Light micrographs of the liver. Low magnification light micrographs of hepatic lobule in livers. (a) A portal triad (P) is seen in the hepatic lobule, and consists of both hepatocytes and sinusoidal blood capillary networks, in which hepatocyte-sinusoidal structures (HS) are formed. Montane brown frog (Rana ornativentris). (b) High magnification light micrograph of portal triad. A portal space with its characteristic small hepatic artery (A) portal vein (V), lymph vessel (L), and bile duct (B) is surrounded by connective tissue. Japanese giant salamanders (Andrias japonicus). High magnification light micrographs of hepatocyte-sinusoidal structures in livers. (c) Several-cell-thick plate type. The hepatocyte lining is multi-layered. Hepatic sinusoids (arrows) are narrow and short tortuous capillaries. Hepatocytes are rounded, and have a small rounded nucleus. Clouded salamander (Hyobius nebulosus). (d) Two-cell-thick plate type. T he hepatocyte lining is double-layered. Sinusoidal capillaries (arrows) are narrow and irregularly shaped sinusoids appearing throughout the interstices between the hepatic plates. Hepatocytes are polyhedral or rounded and have a rounded nucleus. Amber-colored salamander (Hynobius stejnegeri). (e) One-cell-thick plate type. The hepatocyte lining is simple-layered. Hepatic sinusoids (arrows) are enlarged with straight capillaries. Hepatocytes are polyhedral and have a rounded nucleus. Montane brown frog (Rana ornativentris). (f) Genus Hynobius are of the combined several- and two-cell-thick plate type. Hepatocytes are rounded and have a large nucleus. Spotted salamander (Hynobius naevius). (g) Another genus of the Hynobius group is of the combined one- and two-cell-thick plate type. Hepatocytes are square and have a large nucleus. Hida salamander (Hynobius kimurae). (h) In the order Gymnophiona, the parenchyma arrangement is one-cell-thick plate type. Sinusoidal capillaries are enlarged. Hepatocytes are square, and have a large rounded large nucleus. Cayenne caecilian (Typhlonectes sp.). (i) In the order Anura, the parenchyma arrangement is the one-cell-thick plate type. Sinusoidal capillaries are enlarged. Hepatocytes are square and polyhedral and have a small rounded nucleus. Schlegel’s green frog (Rhacophorus schlegelii). Scale bars = 100 μm.