Digestive System


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Digestive System

  1. 1. Digestive System
  2. 2. Vocabulary <ul><li>__________ - life function by which humans use for energy, growth, and repair </li></ul><ul><li>___________- mouth </li></ul><ul><li>___________- wave of muscular contractions </li></ul><ul><li>__________- microscopic parts that help with absorption in the small intestine </li></ul><ul><li>____________- bile movements (semi solid stored in rectum) </li></ul><ul><li>_____________ - splitting by adding water (break down od big pieces into smaller ones) </li></ul>Nutrition Oral Cavity villi Peristalsis feces Hydrolysis
  3. 3. Let’s Review <ul><li>One of the Life Process that are similar in ALL Living things is nutrition. </li></ul><ul><ul><li>Nutrition is needed for growth, repair, and energy. </li></ul></ul><ul><ul><li>In order for us to us nutrition we need to break down the nutrients into small enough pieces that they can reach each cell. </li></ul></ul><ul><ul><li>Our bodies need a healthy diet this includes the right amount of protein, carbs, fats, and minerals </li></ul></ul>
  4. 4. So how do we get these nutrients in our bodies? I Don’t know!!! Let me sleep! OOOOHHHH. I know…. Digestive System
  5. 5. Digestive System Overview <ul><li>There are four parts to digestion </li></ul><ul><li>__________- taking in food </li></ul><ul><li>___________- mechanical and chemical breakdown of food so that it can be absorbed by the cells </li></ul><ul><li>______________ : cells lining the digestive tract take up (absorb) small nutrient molecules </li></ul><ul><li>________________ : undigested material passes out of the digestive tract </li></ul>Ingestion Digestion Absorption Elimination
  6. 6. There are two ways digestion breaks up the food <ul><li>1. Mechanical digestion – physical breakdown of large pieces of food into smaller ones </li></ul><ul><li>2. Chemical digestion – hydrolysis – the splitting of large molecules into small, molecules with the use of water and enzymes ( in other words; breaking complex molecules into simple ones) </li></ul><ul><li>The process of chemical digestion ( hydrolysis ) is controlled by enzymes </li></ul>
  7. 7. Examples of Chemical Digestion : <ul><li>1. Carbohydrates+ water -> simple sugars (glucose for instance) </li></ul><ul><li>2. Proteins+ water -> amino acids </li></ul><ul><li>3. Lipids+ water -> 3 fatty acids +gylcerol </li></ul>
  8. 8. How Does Our Digestive system work?
  9. 9. HUMAN DIGESTIVE SYSTEM <ul><li>The digestive system is a one way food tube that goes from the Oral Cavity to the rectum. </li></ul><ul><li>This one way track is called the GI track ( gastrointestinal ) </li></ul>
  10. 10. Oral Cavity <ul><li>Oral Cavity is a fancy name for a mouth </li></ul><ul><ul><li>Used to ingest (take in food) </li></ul></ul><ul><li>Teeth - function in mechanical breakdown of food, increases surface area of food for enzyme action </li></ul><ul><li>Tongue - </li></ul>
  11. 11. Teeth &Tongue <ul><li>Teeth - function in mechanical breakdown of food, increases surface area of food for enzyme action </li></ul><ul><li>Tongue acts as a plunger to push food back into the throat ( pharynx ) taste buds are located on the surface of the tongue </li></ul><ul><li>The enzyme reaction is caused by saliva </li></ul><ul><ul><ul><li>Saliva is secreted (let out) by the salivary glands </li></ul></ul></ul><ul><ul><ul><li>The saliva’s job is to begin the Chemical digestion of carbohydrates etc.. </li></ul></ul></ul>
  12. 12. Pharynx <ul><li>Pharynx is another name for the throat </li></ul><ul><ul><li>The tongue pushes the food to the back of the throat </li></ul></ul><ul><ul><ul><li>This starts the swallowing </li></ul></ul></ul><ul><ul><ul><li>food is now in the form of a bolus </li></ul></ul></ul><ul><ul><li>Epiglottis : flap that prevents choking </li></ul></ul>
  13. 13. Esophagus <ul><li>Esophagus : muscular tube that moves food from mouth to the stomach by process of peristalsis : wave of muscular contractions that moves chewed food to stomach </li></ul>
