Gallbladder
Stores and concentrates bile from the liver.~ Arteries: Cystic artery (a branch of the right hepatic artery)
Histology
~ Mucosa:~ Muscularis Mucosa:
~ Subserosa/Adventitia:
Chronic cholecystitis
Most often caused by gallstones, that leads to hyperkinesia. Hyperkinesia than leads to thickened muscularis (hypertrophy of the muscles), chronic inflammation and fibrosis in the subserosa. As gallstones are most often caused by increase biliary secreation of cholesterol, sometimes foamy histiocyte are formed in the lamina propria, which is a histiocytes (macrophage) with cytoplasm filled with tiny coarse vacuoles. You will also see Rokitansky-Aschoff sinuses, which are invaginations or protrusions of the gallbladder epithelia that can reach the either perimuscular or the subserosal connective tissue. This is caused by increased luminal pressure in the gallbladder and weakened muscular layer.
Acute cholecystitis
Is caused by blockage of the cystic duct, which is most often caused by stones but can also be caused by a tumor or even cocaine induced, though rare. This blockage of bile fluid can lead to inflammation and with time edema, which in turn can to vascular insufficiency which leads to wall ishemia and necrosis. Microscopically you will see edema and bleeding within the walls in combination with necrosis. At this stage you might see neutrofils in walls of the gallbladder. As this blockage of bile fluid leads to increased pressure within the gallbladder, that leads to stasis within veins, that leads to thombi formation in the small veins, which can even lead to fibrinoid necrosis. Sometimes gas-forming bacteria might infect the walls and cause air-bubbles, leading to emphysematous cholecystitis.
Cholesterolosis
Is when lipid accumulates in the walls of the gallbladder. Macrophages in the lamina propria then eat this lipid, turning them into foamy histiocytes (macrophages with cytoplasm filled with tiny coarse vacuoles). When there is a massiv accumulation of them sometimes polyps form, just a polypoid extrution of the lamina propria with these foamy little fellows.