. A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative. THE CIRCULATION OF THE BLOOD. 269 be less under nervous control, but it certainly is least dependent on the nervous system, and has the greatest automaticity. The law of rhythm in organic nature finds some of its most €!vident exemplifications ia the circulation. Most of the rhythms are com- pound, one being blended with or su- perimposed on an- other. Even the ap- parent irregularities of the normal heart are rhythmical, such as the very marked slowing and ,oth
. A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine. Physiology, Comparative. THE CIRCULATION OF THE BLOOD. 269 be less under nervous control, but it certainly is least dependent on the nervous system, and has the greatest automaticity. The law of rhythm in organic nature finds some of its most €!vident exemplifications ia the circulation. Most of the rhythms are com- pound, one being blended with or su- perimposed on an- other. Even the ap- parent irregularities of the normal heart are rhythmical, such as the very marked slowing and ,other changes accompany- ing expiration, espe- cially in some ani- mals. We trust we have made it evident that the greatest allow- ance must be made for the animal group, and some even for the individual, in es- timating any one of the factors of the cir- culation. We know a good deal at present of cardiac physiology, but we do not know a physiology of " the heart" in the sense in which we understand that term to have been used till recently—i. e., we are not in a position to state the laws that apply to all forms of heart. Summary of the Physiology of the Cironlation.—In the mammal the circulatory apparatus forms a closed system con- sisting of a central pump or heart, arteries, capillaries, and veins. All the parts of the vascular system are elastic, but this property is most developed in the arteries. Since the tissue-lymph is prepared from the blood in the capillaries, it may be said that the whole circulatory system exists for these vessels. As a result of the action of an intermittent pump on elastic. Pia. 823.—yeins of the foot of the horse (after Chau- veau).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Mills, Wesley, 1847-1915. New York, Appleton
Size: 1370px × 1823px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthormillswes, bookcentury1800, bookdecade1890, bookyear1890
