8o8 



A MANUAL OF ANATOMY 



cells. The liver thus consists originally of intricate reticula of solid cellular 

 trabecul'S, or hepatic cylinders, disposed around the vitelline and umbilical veins. 



As the liver increases in size it projects downwards, carrying with it the 

 lower layer of the septum transversum, which forms its capsule and connective 

 tissue. The organ now lies between the two layers of the ventral or gastro- 

 duodenal mesentery, which gives rise to — (i) the falciform ligament; (2) the 

 posterior or coronary ligament; and (3) the gastro-hepatic or small omentum. 



About the middle of intra-uterine life the liver occupies a large part of the 

 abdominal cavity, and the right and left lobes are of equal size. In the latter 

 half of intra-uterine life, however, the right lobe gradually attains greater 

 size than the left. About the period of birth the liver extends almost as low 

 as the umbilicus. After birth it undergoes diminution in size, the circulation 

 of placental blood through it, by the umbilical vein, having been permanently 

 arrested at birth. 



At an early period in its development the liver presents four lobes — two 

 vitelline and two umbilical. The vitelline lobes represent the parts which are 

 developed around the vitelline veins, whilst the umbilical lobes are developed 

 around the umbilical veins. As, however, development proceeds the lobar 

 condition characteristic of the full-grown liver is gradually assumed. 



Neck 



Cystic Dact and 

 Valves of Heister 



Body of Gall-bladder 



Right Hepatic Duct 



-•Left Hepatic Duct 

 '^ Common Hepatic Duct 



Ductus Communis 

 Choledochus 



^^ ~- Pancreatic Duct (Duct of Wirsung) 

 ~"^- Ampulla of Vater 

 Duodenum (2nd part) 



Fig. 347, — ^The Excretory Apparatus of the Liver. 



Structure of the Gall-bladder.— The wall of the gall-bladder is 

 composed of three coats — serous, fibro- muscular, and mucous. 



The serous coat is formed by the peritoneum, and is usually incom- 

 plete, being confined to the inferior and lateral surfaces. Some- 

 times, however, the peritoneum completely surrounds the organ, 

 and attaches its superior surface to the cystic fossa of the liver by 

 a ligamentous fold. 



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