ANSC 220 Lecture Notes - Lecture 19: Inferior Vena Cava, Ductus Arteriosus, Ductus Venosus
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Notes on fetal circulation: general: the fetus is a parasitic growth which derives its protection and substance from its mother, umbilical vein. 1. returns o2-rich blood to the fetus, entering the fetal body via the naval (umbilicus) 2. in most species, this blood is taken to the fetal liver where nutrients are partly extracted and stored. 3. blood leaves the fetal liver by way of the hepatic vein which in turn enters the caudal vena cava. 4. in cattle, some blood bypasses the liver via the ductus venosus: fetal heart. 1. blood enters the right atrium by way of the caudal and cranial vena cava and coronary veins (sinus) 2. this blood may go to the right ventricle or to the left atrium by way of a hole (foramen ovale) located in the atrial septum. 3. blood leaves the right ventricle by way of the pulmonary artery leading to the nonfunctional fetal lungs.