digestion in small intestine

point in digestion

• all nutrients are chemically broken down into their basic units

• physical digestion also occurs

• chemical digestion involves 3 fluids, secretion stimulated by chyme

intestinal juice

• produced and secreted by epithelial cells

• contains carbohydrates (maltose, sucrose and lactose), proteases (peptidases) and lipases

pancreatic juice

• produced by pancreas

• enters duodenum via pancreatic duct

• contains carbohydrases (pancreatic amylase), proteases (trypsin) and lipases

bile

• PHYSICAL DIGESTION

• produced by liver

• temporarily stored in gallbladder

• enters duodenum via bile duct

• contains bile pigments and bile salts

• does not contain enzymes

• greenish-yellow pigment

emulsification of fats

• begins in and completed in the small intestine

• bile salts emulsify fats - they break down the fats into small fat droplets that are suspended in water