Describe the basic tissue structure of these digestive accessory organs pancreas, salivary glands, liver and gallbladder

Pancreas, salivary glands, liver and gall bladder are accessory organs which take part in the digestive process and each of them has important roles that they play.
1. Pancreas: pancreas participates in digestion by secreting pancreatic juice which is a mixture of enzymes, water, buffers and electorlytes. Pancreatic juice is produced by the acinar and the epithelia cells. During digestion, the juice moves through the pancreatic duct into the bile duct and empty its content into the small intestines. At the small intestines, the pancreatic juice functions by buffing the stomach acid. It also breaks down fats, protein and carbohydrates.
2. Salivary glands: the major purpose of saliva is to hydrate food and begin the process of chemical digestion. There are six salivary gland in the oral cavity, these glands secrete saliva. Saliva moves out of the glands into the oral cavity via ducts. Saliva is composed of water [99%], proteins and enzymes.
3. Liver: the liver secretes bile which carry out the emulsification of fats. The liver produces bile on a continual basis, the bile flow out of the liver via the left and the right hepatic ducts into the common hepatic duct and finally into the small intestine. But when the bile is not yet needed it is moved into the gall bladder for storage.
4. Gall bladder: the principal function of gall bladder is storage of bile. The gall bladder is a green pear shaped sac, it is about 10 centimeters long. The gall bladder releases the bile into the small intestines as at when needed.