What is the major site for digestion and absorption of nutrients?
The small intestine
What enzymes are involved in lumen digestion?
pancreatic amylase, pancreatic proteases, pancreatic lipase and bile acids
What enzymes are involved in surface digestion?
brush border disaccharidases and brush border peptidases
What are the major cell types found in the small intestine?
(1) Columnar absorptive cells- surface digestion and nutrient transporters (2) Mucous (goblet) cells (3) Intraepithelial lymphocytes (4) Enterochromaffin (endocrine) cells (5) undifferentiated cells- give rise to the other types
What is the primary function at the tip of villi?
What is the primary function at the crypt of villi?
What three forms are carbohydrates acquired in the diet as?
glucose, fructose, galactose
What is lactose broken down into?
glucose and galactose by lactase
What is sucrose broken down into?
glucose and fructose by sucrase
What forms do polysaccharides come in in the diet?
starch, glycogen, and fiber
Transport of monosaccharides is coupled with?
absorption of sodium and water
How is protein broken down?
(1) Intraluminal digestion via a large number of proteolytic enzymes secreted by the pancreas that break down proteins into small peptides and amino acids (2) surface digestion by a large number of brush border peptidases that generate single amino acids and dipeptides