Digestive System health.howstuffworks/adam-200142.htm

1. Digestive Systemhttp://health.howstuffworks.com/adam-200142.htm Swenson

3. Salivary Glands • Secrete enzyme amylase (breaks down carbs) • cover food to produce bolus (Mucous lubricates food)

4. Tongue • moves food side to side to be chewed and keeps between teeth • moves bolus to back of throat • closes off mouth when swallowing

5. Trachea • Wind Pipe • Epiglottis – flap of skin that covers the trachea so food does not enter the wind pipe and cause you to choke.

6. Esophagus a. Food to the stomach by peristalsis

7. Liver • produces and secretes bile which emulsifies fats • detoxifies blood • stores glycogen (animal form of starch) • Reduces/neutralizes acidse. bile breaks up fats

8. Gall Bladder a. Stores bile

9. Stomach • churn/mix food • digestion of proteins starts here • Gastric juice is acidic (HCl) and contains pepsin (enzyme to digest proteins) • Gastrin (hormone) stimulates to release of gastric juice • vomiting-reverse peristalsis • pyloric sphincter controls opening and end of stomach

10. Bile Duct a. duct or tube from gall bladder to small intestine

11. Trachea • wind pipe • protected by epiglottis during swallowing (covering)

12. Small Intestine • 20 – 30 feet long • parts of sm. Intestine are: • duodenum – listed above • jejunum – has folds of skin called the brush border membrane. • ileum – selective absorption of some nutrients. What remains is liquid stool • Final digestion occurs here • food is absorbed in simplest forms – amino acids, fatty acids, glycerole. • Villi – small finger like projects that contain vessels to absorb food

13. Duodenum a. Most of the digestion begins here (proteins, fats and carbs)

14. Pancreas • produces powerful digestive enzymes • Produces and secretes insulin – important in regulating blood sugar levels Pancreas Duct a. A duct or tube from pancreas to small intestine

15. Appendix • Vestigial organ – “dead end” a. May at one time have aided in digestion of cellulose but has no function today

16. Large Intestine (colon) • Parts are: Cecum – large entrance controlled by a sphincter that protects the small intestine from the large intestines concentrated bacteria, • Ascending colon – upwards, • Transverse colon – across, • descending colon – down, • sigmoid colon – end f. reabsorbs water g. Some solid wastes are stored before they enter rectum

17. Rectum • Rectum a. Stores solid waste until full • Anus a. Controlled by sphincter muscle by peristalsis.

18. Digestion animation review • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter26/animation__organs_of_digestion.html

19. Digestive Processes I. Ingestion • Takes food in – mouth II. Peristalsis a. Muscular contractions along digestive tract-esophagus  small and large intestine

20. Absorption • Taking of digested food into blood stream • Occurs in Sm. Intestine • Storage • Animal “starch” stored as glycogen in liver • Elimination • Solid waste eliminated from large intestine

21. Mechanical Digestion • Physically chewing-mouth • Churning action-stomach • Chemical Digestion • Uses enzymes • Starts carbohydrate breakdown in mouth • Starts protein breakdown in stomach • Carbohydrates, proteins, and fats are fully digested in Sm. Intestine

22. Types of Food Food Type % Diet Purpose Digestive End Product Fats <30% Store energy Glycerol + 3 Absorb Vitamins fatty acids Protect organs Carbohydrates55% Energy source monosaccharides Absorption of food glucose Fiber Proteins >15% Growth Amino Acids maintenance/repair makes enzymes

23. What happens to the Digestive End Product (listed above):  Absorbed into blood and delivered to cells and organs • For Fats  used or stored • For Carbohydrates used for energy or stored • For Proteins used to rebuild/enzymes • Remember organisms are very efficiently adapted to providing the nutrients they need. The complex process of changing one type of macromolecule into another is very complex with any one able to change into the other, through many steps and much energy input.

24. To speed Digestion organisms use chemicals and enzymes • Acids • Gastric acid in stomach • Contains HCl • Bile • Secreted by liver-stored in gall bladder • Emulsifies fats (dissolves-NOT digest) • Enzymes – each enzyme (made of protein) is regulated, with a special “job” • Jobs include • Operate by “Lock and Key” approach • Some examples • Hydrolysis – (Breaking down polysaccharides to create simple sugars)

25. Enzymes are: 1. Highly specific 2. Can speed up the same chemical reaction in either direction. 3. NOT used up in the reaction.

26. Lipase is an enzyme that digests fat. Bile is a solution that emulsifies fats. Together, they speed up the breakdown of fats in the digestive system.

27. Enzymes in Plants • Remember, Autotrophs make their own organic nutrients (simple sugars). How do plants do this? • Enzymes speed the necessary chemical reactions and give organisms the ability to control how much, where, and when these reactions occur Glucose is coupled together into starch in the roots of plants for storage. • The enzyme for this reaction is called: Sucrase • The chemical reaction that occurs is a Dehydration Synthesis, draw the structures of two glucose molecules being joined to create a disaccharide.

28. How do they work? • Enzymes function by binding to one or more of the reactants (substrate) in a reaction. • The exact location on the enzyme where substrate binding takes place is called the active site of the enzyme. • The shape of the active site just fits the shape of the substrate, somewhat like a lock fits a key. • In this way only the correct substrate binds to the enzyme

29. http://www.efhealing.com/images/enzymes.jpg

30. Types of Enzymes Enzyme Made Here Acts Purpose Amylase Mouth & Mouth & breaks polysacs to Pancreas Sm. Intestine disacs (digests carbs) Pepsin Gastric glands Stomach Starts digestion of stomach Rennin Stomach Stomach Coagulates (thickens) protein in milk Lipase Pancreas Sm. Intestine Reduces fats to fatty acids and glycerol (building blocks of fats)

31. Enzymatic Digestion of food types (Macromolecules) Name the chemical process used by these enzymes to help digest fats, carbohydrates, and proteins: • Use diagrams of Macromolecules to fill in the chart below. Use circled numbers to indicate locations of hydrolysis • http://www.whfoods.com/genpage.php?tname=faq&dbid=16#digestion Hydrolysis

32. Digestive Problems: • Lactose Intolerence - Inability to digest milk sugar (enzyme lactase) Appendicitis - Bacteria gets in appendix and causes flu like symptoms and eventually shooting pain in right side. Surgically removed.

33. Tape worms Parasite that stays in your intestines and absorbs all the nutrients. Get it from undercooked meat. Diabetes Cannot produce insulin in pancreas