. A text-book of comparative physiology [microform] : for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. of which nded). the ?eiy great ir work of roM play a vital ones the whole, it in every vital char- velooity of llaries, and Mition and the onflow of its oon- iosystemi, lecially the and the flt- d muacular Bry jiart, in rails of aU he heart it- i lowest in the atmos- oal consists ' and each of arterial rferenoe in )fly, but, to er as such respiratory imstances. nary divis- le hjs
. A text-book of comparative physiology [microform] : for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. of which nded). the ?eiy great ir work of roM play a vital ones the whole, it in every vital char- velooity of llaries, and Mition and the onflow of its oon- iosystemi, lecially the and the flt- d muacular Bry jiart, in rails of aU he heart it- i lowest in the atmos- oal consists ' and each of arterial rferenoe in )fly, but, to er as such respiratory imstances. nary divis- le hjsart is 'act in har- P the walls •ns are dif- THE CIRCULATION OP THK BLOOD. 271 The ventricles usually completely empty themselves of blood and maintain their systolic contraction even after this has been effected. The contraction of the heart, which really begins in the great veins near their junction with the auri- cles (that do not fully empty themselves), is at once fol- lowed up by the auricular and ventricular contraction, the whole constituting one long peristaltic wave. Then follows the cardiac pause, which is of longer duration than the entire systole. When the heart contracts it hardens, owing to closing on a non-compremible fluid dammed back within its walls by resist- ance a fronte. At the same time ihe hand placed on the chest- walls over the heart is sensible of the cardiac impulse, owing to what ban just been mentioned. The systole of Uie chambers of the heart gives rise to a first and a second sound, so called, caused by several events combined, in which, however, the ten- sion of Uie valves must take a prbminent share. The work of the heart is dependent on the quantity of blood it ejects and the pressure against which it acts. The pulse is an elevation of the arterial wall, occurring with each heart-beat, in conse- quence of the passage of a wave over the general blood-stream. There is a distention of the entire arterial system in every direc- tion. The pul
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1890, bookyear1890
