1. Objectives To list the secretions involved with the digestive system. To identify some of the disorders of the digestive system. Review for the exam. - Focus on electrolytes Remember Case Study Due next period! Pg 25 & 26

2. Carbohydrates A compound composed of C, H and O With the approximate chemical formula (CH 2 O) n Example C 6 H 12 O 6 – glucose Digested by Amylase (an enzyme produced by the salivary glands and pancreatic secretions). Important for starch digestion. Leftover cellulose is further metabolized by bacteria with necessary enzymes  Vitamins K & B12 are byproducts.

3. Proteins Polymers of amino acids joined by peptide bonds. Important in structure and function of all living organisms – found in muscles. Generally obtained in the diet by eating animal products. Digested by: Stomach: HCl, Pepsin, Pancreas: Peptidases, Trypsin, Chymotrypsin

4. Lipids Organic, hydrophobic molecules that are insoluble in water. Contain fatty acid subunits and a carboxyl group (– COOH). Includes: Triglycerides – fats and oils. Phospholipids – found in cell membranes. Cholesterol – important for steroid hormones.

5. Digestion of Lipids Liver/Gall Bladder – Bile (emulsifies) Pancreas – Lipase (an ENZYME) > Breaks down lipids into their components  fatty acids &glycerol.

6. Hormones involved with Digestion Stomach – Gastrin: stimulates acid secretion by cells in the stomach and distension of stomach. Small Intestine - Secretin: stimulates HCO3 production by pancreas and liver to neutralize acid, increases bile output. Cholecystokinin: stimulates secretion of pancreatic enzymes and bile by gallbladder. CCK Gastric inhibitory peptide: inhibits stomach acid.

7. Recap – What is where? Stomach HCl Mucus Pepsin Pepsinogen Gastrin – H secreted here Small Intestine Sodium bicarbonate Amylase Peptidase Trypsin Chymotrypsin Lipase Bile Peptidase Secretin – H Cholecystokinin – H Gastric Inhibitory Peptide - H

8. Processes: Mastication - Chewing Deglutition – Act of swallowing Peristalsis – Wave movement through tube. Absorption – Incorporation into blood/cells. Elimination – Removal of wastes

9. Diseases and Disorders Ulcers – caused by Helicobacter pylori. Appendicitis – inflamed appendix. Enteritis – inflammation of the intestine (sm). Irritable Bowel Syndrome –alt of diarrhea & constipation Colon Cancer – often due to carcinogens. Gallstones – Precipitate of bile salts > blockage. Jaundice – accumulation of bile salts in the blood.

10. Review of Electrolyte Imbalances Hyperkalemia Elevated K+ Can occur due to acidosis Symptoms: Muscle weakness Nausea Cardiac arrhythmia Intestinal colic Hypokalemia Deficiency of K+ Can occur due to alkalosis, gastric suctioning, vomiting, diarrhea Symptoms: Fatigue Muscle weakness Anorexia Cardiac arrest

11. Review of Electrolyte Imbalances Hypercalcemia Elevated Ca+ Can occur due to acidosis, Or overactive parathyroid. Symptoms: Poor coordination Poor appetite Constipation Hypocalcemia Deficient Ca+ Can occur due inactive parathyroid, low dietary calcium intake. Symptoms: Tingling in extremities Increased neuron excitability Tetany Carpopedal spasms Convulsions and seizures.