(Physiol. & Biol.) The contraction of the heart and arteries by which the blood is forced onward and the circulation kept up; also, the contraction of a rhythmically pulsating contractile vacuole; correlative to diastole.
... about the views of Galen. He thought that both the contractions and dilatations of the heart—what we call the 'systole' or contraction of the heart, and the 'diastole' or dilatation—Galen thought that these were both active movements; that the heart actively dilated, so that it had a sort of sucking power upon the fluids which had access to it. And again, with respect to the ... — Lectures and Essays • T.H. Huxley