Histology of Gallbladder has several layers which are as follows.
A thin sheet of cells near the inside of gallbladder named as Epithelium.
A layer of loose connective tissues named as Lamina Propria. This along with Epithelium forms Mucosa.
Muscularis, it is a layer of plain muscular tissue that to contract Gallbladder and squirting its bile into the bile duct.
Perimuscular Fibrous Tissue is another layer of connective tissue.
The outer layer covering the Gallbladder is formed from Peritoneum which is the lining of Abdominal Cavity. This layer is called Serosa.
Gallbladder unlike Intestinal Tract doesn’t have Muscularis Mucosae (a layer of smooth muscles found in most region of Gastrointestinal Tract).