Unit 5 Notes: Small Intestine Details!

(1) Regions Duodenum: (First Chamber) Approximately 10in long Jejunum: (Middle Section) Approximately 7-8ft long Ileum: (Last Section) Approximately 12ft long

(2) Inside the Duodenum Secretes Bile, Pancreatic Juice & Bicarbonate: Bile = Yellow-green solution produced by the liver, stored in the gallbladder. Pancreatic Juice = Solution produced by the pancreas, stored in the pancreas. Bicarbonate = pH balancing compound found in the blood. Metabolize all remaining proteins and lipids.

(3) About Bile… Produced by liver, Stored by Gallbladder Contains: Bile Salts Waste Pigments (bilirubin) Cholesterol & Phospholipids Function: Emulsify lipids so that they are dispersed throughout water, and can be easily absorbed.

(4) About Pancreatic Juice… Produced by pancreas Contains: Carboxypeptidase (Protein Enzyme) Chymotrypsin (Protein Enzyme) Amylase (Carbohydrate Enzyme) Lipases (Lipid Enzymes) Nucleases (Nucleic Acid Enzymes) Function: Metabolize all remaining biomolecules.

(5) Releasing Bile & Pancreatic Juice Lipids & Proteins  Release of CCK (cholecystokinin) into bloodstream CCK stimulates release of bile + pancreatic juice Out Sphincter of Oddi

(6) About Bicarbonate… HCO3 Used to maintain pH balance within cells (and water systems). Neutralizes acidity of chyme coming from stomach Secreted from Brunner’s Glands along Duodenum Walls.

(7) In The Jejunum & Ileum Smooth Muscle with millions of microvilli: Microvilli Absorb Nutrients Nutrients directly deposited in blood stream Folds in between are called “Crypts of Lieberkuhn” Crypts of Lieberkuhn: Secrete Lysozymes to eliminate any foreign bacterial cells Secrete Muccin to lubricate and dissolve remaining food stuff

(8) Large Intestine Regions Cecum = 1st Chamber Ascending Colon = Upwards Transverse Colon = Across Descending Colon = Downwards Rectum & Anus

(9) That Appendix Sits beneath cecum Often collects waste and bacteria  Appendicitis Functions: Produces white blood cells and antibodies for immunity. Used to serve a role in cellulose digestion.

(10) Passing Through the Colon… Waste slowly moves through Large Intestine. Total Length = 1.5-2m long Water reabsorbed through microvilli. Result = Solidified waste mass (Feces)

(11) The Rectum & Anus Rectum = Inside part Anus = Outside part = Butthole Mechanism: Remaining waste drops first into rectum Lands on top of Involuntary Sphincter Opens w/pressure Lands on top of Voluntary Sphincter Made of Skeletal Muscle that you control