Читать книгу The Body at Work: A Treatise on the Principles of Physiology онлайн

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If the spleen be enclosed in an air-tight box (an oncometer), from which a tube leads to a pressure-gauge—a drum covered with thin membrane on which the end of a lever rests, or a bent column of mercury on which it floats—the pressure-gauge shows the changes in volume of the spleen. The long end of the lever, which records the variations of pressure in the gauge, may be made to scratch a line on a soot-blackened surface of travelling paper. A record of the variations in volume of the organ, which can be studied at leisure, is thus obtained. It shows that the spleen is sensitive to every change of pressure in the splenic artery. Small notches on the tracing correspond to the beats of the heart. Larger curves record the changes of blood-pressure due to respiration. A long slow rise and fall marks the rhythmic dilation and contraction of the spleen itself.

One of the three large arteries into which the cœliac axis divides delivers blood to the spleen direct from the aorta. The splenic vein joins the portal vein shortly before it enters the liver. Thus the spleen is placed on a big vascular loop which directs blood, not long after it has left the heart, from the aorta, through the spleen, to the liver.