Small Intestine

Most chemical digestion takes place here Absorb nutrients Other organs assist 1 st part of the SI is the duodenum

Small Intestine Villi – tiny fingerlike structures cover the inner surface of small intestine; absorbs nutrients into the blood and carry through the body

3 organs assist: (these substances go to the duodenum) 1.Liver -produces bile 2.Gall bladder -stores bile -sends bile to the SI -bile breaks down fat droplets 3.Pancreas -produces pancreatic juice & sends to the SI -has enzymes for starch and protein -begins chemical digestion of fat

Liver Gall bladder Duodenum Pancreas Stomach

The small intestine The small intestine has 3 enzymes to complete digestion: Amylase breaks starch down into glucose. Amylase breaks starch down into glucose. Protease breaks protein down into amino acids. Protease breaks protein down into amino acids. Lipase breaks fats down into fatty acids and glycerol Lipase breaks fats down into fatty acids and glycerol

Small Intestine has a large surface area (increases absorption) The tube is over 6 meters long The inner wall of the tube has bends in it The wall is covered in villi (small finger- like structures) Outer wall Inner wall Pathway for Food

Absorption 2: Villi Outer wall Inner wall Pathway for Food