After completing this study unit, you will be able to:
- Explain the structure and function of the gallbladder.
- Describe the layers of the gallbladder wall and their components.
The gallbladder is a small, pear-shaped organ which is located beneath the liver. It functions to collect, store and concentrate bile received from the liver and expel it to the small intestine as needed for the emulsifcation of fats.
The wall of the gallbladder consists of a mucosa, muscular coat and serosa. The mucosa is formed by a layer of simple columnar epithelium (with microvillous border (cells =choleocystoctyes)) which concentrates the bile as well as secretes a protective mucus which protects the internal wall of the gallbladder. In a nondistended state, the mucosa forms distinct mucosal folds (rugae), between which are pocket-like mucosal crypts, or diverticula. The lamina propria mucosae, which underlies the epithelium, is composed of loose connective tissue.
The muscular coat consists of a single layer of randomly oriented smooth muscle, which functions to propel bile into the bile duct. Externally the gallbladder is surrounded by a serosa except where the gallbladder attaches to the liver; here the serosa is replaced by an adventitia (i.e. no mesothelial/peritoneal layer).
Take a closer look at the histological structure of the gallbladder in the gallery below.
Take a quiz
Reinforce and test your knowledge of the gallbladder with the following quiz.
If you would like to broaden the focus of your revision, try this customizable quiz on the histology of the digestive system and choose exactly which structures you wish to revise.