To add: diverticulosis, colon cancer, barium enema
11u bio ani 06
The Intestines and Accessory Organs
The Intestines The small intestines are narrow (~2.5 cm wide), but up to ~630 cm long. There are 3 sections: - First ~30 cm: Duodenum - Next ~250 cm: Jejunum - Last ~350 cm: Ileum Jejunum Duodenum Ileum
The Duodenum 1) Chemical digestion continues in the duodenum. Carbohydrate, lipid, and protein digestion is almost completed.
The Duodenum The pancreas and the gall bladder are connected to the duodenum via ducts.
The Duodenum The gall bladder, pancreas, and liver are called accessory organs because food does not actually pass through them.
The Pancreas The pancreas is about 15 cm long and releases enzymes into the duodenum. These include: - proteases - carbohydrases - lipases - nucleases
The Pancreas Pancreatic juice also contains sodium bicarbonate to raise the pH of the chyme.
The Liver and Gall Bladder The liver makes bile (gall) : a substance that is able to attach to lipid globules and emulsify (separate) them into separate molecules. Extracted bile.
The Liver and Gall Bladder This emulsification enhances the activity of lipases by increasing the lipid surface area. It contains cholesterol and bile salts.
The Liver and Gall Bladder The gall bladder stores bile until it is needed. To duodenum From liver
The Liver and Gall Bladder Gall stones occur when the bile crystallizes inside the gall bladder. They may cause obstruction of the bile duct.
The Liver and Gall Bladder The secretions of the pancreas and gall bladder are controlled by hormones .
The Liver and Gall Bladder Secretin from the duodenum makes the pancreas secrete sodium bicarbonate and the gall bladder to secrete bile.
The Liver and Gall Bladder Cholecystokinen (CCK) from the duodenum make the pancreas secrete enzymes and the gall bladder to secrete bile. Also slows down the stomach.
The Jejunum 2) Digestion is completed in the jejunum and absorption is just beginning. This is the transitional section. Chyme has become chyle . Jejunum
The Jejunum Peptidases and disaccharidases are completing dipeptide and disaccharide digestion here.
The Jejunum Lined with longitudinal and circular muscles to perform peristalsis . Has villi.
The Ileum 3) Some absorption of nutrients takes place in the jejunum, but absorption primarily occurs in the ileum.
Absorption The surfaces of the jejunum and ileum that perform absorption are designed for maximum surface area for food to pass by.
The Appendix Attached to the cecum is the vestigial appendix, which is believed to have once held bacteria for cellulose digestion. Appendicitis is the inflammation of the appendix, which must then be removed.