Small Intestine

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Small Intestine Notes

Small intestine- digestive organ in which chyme from the stomach is flooded with enzymes and digestive fluids.
As chyme is pushed through the pyloric valve, it enters the duodenum. Duodenum- first part of the small intestine.
Chyme is then flooded with a variety of enzymes and other digestive fluids that break down additional food molecules. These enzymes and digestive fluids come from the intestine itself, the pancreas, and the liver. Enzymes produced by intestinal glands attack complex carbohydrates, breaking them down into their component sugars.

Pancreas- organ that is both an exocrine gland and an endocrine gland; secretes digestive fluids and the hormones: insulin and glucagon. Has many glands which are stimulated to release their secretions which are called pancreatic fluid. Pancreatic fluid enters a duct that empties into the duodenum. Enzymes in pancreatic fluid are responsible for the digestion of carbohydrates, fats, and proteins.

Liver- large organ that lies above the stomach, secretes bile, and stores excess glucose in the form of glycogen. Can weigh up to 1500 grams
One job of liver is to secrete a yellow-brown liquid called bile.

Bile is stored in a small sac called the gallbladder.
Gallbladder- small sac in which bile is stored.
Weird thing- bile doesn't have enzymes.
However it does have cholesterol, colored pigments, and bile salts. Fats can't dissolve in water so they become large globules of fat. Bile salts break them into smaller droplets.
The entrance of food into the small intestine stimulates the release of bile from the liver through the bile duct into the duodenum.

The inside walls of the small intestine are folded to increase surface area. Walls resemble wall-to-wall carpeting because of projections called villi. Villus- folded projection that increases the surface area of the walls of the small intestine. Beneficial surface...
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