The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . SYSTEM the arterial cannula and the manometer was filled with a suitablefluid to preveiit coagulation of the blood: also to prevent morethan a trace of blood entering the connexions. A saturated solu-tion of sodium sulphate, or a I % solution of sodium citrate, mav beemployed for this purpose. Ludwig (1847) added a float providedwith a writing style to the mercurial manometer, and brought thestyle to write on a drum covered with smoked paper and drivenslowly round by clockwork—a kymograph By this
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . SYSTEM the arterial cannula and the manometer was filled with a suitablefluid to preveiit coagulation of the blood: also to prevent morethan a trace of blood entering the connexions. A saturated solu-tion of sodium sulphate, or a I % solution of sodium citrate, mav beemployed for this purpose. Ludwig (1847) added a float providedwith a writing style to the mercurial manometer, and brought thestyle to write on a drum covered with smoked paper and drivenslowly round by clockwork—a kymograph By this means tracings01 the arterial blood pressure are obtained, and the influence uponthe blood pressure of various agents recorded and studiecl. Forthe veins a manometer filled with salt solution is used, as mercurv-15 too heavy a fluid to record the far slighter changes of venouspressure. Ihe manometer may be connected with a recordingtambour. » The arterial blood-pressure record obtained with the mercurialmanometer exhibits cardiac and respiratory oscillations as shownin fig. iS. The method. ipleie om AUcbins Manwtl of Mfdidne. by permission of MacmBlaa & Co. Ltd Fig. 26.—Diagram showing General Relations of the Velocity ofthe Blood in the Arteries, Capillaries and Veins. ie flow in the large veins is approximately equal to that in therge arteries. In the jugular vein of a dog the mean velocity wasund to be 225 mm. and in the carotid 260 mm. per second. Thelocity in the capillaries has been measured by direct observationth the microscope. It is very small, 0-5-1 mm. per variation of velocity in different parts of the vascular systemexplained by the dilTcrence in width of bed through which the?earn flows. The vascular system may be compared to a streamuch on entenng a field is led into a multitude of irrigation channels; sum of the cross sections of all the channels being far greaterin that of the stream. The channels unite together again andve the field as on
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
