. Diseases of the heart and thoracic aorta. fibres, which are placed at their points of termination, the veins join the heart, the systemic venous circula-tion being still further protected from the backwash, whichnot unfrequently occurs through the tricuspid, even in con-ditions of health, by the valves of the veins themselves. Bythese means the onward flow of blood in one—a forward—direction is accurately maintained. The course of the circulation is diagrammaticallyrepresented in figure 3, while the passage of theblood through the heart takes place in the followingmanner:— At the c
. Diseases of the heart and thoracic aorta. fibres, which are placed at their points of termination, the veins join the heart, the systemic venous circula-tion being still further protected from the backwash, whichnot unfrequently occurs through the tricuspid, even in con-ditions of health, by the valves of the veins themselves. Bythese means the onward flow of blood in one—a forward—direction is accurately maintained. The course of the circulation is diagrammaticallyrepresented in figure 3, while the passage of theblood through the heart takes place in the followingmanner:— At the commencement oi the auricular diastole (andwhile the ventricular systole is taking place) blood beginsto flow from the great venous trunks into the auricular The chief cause, oi the motion of the blood, is the heart, but the onwardpassage of blood is also aided by the contraction of the blood vessels. Thiscontraction is partly the result of elasticity, and partly due to an active contractionof the muscular coat. Diseases of the FIG. 3. Course of the Circtilation. Description of YlG. 3.—Diagrammatic representation of the course of the circulation.{Modifiedfrom Dalton.) The arroivs indicate the course of the circulation. RV, the right, and LV, the left ventricles. RA, the right, and LA, the left auricles. Lungs, Liver (description in full). S, Stomach. Spl, Spleen. In, Intestines. K, Kidneys. Sc, Supra-renal capsules. P, Pelvic viscera. LE, Lower extremities. UE, Upper extremities and superficial parts of the head and neck. B, Brain. Sp, Spinal cord. PA, Pulmonary artery. PV, Pulmonary veins. AA, Branches of the ascending aorta. DA, Descending aorta. SV, Superior cava. IV, Inferior cava. 1 Caeliac axis, sending branches to the spleen, stomach, and liver. 2 Mesenteric arteries. 3 Renal arteries. 4 Arteries to the pelvic viscera. 5 Arteries to the lower extremities. 6 Arteries to brain and spinal cord. 7 Arteries to brain. 8 Arteries to spinal cord. 9 Arteries to the
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectheart, bookyear1884
