Anatomical and microscopic evaluation of the liver in migratory shoveler ducks (Spatula clypeata): A multi-modal study using gross anatomy, vascular casting, morphometric analysis, and histochemistry techniques.

This study was carried out to explore the anatomical and microscopic features of the liver in shoveler ducks using gross and vascular anatomical casting, morphometric analysis, and histochemical techniques. This study was applied to twenty-six adult ducks. The liver, located in the middle-third of the coelomic cavity, had a larger right lobe and no further subdivided lobes, housing the gallbladder in a cystic fossa on the right lobe's visceral surface. The liver's venous drainage occurs through the hepatic veins (right, left, and middle) along with accessory and umbilical veins. The intrahepatic portal system consisted of two portal veins: left and right. Hepatic arterial supply originated from the celiac artery, which divided into right and left branches for intrahepatic distribution. The right branch gave dorsal and ventral right hepatic arteries and continued as the right gastric artery, while the left branch formed the left gastric artery and gave left hepatic arteries. Histologically, the liver was surrounded by a thick connective tissue (CT) capsule with poorly defined lobules and polygonal hepatocytes around central veins. Hepatocytes expanded toward the subscapular region with few fat globules within the cytoplasm, displaying a larger nucleus, and the sinusoids were filled with erythrocytes. Histochemical analysis revealed a strong positive reaction to the PAS stain. Densely packed collagen fibers were demonstrated by Masson's trichrome stain in the capsule, around large blood vessels, and bile ducts.