I 7 6 



NORMAL HISTOLOGY. 



neum is intimately attached, the subserous tissue is so reduced as to be practi- 

 cally wanting". In certain localities, conspicuously in the broad ligament of 

 the pelvis, the subserous tissue contains strands of unstriped muscle. 



The blood-vessels supplying the peritoneum itself are meagre in size 

 and number. The lymphatics include a superficial network beneath the 

 mesothelium and a deeper plexus of lymph-channels within the stroma. The 

 nerves include both medullated and nonmedullated fibres, the latter being 

 destined for the walls of the blood-vessels. The sensory fibres supplying the 

 parietal peritoneum in many cases are connected with lamellated corpuscles 

 and end-bulbs (Fig. 116). 



THE LIVER. 



The liver, the largest gland in the body, consists of very delicate gland- 

 ular tissue disposed around the ramifications of the portal vein. Developed 

 in the primitive anterior mesentery, its connective tissue (mesodermic) ele- 



Central vein 



"Blood -capillaries 



Portal vein 



Bile-capillaries 



Blood-capillarie 



ortal vein 



Sublobular branch of hepatic vein 



FIG. 219. Diagram of hepatic lobule; portions of surface and of transverse and longitudinal sections 

 of the lobule are represented. The branches of the portal vein are purple ; of the hepatic artery, red ; of 

 the hepatic veins, blue ; of bile-ducts, yellow ; the intralobular bile-canaliculi are black. 



ments have a common origin with the diaphragm, while its duct and glandular 

 elements are derived from a sprout from the duodenum. Hence the liver is an 

 outgrowth and appendage of the alimentary tube. Its peculiar shape is due 

 chiefly to the pressure of surrounding organs, since its tissue is so plastic as to be 

 moulded by them. The liver weighs from 1450-1750 gm., approximately 3-3^ 

 Ibs. , and in the adult contributes about one fortieth of the entire body weight. 

 In its fundamental arrangement, the liver corresponds to a highly 

 modified compound tubular gland. Early in foetal life, however, the termi- 

 nal divisions of the tubules unite to form networks, after which the tubular 



