Small Intestine Research Paper

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The small intestine consists of three divisions: The duodenum is the uppermost division and the part to which the pyloric end of the stomach attaches. it is about 25 cm (10 inches) long and is shaped roughly like the letter C. The name duodenum , meaning " 12 fingerbreadths," refers to the short length of this intestinal division. The duodenum becomes jejunum at the point where the tube turns abruptly forward and downward . The jejunal portion continues for approximately the next 2.5 m (8 feet) , at the end of which it becomes the iluem, but without any clear line of demarcation between the two divisions. The ileum is about 3.5 m (12 feet) long.
Colon:The colon , which itself has four divisions ( the ascending, transverse, descending , and
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it consists of simple columnar epithelium overlying a lamina propria and a thin layer of smooth muscle layer of smooth muscle called the muscularis mucosa. The mucosa contains a collection of lymphoid nodules called mucosal associated lymphoid tissue (MALT) , mucus - secreting goblet cells, and other glands that secrete products such as hydro hydrochloric acid and enzymes. The mucosa is generally covered with a layer of mucus that helps protect the underlying epithelium from the effects of the acid and digestive …show more content…
these two layers contract alternately . To produce the rhythmic contractions of Peristalsis. The muscularis externa of the stomach has three layers of smooth muscle, with an additional oblique layer. Serosa: The outer connective tissue layer is called the serosa, which is partially composed of the visceral peritoneum,throughout much of the alimentary canal. it is also known as the adventitia.

Acinar cells:The exocrine cells of the pancreas, called acinar cells, produce and secrete pancreatic juice (digestive enzymes, bicarbonate, and water) into ducts.

Pancreatic islets: The endocrine cells of the pancreas, called pancreatic islets or islets of Langerhans, secrete hormones such as insulin into the bloodstream. they are visible a small, Circle the groups of cells that stain less darkly than the surrounding acinar cells.

Liver lobules:The liver consist of hepatocytes organized into hexagonal plates of cells called liver lobules. At the end of each lobule is a central vein that will eventually drain into the hepatic veins. at each of the six corners of a liver lobule we find three small vessels collectively called portal triads. The three vessels are:
1. bile duct
2. Portal vein
3. hepatic

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