Recrete intrinsic factor used for the absorption of vitamin B12Receptors can be blocked by Tagamet, Zantac; proton pumps(hydrogen/potassium ATPase pumps) can be inhibited by Prevacid, Prilosec,Acifex);
secrete the zymogen pepsinogen which is converted into pepsin (a protease) by acid and autoactivation
impairs ability of stomach and intestine to defend itself from HCl; important factor in peptic ulcer formation.
duodenum, jejunum, ilium complete digestive process and absorb nutrients.
Receives bile from liver/gall bladder and digestive juice from ascinar cells of pancreas
release hormones secretin (stimulates release of bicarbonate from Brunner's glands and duct cells of pancreas to neutralize stomach acid), CCK (cholecystikinin; stimulates release of bile from gall bladder, relaxes sphincter of Oddi, stimulates release of digestive enzymes from pancreatic ascinar cells, stimulates satiety center of brain), and GIP (gastric inhibitory peptide or glucose-dependent insulinotropic peptide; inhibits motility of stomach and stomach emptying into duodenum and stimulates release of insulin from beta cells of islets of Langerhans of pancreas)
a brush border enzyme that activates trypsinogen into trypsin which in turn activates chymotrypsinogen, proelastase, procarboxypeptidase from pancreas.
secrete bicarbonate rich mucus to protect first part of duodenum.
Villi & microvilli
Increase surface area of intestine for better absorption, brush border enzymes
Jejunum & Ilium
Complete digestion of foods and absorb nutrients into bloodstream (capillaries in villi) or into lacteals (for larger fatty molecules)
Crypts of Lieberkuhn
(intestinal glands) secrete digestive enzymes into intestinal lumen
absorption of water, production of B vitamins and vit K by bacteria, preparation of mucus rich feces for elimination from body; tubular glands produce mucus
Produces bile with bile pigments (from breakdown of hemoglobin; bilirubin, biliverdin) and bile salts (cholic acid and chenodeoxycholic acid are both produced from cholesterol with carboxyl group; act as detergents to emulsify fats so that lipases in small intestine is able to digest those fats; recycled back into bloodstream by carrier molecules in the ileum)
stores bile, concentrates bile by absorption of water; contracts and secretes bile into the duodenum in response to CCK hormone released from enteroendocrine cells of the duodenum.
hepatic ducts, cystic duct and common bile duct
Ascinar cells secrete digestive enzymes (lipases, amylases, nucleases, protease zymogens (trypsinogen, chymotrypsinogen, proelastase, procarboxypeptidase)) into duodenum through the pancreatic duct and ampulla of Vater in response to CCK hormone.
Islet of Langerhans secrete hormones (alpha cells secrete glucagon during periods of hypoglycemia; beta cells secrete insulin during periods of hyperglycemia
Duct cells release bicarbonate into duodenum in response to secretin hormone stimulation.
renal tubule (Bowman's capsule, PCT, loop of Henle, DCT, and collecting duct) and associated blood vessels (afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries, vasa recta)