histology of gall bladder
Post on 25-May-2015
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DESCRIPTIONHistology of Gall bladder and its formation which consist of mainly 3 layers which they are: - Mucosa - Muscularis / Fibromuscular layer - Serosa / Adventitia And you must note that there is no Muscularis mucosa & Submucosa inside Gall bladder... Prepared by Nahry Omer Muhammad, University of Sulaimany/Collage of Medicine
- 1. Small, pear-shaped organ situated on the inferior aspect of the liver. 10 cm in length and 4 cm in cross-section.
2. Consists of: - Mucosa - Muscularis / Fibromuscular layer - Serosa / Adventitia 3. Mucosa: It includes the lining epithelium of simple columnar variety. Lamina propria rich in elastic fibers and blood vessels. Presence of microvilli gives brush border appearance to the epithelium under light microscope, Which facilitates absorption of water. Mucosa thrown into small folds when the bladder is empty. 4. Muscularis: This layer consists of circularly arranged smooth muscle fibers intermixed with connective tissue rich in elastic fibers. the neck of the gallbladder, the lamina propria houses simple tubuloalveolar glands, which produce a small amount of mucus. Lamina Propria Muscularis Layer Loose connective tissue 5. Serosa/Adventitia: Fundus and lower surface of body of gall bladder is covered by peritoneum. Upper surface is attached to the fossa for gall bladder by means of connective tissue. 6. There is no: Muscularis mucosa & Submucosa. 7. The main function of the gallbladder is to store bile, concentrate it by absorbing its water, and release it when necessary into the digestive tract. This process depends on an active sodium-transporting mechanism in the gallbladder's epithelium. Water absorption is an osmotic consequence of the sodium pump. Contraction of the smooth muscle of the gallbladder is induced by (cholecystokinin), a hormone produced by enteroendocrine cells located in the epithelial lining of the small intestine. Release of cholecystokinin is, in turn, stimulated by the presence of dietary fats in the small intestine. 8. Gall bladder and Liver are innervated by both sympathetic and parasympathetic Fibers. Nerves enter the liver through porta hepatis and ramify through the liver in the portal canals along with members of portal triad. Sympathetic fibers innervate blood vessels, while parasympathetic fibers innervate Large ducts and possibly blood vessels.