Page 250 - Veterinary Histology of Domestic Mammals and Birds, 5th Edition

232 Veterinary Histology of Domestic Mammals and Birds

(Figures 10.74, 10.78 and 10.79). The Golgi apparatus is 10 days. These organelles contribute to metabolism by pro-
VetBooks.ir responsible for turnover and storage of substances under- viding energy. Enzymes associated with the mitochondrial
going intracellular transport. The membrane systems of membranes and matrix are involved in the cellular respira-
the Golgi apparatus participate in the formation of pro-
tory chain, the citric acid cycle and β-oxidation.
teoglycans and the manufacture of lipoproteins and bile Lysosomes are plentiful near the bile canaliculi (see
acids. In addition, they are the site of production of intra- below). These serve in intracellular digestion of exog-
cellular membranes and numerous enzymes (e.g. acid enous or endogenous substances. The breakdown of
phosphatases, thiaminopyrophosphatases). proteins, glycoproteins, glycolipids, nucleic acids and
Hepatocytes contain abundant, usually oval mitochon- lipids takes place within lysosomes. In addition, lysosomes
dria. Their number and structure vary according to the form residual bodies, or lipofuscin. Organelles referred
level of cellular activity (up to 3000 mitochondria per cell). to as microbodies contain metabolic enzymes including
Hepatocyte mitochondria are replaced approximately every oxidases, uricase and catalase.

10.76 Fine structure of a bile canaliculus (horse; x15,000).

10.77 Interlobular artery and vein supplying a liver lobule, and bile canaliculi passing between hepatocytes and
opening into bile ductules (schematic).

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