. A laboratory manual and text-book of embryology. Embryology. LATERAL DISSECTION OF THE VISCERA 109 The anterior cardinal veins are formed by the plexus of veins on each side of the head which are drained by two trunks (Figs. 98 and 99). These extend caudad and lie lateral to the ventral portion of the myelencephalon. Each an- terior cardinal vein receives branches from the sides of the myelencephalon, then curves ventrad, is joined by the linguo-jacial vein from the branchial arches and at once unites with the posterior cardinal of the same side to form the common cardinal vein. This, as we
. A laboratory manual and text-book of embryology. Embryology. LATERAL DISSECTION OF THE VISCERA 109 The anterior cardinal veins are formed by the plexus of veins on each side of the head which are drained by two trunks (Figs. 98 and 99). These extend caudad and lie lateral to the ventral portion of the myelencephalon. Each an- terior cardinal vein receives branches from the sides of the myelencephalon, then curves ventrad, is joined by the linguo-jacial vein from the branchial arches and at once unites with the posterior cardinal of the same side to form the common cardinal vein. This, as we have seen, opens into the sinus venosus. Spinal cord Anterior cardinal vein Cervical sinus Pericardial cavity R. common cardinal vein Post, cardinal vein Esophagus Large venous sinusoid Liver A utcrior limb bud Inf. vena, | Post. Post, cardinal vein Mcsonepliros {cut surface) R. subcardinal vein Venous sinusoid on dorsum of mesonephros Dorsal aorta Nolochord. Nolochord Pharynx Trachea L. common cardinal vein Lung Liver Stomach {cut edge) Omental bursa Mesogastrium Mesonephros {cut surface) Capillary anastomosis between subcardinal veins Vitelline artery in dorsal mesentery Capillary anastomosis between subcardinal veins Venous sinusoid on dorsum of mesonephros Spina! cord Fig. 98.—Reconstruction of the cardinal and subcardinal veins of a 6 mm. pig embryo showing the early development of the inferior vena cava (K. L. Yehe). The posterior cardinal veins develop on each side in the mesonephric ridge, dorso-lateral to the mesonephros (Figs. 98 and 99). Running cephalad, they join the anterior cardinal veins. When the mesonephroi become prominent, as at this stage, the middle third of each posterior cardinal is broken up into sinusoids (Minot). Sinusoids extend from the posterior cardinal vein ventrally around both the lateral and medial surfaces of the mesonephros. The median sinusoids anastomose longitudinally and form the subcardinal veins, right and left. The. Please no
Size: 1135px × 2202px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
