Histology or Structure of the Gall Bladder
The gall bladder too has a histological structure like all the other organs. It presents from the usual outside inwards the four layers or coats namely the serous, perimuscular, muscular, and a mucous coat also.
The serous coat is nothing but the derivations of the peritoneal layer, thus all the places of the gall bladder covered with the peritoneum are under this, and covers them partially. It is actually not absolutely complete, and covers only the entire fundus and also some of the portions of the body as well as the neck.
The next layer or the perimuscular layer is the one which is consisting of thick layers of the tissues, connective in nature, along with the arteries, veins, nerves and also the lymphatics.
The third layer or the muscular layer is the layer of the smooth muscle fibers, which are not only smooth but also irregular in shape and are also found to be decussating in nature. These muscle fibres consist of the longitudinal oblique and also transverse fibres. These muscular layers also provide numerous spaces between their fibres which are filled up with the reticular, elastic or the collagenous fibres with the presence of fibroblasts also.
Now considering the mucous membrane of the gall bladder, we can see that these are devoid of the muscularis mucosae. These have the appearance of the comb of the honey, and also have the layer of the single columnar epithelium which is an aid to be absorptive in nature.
There is the absence of any glands in this layer, but there may be some types of mucus glands at the neck. The cystic duct has a mucous membrane that is said to be thrown into several folds known as the “spiral valve of duct”. There are the presence of three types of cells known as the pencil cells, tall columnar cells, and the basal cells.