Anatomy of the Gallbladder

The gallbladder is a hollow organ that sits beneath the liver and stores bile made in the liver. In adults, the gallbladder measures approximately eight centimeters (3.1 in) in length and four centimeters (1.6 in) in diameter when fully distended. 

The gallbladder is divided into three sections: 

1. The fundus.
2. The body.
3. The neck. 

The neck tapers and connects to the biliary tree via the cystic duct, which then joins the common hepatic duct to become the common bile duct. At the neck of the gallbladder is a mucosal fold where gallstones commonly get stuck.

The gallbladder, labeled

An illustration of the gallbladder from Gray's Anatomy with each section labeled.

An illustration of the gallbladder from Gray's Anatomy with with its sections labeled: fundus, body, and neck.

Layers of the Gallbladder

There are several different layers of the gallbladder: the mucosa (epithelium and lamina propria), the muscularis, the perimuscular, and the serosa.

• The epithelium is a thin sheet of cells that is closest to the inside of the gallbladder. 
• The lamina propria is a thin layer of loose connective tissue, which together with the epithelium, forms the mucosa. 
• The muscularis is a layer of smooth muscular tissue that helps the gallbladder contract and squirt its bile into the bile duct. 
• The perimuscular (meaning around the muscle) is a fibrous connective tissue layer that surrounds the muscularis. 
• The serosa is a smooth membrane that is the outer covering of the gallbladder.

Layers of the gallbladder

A micrograph of the layers of a gallbladder.

A micrograph of the layers of a gallbladder: the mucosa (epithelium and lamina propria), the muscularis, the perimuscular, and the serosa.