Gall Bladder

Prepared By: Nahry Omer Muhammad

Anatomy of Gall Bladder

• Small, pear-shaped organ situated on the inferior aspect of the liver.

• 10 cm in length and 4 cm in cross-section.

Histological Structure

Consists of:

- Mucosa

- Muscularis / Fibromuscular layer

- Serosa / Adventitia

Histological StructureMucosa:• 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.

Muscularis:

Histological Structure

• 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

Histological StructureSerosa/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.

Histological StructureThere is no:

Muscularis mucosa

&

Submucosa.

Function• 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.

Nerve supply

• 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.

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