12 Amphibian Ventral Aorta & Aortic Arches Urodeles have ductus caroticus present meaning blood in arch three can go cranial or caudalAnurans have no ductus caroticus, so that blood in third aortic arch can only go towards the head
14 Reptile Ventral Aorta & Aortic Arches Two aortic trunks from conus arteriosus – sends blood to arch 3 and 4One pulmonary trunk from conus arteriosus – sends blood to 6th aortic archOtherwise similar to amphibians
16 Birds & Mammals Ventral Aorta & Aortic Arches One aortic trunk that sends blood to arches 3 and 4One pulmonary trunk sends blood to arch 6Fourth Aortic ArchRight side stays in birdsLeft side stays in mammalsRight side of 4th arch becomes subclavian A. in mammals
38 Cardinal Stream Amniotes Postcava (=inferior vena cava = caudal vena cava)Takes the place of the Posterior Cardinal VeinDrains some of hindlimbs in crocodiles, all of hindlimbs in mammals and eventually drains most of trunk and tail, in addition to hind limbs
49 Key PointsTrace the blood flow from the brain of a crocodile to the sinus venosus.
50 Renal Portal StreamA Portal is a vein that begins and ends in a capillary bedFish – drains tail to kidneyAmphibians – drains hindlimbs to kidneysReptiles and birds – bypasses kidneys and goes to postcavaMammals –not present
62 Abdominal Stream Mammals In fetus only Umbilical Vein becomes the round ligament of the liver in the adultDuctus venosus is a bypass of the liver and becomes the ligament venosum as a remnant in the adult