to-rye during the opening qualify as posthumous, were formed posthumously, but not in the period of an agony. There are bases to believe that in some cases inefficiency resuscitation (see) is explained by a bystry blood coagulation in the period of clinical death. Therefore as outward of S. to., and their quantity and localization can have diagnostic value at necropsy. E.g., at leukoses (see) preferential gray S. are formed to., at diseases, in the outcome to-rykh it is noted long agony (see) — the widespread mixed S. to., at the diseases which are followed by increase in coagulability of blood — massive red S. to., sometimes covering all cardiovascular system.
At asphyxia and sudden death from cardiovascular diseases cadaveric blood can not be exposed to coagulation at all and to remain liquid. According to A. V. Rusakov, it occurs owing to bystry disintegration of fibrinogen (fibrinogenoliz).
Subsequent changes of S. to. in vessels of a corpse can be various. If the mixed S. to. are exposed retractions (see) and to consolidation, friable red parcels can undergo a snap lysis owing to bystry emission of endogenous plasmin (see. Fibrinolysin ), under influence to-rogo there is a disintegration of fibrin — fibrinolysis (see). According to A. V. Rusakov, liquid state of cadaveric blood at sudden death (see) is a consequence of a fibrinolysis, i.e. bystry dissolution of red S. to., not in time to undergo retraction.
See also Postmortem changes .
Bibliography: A. I apricots. Private pathological anatomy, p.1, M. — L., 1947; Andreenko G. V. Fibrinolysis, M., 1979; The Inflammation, immunity and hypersensitivity, under the editorship of G. 3. Moveta, the lane with English, page 480, M., 1975; Davydovsky II. B. General pathology of the person, M., 1969; With t r at-to about in And. II. and Serov V. V. Pathological anatomy, M., 1979.
N. K. Permyakov.