  14. 14. Stomach <ul><li>Stomach : J-shaped, sac-like , muscular organ </li></ul><ul><li>mechanically churns food into a liquid and begins chemical digestion </li></ul><ul><li>lining secretes gastric juice, </li></ul><ul><li>stomach empties in about 2-6hrs., </li></ul><ul><li>food now liquid called chyme </li></ul>
  15. 15. Gastric Juice <ul><li>Components of gastric juice: </li></ul><ul><ul><li>1. water-solvent </li></ul></ul><ul><ul><li>2. mucus-lubrication </li></ul></ul><ul><ul><li>3 . enzyme that begins chemical digestion of protein </li></ul></ul><ul><ul><li>4. hydrochloric acid (HCl) </li></ul></ul>
  16. 16. Small Intestine <ul><li>the major organ of chemical digestion and nutrient absorption, </li></ul><ul><li>long twisted tube with small diameter, </li></ul><ul><li>enzymes and fluids needed to complete chemical digestion come 3 separate sources: </li></ul><ul><ul><li>1. intestine itself </li></ul></ul><ul><ul><li>2. pancreas-. Small intestine </li></ul></ul><ul><ul><li>3. liver-> gallbladder->small intestine </li></ul></ul><ul><li>Main organ for absorption </li></ul><ul><li>Villi : fingerlike projections that increase surface area of small intestine contain a network of capillaries for absorption of amino acids and simple sugars into blood, center contains lymph vessel called lacteal which absorbs fatty acids </li></ul>
  17. 17. Large Intestine <ul><li>The food now goes into the large intestine </li></ul><ul><ul><li>It gets the food that has not been digested </li></ul></ul><ul><ul><li>Usually in a liquid state </li></ul></ul><ul><ul><li>NO digestion occurs here </li></ul></ul><ul><ul><li>Reabsorbs the water and solidifies the waste – known as feces </li></ul></ul><ul><ul><ul><li>the feces are stored at the lower end of the Long Intestine called the rectum </li></ul></ul></ul><ul><ul><ul><ul><li>Leaves the body through the anus </li></ul></ul></ul></ul>
  18. 18. Accessory Organs to the digestive system <ul><li>Even though not part of the food tube there are important organs for digestion </li></ul><ul><li>This includes </li></ul><ul><ul><li>Liver </li></ul></ul><ul><ul><li>Gallbladder </li></ul></ul><ul><ul><li>Pancreas </li></ul></ul>
  19. 19. Liver <ul><li>largest internal organ ( has many functions outside digestion) </li></ul><ul><ul><li>Makes bile ~ bile NOT an enzyme,) </li></ul></ul><ul><ul><ul><li>Bile breaks down lipids- breaks them into smaller droplets to increase the surface area for enzymes (lipases) to act on fats </li></ul></ul></ul>
  20. 20. Gallbladder <ul><li>small storage sac for bile, carries bile to small intestine </li></ul>
  21. 21. Pancreas <ul><li>Pancreas : located near small intestine </li></ul><ul><ul><li>Produces juices, enzymes, and fluids </li></ul></ul><ul><ul><ul><li>These enzymes are important to break down complex molecules into soluble end products </li></ul></ul></ul><ul><ul><ul><ul><li>Such as </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Glucose </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Amino acids </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Fatty acids </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Glycerol </li></ul></ul></ul></ul></ul>
  22. 22. Digestive Homeostasis Disorders <ul><li>1.Constipation – person has uncomfortable or infrequent bowel movements results from sluggish peristalsis that allows excess water to be removed from feces (fecal matter hardens)- may result from insufficient fiber in diet </li></ul><ul><li>2 . Diarrhea – opposite of constipation– associated with intestinal disturbances caused by infections or stress– prolonged diarrhea may result in severe dehydration </li></ul><ul><li>3. Gall stones – small hard particles made of cholesterol which form & collect in gall bladder- may block the bile duct and cause pain </li></ul><ul><li>4. acid reflux -backflow of stomach contents upward into esophagus </li></ul><ul><li>5. appendicitis - inflammation of appendix </li></ul>