VAN 211: Veterinary Histology and Embryology (2+2)

GALL BLADDER

• It is a diverticulum of the hepatic duct developmentally to store bile It is absent in horse, elephant, rat and pigeon.
• Duct of gall bladder is called cystic duct, which unites with hepatic duct and forms the bile duct.
• Structure:
• Similar to large bile ducts. The wall consists of the following layers.
• Mucosa consisting of a surface epithelium and lamina propria,
• A layer of smooth muscle;
• A perimuscular connective tissue and
• A serous layer.
• Mucosa is thrown into folds. Epithelium consists of tall columnar (which has goblet cell in the Ox.)
• The lamina propria contains lymph nodules and glands. The carnivores have few glands while ruminants have many mucous and serous glands.
• The muscular layer consists of smooth muscle running in different directions, circular and oblique, with the circular predominating, in some place regular inner circular and outer longitudinal layers can be seen.
• The perimuscular connective tissue layer is usually thick and outside this is the subserous layer of connective tissue containing blood vessels and nerves. On its free surface it is not attached to the liver, it is covered by serosa (Peritoneum).