1 / 22

The Digestive System

The Digestive System. An Adventurous Journey Through the Darkest Twists and Turns of our Bodies. Objectives. By the end of this unit you will be able to: Identify the functions of the Digestive System Identify and describe the role of the different organs of the Digestive System

eadoin
Download Presentation

The Digestive System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Digestive System An Adventurous Journey Through the Darkest Twists and Turns of our Bodies

  2. Objectives By the end of this unit you will be able to: Identify the functions of the Digestive System Identify and describe the role of the different organs of the Digestive System Analyze characteristics and treatment of common digestive disorders

  3. Functions of Digestive System Mechanical breakdown of food. Chemical digestion of food into the end products of fat, carbohydrates, and protein. Absorption of nutrients. Elimination of waste products after digestion.

  4. Digestion

  5. Alimentary Canal Also called gastrointestinal tract (GI) 30 ft long tube from mouth to anus Includes : oral cavity, pharynx, esophagus, stomach, small intestine, large intestine Accessory Organs – liver, pancreas, gallbladder, Salivary glands

  6. Oral Cavity Digestion begins in the mouth (both chemical and mechanical): • Teeth tear and grind food into smaller pieces – mastication • Salivary glands secrete saliva – moistens and helps break down food • Tongue – moves food around mouth, helps in chewing and swallowing, taste buds (papilla) help brain decipher what it is eating

  7. Salivary glands 3 pairs (ones that swell up when sick are called Parotid Glands….just FYI) Produce saliva which helps liquefy food, making it easier to digest 99% water but also has enzymes – ptyalin – begins the breakdown of starch (chemical digestion) Bolus – wet, nondescript and utterly repugnant mass of matter that used to be food

  8. Pharynx Receives food from your mouth Act of swallowing occurs in pharynx Keeps food from going into trachea (air passageway)Epiglotiss – flap of skin that keeps food from trachea Bolus is pushed from pharynx to esophagus through process of peristalsis.

  9. Epiglottis

  10. Esophagus 9-10 inch long flexible tube-like structure Passes food from Pharynx to stomach Moves food down through process of peristalsis.

  11. Stomach Sac-like structure located in upper left quadrant of abdomen Filled with gastric juices and mucus Helps further breakdown food Gastric juice composed mainly of Pepsin – enzyme that breaks down proteins Hydrochloric acid destroys unwanted bacteria and microorganisms

  12. Stomach (cont…) Around 35 million gastric glands produce gastric juice Mere sight or smell of food is enough to make your glands in your stomach secrete more gastric juices Cardiac sphincter – ring like structure located between esophagus and stomach, keeps food in stomach Pyloric sphincter – separates stomach and small intestine Food turns to chyme in stomach Chyme – semiliquid, creamy, homogeneous, substance that used to be food

  13. Stomach

  14. Stomach Answer: The stomach secretes and maintains a mucous lining which acts as a protective barrier. Why doesn’t the hydrochloric acid eat away the stomach?

  15. Small Intestine 1 inch diameter by 23 feet long Where most absorption occurs Food is now broken down into usable substances which can be used by tissues Absorbed by villi – line walls of small intestine Nutrients are either sent to blood or put into storage Water also absorbed

  16. Small Intestines As much as 10 Liters! How much water, on average, do you think the small intestines absorb on a daily basis?

  17. Small Intestine x 10 OR

  18. Liver • 3-4 pound organ located in upper right quadrant of abdomen • Largest in body • Many jobs: • Maintains correct blood sugar levels • Filters out and destroys old red blood cells • Produces bile • Stores vitamins such as K, A, D, E, B12 • Produces prothrombin – vital for blood clotting • Filters out harmful toxins that may be swallowed

  19. Gallbladder Stores bile – breaks down fat like soap breaks down grease Can store about 50 milliliters of bile 7-10 cm long You can live without your gallbladder but with dietary restrictions and bile supplements

  20. Pancreas Located behind stomach Oblong, flatten organ about 15 cm long Produces pancreatic juice, contains enzymes Helps digest proteins and fat Also helps control insulin production You can live without pancreas but very difficult

  21. Large Intestine About 5 ft long and 2 inches diameter Some nutrients absorbed here that weren’t in small intestine Water and salts absorbed storage and elimination structure for indigestible substances Food still in chyme form when it enters but colon (last section of large intestine) converts chyme to feces Food passes more slowly – less water Defecation – elimination of waste (feces)

  22. Digestive System

More Related