Gall Bladder

#115 Gallbladder, (H&E)

The gall bladder is a distensible blind pouch that receives dilute bile from the liver. Bile is concentrated within the organ. It is released under stimulation from the small intestine. What hormone is responsible for this? The highly convoluted mucosa is lined with simple columnar epithelium. Note the microvillus border. There are numerous dilated blood vessels in the lamina propria. Unlike other parts of the gastrointestinal tract, there is no muscularis mucosae. The muscularis externa contains elastic and collagen fibers among the bands of irregularly arranged smooth muscle. Externally there is dense, irregularly arranged connective tissue.