Opening Activity

1. Opening Activity Directions: After you eat the snack provided, write the following parts of the digestive system in the order your snack passes through your body. Do not include accessory organs within your list. Not every part will be used. THE WINNING GROUP GETS 5 EXTRA CREDIT POINTS ON THEIR QUIZ

2. Duodenum • Pharynx • Stomach • Jejunum • Mouth • Colon • Esophagus • Anus • Salivary glands • Ilium • Pancreas

3. The Digestive System By: Rebecca DePalma, Elisha Son, & Connor Kuykendall

4. Function Turning food into the energy you need to survive and packaging the residue for waste disposal

5. Organs of the Digestive System Location and Function

6. Salivary Glands Mouth Pharyx Esophagus Liver Stomach Gallbladder Pancreas Small intestine Large intestine Rectum Anus

7. Function: Mouth Mechanical breakdown of food, chemical digestion of carbs

8. Function: Pharynx Connects mouth to esophagus

9. Function: Esophagus Peristalsis pushes food to stomach

10. Function: Stomach Mixes food with secretions to begin protein digestion

11. Function: Small Intestine Mixes food with pancreatic juice and bile, breakdown of food molecules

12. Small Intestine Breakdown Duodenum - fixed portion of the small intestine, first portion following the stomach; 25 cm long Jejunum - next portion, making up 2/5 of the small intestine Ileum - the remainder of the small intestine Mesentery - double-layered fold of peritoneal membrane; suspends intestines from the posterior abdominal wall Intestinal villi- tinyprojections of mucous membrane, greatly increasing the surface area of the lining, aiding absorption; numerous in the duodenum

13. Function: Large Intestine AKA Colon; Absorbs water and electrolytes to form feces (indigestible materials in preparation for elimination)

14. Function: Rectum to Anus Regulates elimination of feces

15. Accessory OrgansFunction: Salivary Glands Secretes saliva

16. Accessory OrgansFunction: Liver Produces bile which emulsifies fat

17. Accessory OrgansFunction: Gallbladder Stores bile and introduces it into the small intestine

18. Accessory OrgansFunction: Pancreas Produces/secretes pancreatic juice into small intestine

19. Structure of Alimentary Canal • Consists of 4 distinct layers; mucosa, submucosa, muscular layer, and serosa • Mucosa: • Formed by surface epithelium, underlying connective tissue, and a small amount of smooth muscle • In certain regions, the mucosa is folded with tiny projections that extend into the passageway (lumen) • Lumen increases absorptive surface area • Mucosa protects the tissues underneath it and carries on secretion and absorption • Has glands that are tubular invaginations into which the lining of the cells secrete mucus and digestive enzymes

20. 2. Submucosa • Consists of loose connective tissue, glands, blood vessels, lymphatic vessels, and plexus • Plexus – nerves organized into a network • Its vessels nourish surrounding tissues and carry away absorbed materials

21. 3. Muscular Layer • Produces movement of the tube • Consists of 2 layers of smooth muscle tissue + some nerves organized into a plexus • Circular fibers – fibers of the inner layer that encircle the tube • Contraction of circular fibers result in a decrease in diameter of the tube • Fiber of the outer muscular coat run lengthwise • When these longitudinal fibers contract, the tube shortens

22. 4. Serosa • AKA serous layer • Visceral peritoneum has a serous layer, or outer covering, of the tube • The cells of the serosa protect underlying tissues • Also secretes serous fluid which moistens and lubricates the tube’s outer surface so that organs within the abdominal cavity slide freely against one another

23. Movements of the Tube • Two motor functions: • 1. Mixing movements • occurs when smooth muscles in small segments of the tube contract rhythmically • ex: muscular contractions to mix food with digestive juices • 2. Propelling movements • includes peristalsis (wavelike motion) • ring of contraction appears in the wall of the tube • pushes tubular contents ahead of it (think of it as a propeller)

24. Digestive Enzymes • Digestion enzymes are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body • Aid in the digestion of food

25. Digestive Enzymes cont. Where are they found? • Stomach secreted by cells lining the stomach • Pancreatic juice secreted by pancreatic exocrine cells • Saliva secreted by the salivary glands • Small and large intestinal secretions

26. Products of Digestion: Absorption Locations Water: • Large Intestine - absorbs water and electrolytes • Vitamins & Minerals • Small intestine - absorbs these, organic substrates, and ions Food: • Stomach - enzymatic digestion of proteins • Small Intestine - main site of nutrient absorption

27. Absorption Mechanisms • Water: -Osmosis • Electrolytes: -Diffusion, active transport • Monosaccharides: -Facilitated diffusion, active transport • Fatty acids and glycerol: -Facilitated diffusion • Amino acids: -Active Transport

28. Carbohydrate Digestion To Cells • Breaks down glycogen to glucose • Converts non-carbohydrates to glucose • Polymerizes glucose to glycogen

29. Protein Digestion To Cells • Deaminates amino acids • Forms urea • Synthesizes plasma proteins • Converts certain amino acids to other amino acids

30. Lipid Digestion To Cells • Oxidizes fatty acids • Synthesizes lipoproteins, phospholipids, and cholesterol • Converts portions of carbohydrate and protein molecules into fats

31. Diseases of the System: • Hiatal hernia: • portion of the stomach protrudes through a weakened area of the diaphragm • results: gastric juices regurgitate into the esophagus, causing heartburn, difficulty in swallowing, or ulceration, and blood loss • Ulcers: • open sore in the skin or mucous membrane resulting from localized tissue breakdown • caused by the bacteria, helicobacter pylori • cures: acid reducing drugs and antibiotics • Tonsillitis: • infected tonsils tend to swell • may swell to the point where they block the passageways of the pharynx and interfere with breathing and swallowing • may have to get them removed if patient is non responsive to antibiotics

32. Diseases of the System: • Jaundice: • turns the skin and whites of the eyes yellow • reflects buildup of bile pigments • obstructive jaundice: bile ducts are blocked • hepatocellular jaundice: liver is diseased • hemolytic jaundice – red blood cells are destroyed too rapidly • Cystic fibrosis: • abnormal chloride channels in cells in various tissues draw water inward from interstitial spaces • dies out secretions in the lungs and pancreas, leaving a sticky mucus behind • Acute pancreatis: • extremely painful condition • results from a blockage in the release of pancreatic juices • Alcoholism, gallstones, certain infections, traumatic injuries, or the side effects of some drugs can cause pancreatis

33. Nutrition • Adequate diets provide sufficient energy, essential fatty acids, amino acids, vitamins, and minerals • Food pyramid: carbs, fruits, vegetables, protein, dairy, fats/oils/sweets

34. Nutrition • Individual requirements vary based on age, sex, growth rate, levels of stress, etc... • Malnutrition – lacking essential nutrients • Ex: anorexia, bulimia • Normally active people (3x per week) would need more calories than a person who doesn’t exercise at all • Your body needs to replace burned calories by obtaining more nutrients and carbs