998 



A MANUAL OF ANATOMY 



returned from the lungs to the left auricle by the pulmonary veins. 

 By far the greater part of the right ventricular blood, however, 

 enters the ductus arteriosus, and is conveyed by it to the aorta 

 immediately beyond the origin of the left subclavian artery. None 

 of this blood, therefore, enters the three great vessels which spring 

 from the arch of the aorta. The whole of it descends in the de- 

 scending thoracic and abdominal portions of the aorta, and has a 



Internal Jugular Vein 



Subclavian Vessels^'fQ'^: 



Superior Vena Cava 



Foramen Ovale 

 Orifice of Inferior Vena Cava 



Eustachian Valve 

 Inferior Vena Cava 



Hepatic Veins zzT^ 



Inferior Vena Cava 

 Aorta 



Common Iliac Vein 

 External Iliac Vessels 



Common Carotid Artery 



'^^Wi^ Ductus Arteriosus 



, Pulmonary Artery 



Left Auricle 



Left Ventricle 

 . Right Ventricle 



Ductus Venosus 



Left Branch of Vena Portae 



Right Branch of 



. ^ Vena Portse 



Vena Poitae 



Umbilical Vein 



. . Umbilicus 



- Umbilical Arteries 

 -. Umbilical Vein 



l^^mbilical Cord 



Hypogastric Arteries 



Fig. 4n. — Diagram of the Organs of Circulation in the Fcetus 

 (The arrows indicate the course of the Circulation). 



twofold destination. Part of it is distributed to the abdominal 

 and pelvic viscera, and the lower limbs, whence it is returned by 

 the vena portae and inferior vena cava ; but the greater part of it 

 is conveyed out of the body of the fcKtus to the placenta by means 

 of the hypogastric and umbilical arteries. Having been purified 

 in the placenta, it is returned thence by the umbilical vein into 

 the body of the foetus. This placental blood, as stated, reaches 

 the inferior vena cava in two ways, partly directly by means of the 



