Anatomy of Liver and Radiographic Study on Hepatic Duct in a South African Ostrich Struthio camelus australis

Abstract

The South African Ostrich Struthio camelus australis, an acarinate flightless ratite bird, native to the African continent has been introduced in many countries including India in the recent past for meat as well as egg purpose. Although this largest extant bird is gaining popularity globally, the functional anatomy of this majestic giant has received relatively less attention. The liver, the largest gland in the body of an Ostrich (weighing approximately 1.5-2 Kg) is also the heaviest among all the birds. The Ostrich lacks gall bladder and thus, the bile needs to be produced continuously as in the case of certain mammals like horses and elephants. The present study aimed to investigate the gross morphological and radiographic characteristics of the liver of the Ostrich. The liver was divisible into two primary lobes: an undivided right lobe and a divided left lobe. The later consisted of dorso-cranial, intermediate, and ventro-caudal lobes. Notably, the ventro-caudal lobe was observed as the largest, while the intermediate lobe was the smallest. The right lobe, larger than the left, was connected to later by a thick isthmus at its cranial extremity. Using barium sulphate injection and positive contrast radiography, the intrahepatic course of the hepatic duct was visualized, revealing two distinct divisions and tributaries thereof for draining bile from the right and left lobes, respectively. A radiographic study of the intrahepatic course of the hepatic duct revealed a single right intralobar duct and two left intralobar ducts. The distinct isthmus was drained by the branch of the left intralobar duct.