THE DIGESTIVE (GI) SYSTEM

THE DIGESTIVE SYSTEM IS ALSO KNOWN AS THE “GI— GASTROINTESTINAL SYSTEM” IT IS RESPONSIBLE FOR THE PHYSICAL AND CHEMICAL BREAKDOWN OF FOOD SO THAT ITS NUTRITIONAL BENEFITS CAN BE ABSORBED INTO THE BLOOD STREAM AND DISTRIBUTED TO THE BODY’S CELLS/TISSUES/ORGANS. CAREERS: GASTROENTEROLOGIST, REGISTERED DIETICIAN/NUTRITIONIST, SURGEON, DENTAL CAREERS, ENTEROSTOMAL RN, DIABETES EDUCATOR, HEPATOLOGIST, INTERNIST, PROCTOLOGIST SO WHERE DOES DIGESTION BEGIN????????

IN THE MOUTH—THE BUCCAL CAVITY

THE ALIMENTARY CANAL—LONG MUSCULAR TUBE THAT BEGINS AT THE MOUTH AND ENDS WITH THE ANUS

THE STOMACH RECEIVES FOOD FROM ESOPHAGUS LINING CONTAINS FOLDS CALLED RUGAE WHICH DISAPPEAR AS IT EXPANDS HAS TWO SPHINCTERS: CARDIAC: BETWEEN ESOPHAGUS AND STOMACH, CLOSES TO PREVENT FOOD FROM BACKING UP INTO ESOPHAGUS PYLORIC: BETWEEN STOMACH AND SMALL INTESTINE, KEEPS FOOD IN STOMACH TILL READY TO GO TO S.I. FOOD REMAINS IN STOMACH ABOUT 2-4 HOURS FOOD CONVERTED TO “CHYME” A SEMIFLUID MATERIAL, BY GASTRIC JUICES AND HYDROCHLORIC ACID. CHYME GOES ON TO THE SMALL INTESTINE

SMALL INTESTINE

LARGE INTESTINE

SMALL INTESTINE CHYME ENTERS THE S.I. THE PROCESS OF DIGESTION IS COMPLETED HERE PRODUCTS ABSORBED BY THE VILLI BLOOD CAPILLARIES AND TRANSPORTED TO BLOODSTREAM THEN TO CELLS, TISSUES, ORGANS MALTASE, SUCROSE, LACTASE BREAK DOWN SUGARS BILE BREAKS DOWN FATS OTHER ENZYMES ARE AT WORK TOO! LARGE INTESTINE ABSORPTION OF H20 AND REST OF NUTRIENTS STORAGE OF INDIGESTIBLE MATERIALS SYNTHESIS OF VITAMINS B AND K— REMEMBER PERNICIOUS ANEMIA? TRANSPORTS WASTED OUT OF THE ALIMENTARY CANAL

LIVER LARGEST GLAND IN THE BODY SECRETES BILE TO EMULSIFY FATS, MAKES THEM WATER SOLUBLE STORES SUGAR AS GLYCOGEN AND BREAKS IT DOWN TO GLUCOSE WHEN NEEDED FOR ENERGY PRODUCES HEPARIN AND OTHER CLOTTING AGENTS, CHOLESTEROL DETOXIFIES SUBSTANCES SUCH AS ALCOHOL AND PESTICIDES AND DESTROYS BACTERIA THAT HAVE BEEN TAKEN INTO THE BLOODSTREAM FROM INTESTINE

GALLBLADDER SMALL MUSCULAR SAC LOCATED UNDER LIVER STORES AND CONCENTRATE BILE, RECEIVED FROM THE LIVER BILE USED TO EMULSIFY FATS PUSHES BILE INTO DUODENUM

PANCREAS GLANDULAR ORGAN LOCATED BEHIND STOMACH PRODUCES PANCREATIC JUICES THAT CONTAIN ENZYMES TO DIGEST FOOD ENTER THROUGH THE DUODENUM VIA THE PANCREATIC DUCT PRODUCES INSULIN SECRETED INTO THE BLOODSTREAM INSULIN REGULATES METABOLISM OF CARBS TO CONVERT GLUCOSE TO ENERGY