. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. THE CIBCULATION OF THE BLOOD. 289 111 led on a single d. in the light of 8 the result of are the snd- d the contrac- he account the itself through e idea that in ified in quality all during sys- mlmonary and d suppose that >rtic valves and ressed together, ui in the right; pressure of
. A text-book of animal physiology [microform] : with introductory chapters on general biology and a full treatment of reproduction, for students of human and comparative (veterinary) medicine and of general biology. Physiology, Comparative; Veterinary physiology; Physiologie comparée; Physiologie vétérinaire. THE CIBCULATION OF THE BLOOD. 289 111 led on a single d. in the light of 8 the result of are the snd- d the contrac- he account the itself through e idea that in ified in quality all during sys- mlmonary and d suppose that >rtic valves and ressed together, ui in the right; pressure of the at of the right, ) maximum and pressure within roximately. As bat it has been 140 mm. of mer- 60, and for the ter not quite so ate to the maxi- t; and the press- be negative. By negative pressure for the left ven- 12 to—7 mm. for f this diminished aovements; and, ' that ordinarily, 1 force, the neg^ is comparatively )gative pressure, irt's diastole, has Some find it difficult to understand how the heart after sys- tole may regain its original form apart from the assistance of diastolic muscles, which are assumed to act so as to antagonize those causing systole. Others think the elasticity of the heart's muscle sufficient of itself to account for the organ's return to its original form. But there is surely a misconception involved in both of these views. If small portions of the heart of the frog, tortoise, or other cold-blooded animal, just removed from the body, be observed under a microscope it will be seen that they alternately con- tract and relax. Now, it is only necessary to suppose that the relaxation of the heart is complete after each systole, to under- stand how even an empty heart regains its diastolic form. That there should be a negative pressure in, say, the left ventricle, follows naturally enough from the fact that not only are the contents of the ventricle expelled with great sudden- ness, but that its walls remain (see Figa 210 and 214) pressed toget
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Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1880, bookyear1889
