. The comparative anatomy of the domesticated animals. Veterinary anatomy. 918 Fig. DIAGEAM OF THE CIR- CULATION AT THE COMMEMOEMENT OF THE FORMATION OF THE PLACENTA : SEEN FEOM THE FRONT. a, Venous sinus re- ceiving all the sys- temic veins; 6, Eight auricle ; 6', Left auricle; c, Eight ventricle ; c', Left ventricle; d, Bulbus aorticus, subdividing into, <?, e\ e", Bran- chial branches; /,/', Arterial trunks formed by their con- fluence ; g, g', Vena azygos superior; h^ h', Confluence of the superior and inferior azygos; y, Vena cava inferior; k, k', Vena azygos inferior; m, De
. The comparative anatomy of the domesticated animals. Veterinary anatomy. 918 Fig. DIAGEAM OF THE CIR- CULATION AT THE COMMEMOEMENT OF THE FORMATION OF THE PLACENTA : SEEN FEOM THE FRONT. a, Venous sinus re- ceiving all the sys- temic veins; 6, Eight auricle ; 6', Left auricle; c, Eight ventricle ; c', Left ventricle; d, Bulbus aorticus, subdividing into, <?, e\ e", Bran- chial branches; /,/', Arterial trunks formed by their con- fluence ; g, g', Vena azygos superior; h^ h', Confluence of the superior and inferior azygos; y, Vena cava inferior; k, k', Vena azygos inferior; m, Descending aorta; n, n, Umbilical arte- ries proceeding from it; 0, o'. Umbilical veins; q, Omphalo- mesenteric vein ; r, vesicle, t; v, Ductus EMBMYOLOGY. by the ductus arteriosus. To sum up, tte foetus never receives pure arterial blood into its organs, this being always mingled witb venous blood, the mixture taking place at several points : 1, By the foramen of Botal; 2, In the aorta by the ductus arteriosus; 3, In the liver by the ductus. venosus. The head and neck are the parts which receive the purest arterial blood, a fact which explains the predominance of the anterior over the posterior portion of the body of the foetus. At birth, the conditions of existence being suddenly changed, marked modifications take place in the cir- culatory apparatus. The lungs become the organs of respiration, and rapidly increase in capacity; the pul- monary artery dilates to give passage to the blood that flows to them; while the ductus arteriosus is obliterated, in order to isolate the arterial from the venous blood. This separation of the two fluids also takes place in the liver by the atrophy of the ductus venosus, and in the heart by the occlusion of the foramen of Botal; though, according to M. Goubaux, that orifice frequently remains open in young animals. Its persistence has also been noted in the human adult. Notwithstanding the pre- sence of this foramen, the circulation cannot be m
Size: 813px × 3073px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorchauveauaauguste18271, bookcentury1800, bookdecade1880
