Blood

{bind) [AS., Mod]. The fluid that circulates through the heart, arteries, and veins, supplying nutritive material to all parts of the body. In the human being the blood of the arteries is bright-red and dichroic; that of the veins dark -red and monochroic. Blood consists of plasma and corpuscular elements, the latter being the red corpuscles, the white corpuscles, and the blood-plaques. In a cubic millimeter there are about 5,000,000 red and 10,000 white corpuscles. The red color of the blood is due to the hemoglobin contained in the red corpuscles. The total amount of blood is estimated at yV of the body-weight. “When exposed to the air it coagulates, forming a red clot and a vellowish fluid called serum. Healthy blood consists of 78 per cent, of water, and 22 per cent, solids. B. -Casts, tube-casts to which red blood-corpuscles are attached. B. -Corpuscles, Red, circular, biconcave discs floating in the blood. Red corpuscles are circular in mammals (except the camel), and elliptical in birds and reptiles. In man they are about 3- 2V0 ^ncn (7 f1) *n diameter and T o o mch thick. Colorle corpuscles are about one-third larger in diameter, 27V0 mcn (10 ft). They exhibit movements similar to those of the ameba. B.-crasis, the mixture of the constituents of the blood. When the blood-crasis is diseased or disordered, the condition is known as dyscrasia. B.- crystals, crystals of hematoid in. B., Defibrinated, blood from which the fibrin has been removed by agitating it with twigs. B.- disease, a synonym of Dyscrasia.. B. -fluke. See Bilharzia hematobia. B. -islands, a term applied to the groups of corpuscles developed during the first days of embryonic life, within the large branched cells of the mesoblast. B. -plaque. See B. -platelets. B.- plasma, the liquor sanguinis, or fluid part of the blood. B. -plate. See B. -platelets. B. -platelets, circular or oval, light-gray bodies found in the blood. They are from I to 1.3 //in size, and number from 18,000 to 300,000 in the cubic millimeter. Their function is not definitely known; they are an important factor in thrombosis. B. -poisoning, a morbid state due to the circulation of bacteria or their products, or both, in the blood, as the result of a local infection. B. -pre ure, the tension of the blood in the arteries. B.- root. See Sangninaria. B. -tumor. See Hematoma. 152