Diet, Disease, and Digestion

1. Diet, Disease, and Digestion Eva Murdoch, PhD Assistant Professor, Anatomy and Physiology Department of Natural Sciences Joliet Junior College

2. Organs of the Digestive System • Gastrointestinal tract (GI): mouth, esophagus, stomach, small & large intestine • Accessory organs:salivary glands, liver, gall bladder, pancreas

3. Functions of the GI tract and Accessory Organs • GI tract: continuous muscular tube which passes, digests, and absorbs food molecules, and eliminates the indigestible residue • Accessory organs: release digestive juices into the muscular tubule, and aid in the breakdown of nutrients

4. Digestive System • Living organisms must obtain nutrients from their environment to sustain life • The digestive system breaks down large nutrient molecules to small nutrient molecules that all body cells can then use to: • Synthesize ATP (cell’s energy supply) • Perform structural maintenance, repair and support growth

5. Digesting and Absorbing Nutrients • Salivary glands, pancreas and liverhelp with the digestion of large food molecules to small molecules by secreting enzymes • DigestionAbsorption • Carbsmonosacchrides blood • Fatsfatty acids blood • Proteinsamino acids blood

6. Cell Metabolism • All chemical reactions that occur in a cell • Synthesis of ATP • Synthesis of new organic molecules, and other cell functions that require ATP

7. Nutrient Molecules • Function: short-term energy supply 4 Cal / 1 gram (calories are a unit of energy) • Found in: grains (wheat, rice, oats, corn), fruits, veggies • Carbohydrates / Sugars

8. Lipids / Fats • Function: energy reserve, padding, insulation 9 Cal / 1 gram • Found in: nuts, red meat, milk, eggs, butter

9. Proteins • Functions: enzymes, hormones, muscle, last resort for energy 4 Cal / 1 gram • Found in: meat, nuts, beans, dairy, eggs

10. Diet Pyramid

12. Disease • GERD – gastro-esophageal (acid) reflux disease • Cause: stomach acid in the esophagus, due to weak esophageal sphincter • Pathology: erosion of esophageal tissue  pain • Treatment: largely preventable by changes in lifestyle, medication, surgery

13. Stomach ulcer • Cause: inflammation due to H. pylori infection • Pathology: bleeding instomach • Treatment: antiacid, antibiotics, anti-inflammatories • Stomach cancer • Cause: H. pylori infection, genetics • Pathology: abnormal growth (tumor) in stomach tissue • Treatment: surgery, chemotherapy

14. Colon polyp • Cause: irritable bowl syndrome (IBS) history • Pathology: abnormal growth, rectal bleeding • Treatment: surgery

15. Colon Cancer (3rd most commonly diagnosed cancer) • Cause: genetic, polyps, diet, smoking, excessive drinking • Pathology: uncontrolled cell growth in colon, rectal bleeding • Treatment:surgery, chemotherapy, radiation therapy

16. Liver cirrhosis • Cause: chronic alcoholism and hepatitis C infection • Pathology: liver cells (hepatocytes) are replaced by fibroblasts (cells found in tendons, can’t perform liver functions) • Treatment: liver transplant

17. Pancreatic Cancer • Cause: genetics, age, smoking, diet, diabetes • Pathology: mutations in the pancreatic cell and tumor growth • Treatment: surgery, chemotherapy