Gallbladder and biliary system

Gallbladder and biliary system

Gall bladder and biliary system-

Gall bladder- It is a bag like structure in the shape of small pear which is located in the depression on lower layer of the right lobe of liver. Bile secreted from liver gathers here. It is about 10 cm in length and it can hold about 30 to 60 ml bile. Gall bladder is divided into three parts-

  1. Fundus.
  2. Body.
  3. Neck.

Gall bladder is made up of three layers-

1. External serum peritoneal layer.

2. Middle muscular layer.

3. Internal mucus membrane layer- This layer is disappeared in the layer of bile ducts. It is made up of epithelial cells in which musin secretes and it absorbs water soon. But, it is not able to absorb bile salts or bile pigments what is responsible for thickness of bile. When the gall bladder is empty, small wrinkles are appeared on its mucus membrane, which are disappeared after filling it.

Biliary system are made up of following parts-

  • Right and left hepatic ducts which are fused into common hepatic duct.
  • Gall bladder.
  • Cystic duct- It is about 4 cm long tube coming from gall bladder.
  • Common bile duct- It is made by the fusion of cystic duct and common hepatic duct.
  • Common bile duct and main pancreatic duct are connected at the opening of duodenum 10 cm away from pyloric door and forms hepetopancreatic amula or ampula of vater. The ampula passes slantly in the wall of duodenum and opens in duodenum passing through duodenal papilla. A sphincter is found on the exit point of common bile duct, called sphincter of boyden. Below it, there is a sphincter of oddi found. Sphincter of boyden is more strong and important comparison to sphincter of oddi. After 30 minutes of taking food or when fatty chime reaches in duodenum, the sphincter is become slower by the impact of hormone called cholicystokinin secreted by duodenum and the gall bladder is contracted, resulting bile gathered in gall bladder is reached in the duodenum. When digestion is stopped in duodenum, bile comes out from liver and goes on collecting in gall bladder.