DIGESTIVE SYSTEM Organ overview Vocabulary Facts
Organs: The Mouth Breakdown of food begins in the mouth. Starches are broken down by an enzyme called salivary amylase.
Organs: The Esophagus The tube that connects the mouth to the stomach and also begins the process of peristalsis.
Peristalsis This is the esophagus Click HERE to see a super short claymation video of peristalsis
Organs: The Stomach A thick-walled muscular sac that contains enzymes and gastric juices (HCl). The enzyme Pepsin breaks down proteins in the stomach
The Stomach Interesting Fact: It takes approximately 12 hours to completely digest food.
Organs: Small Intestine Coiled tube about 20 ft. long and 2.5 cm. in diameter. Most digestion and ALL nutrient absorption is completed here. Lined with millions of tiny “fingers” called villi which increase surface area and aid in absorption of nutrients.
Small Intestinal Enzymes • Amylase, Maltase, Sucrase, Lactase • Continued breakdown of starches • Trypsin, Peptidase • Continued breakdown of proteins • Lipase • Breakdown of fats
Organs: Large Intestine • Tube about 5 ft. long and 6 cm. in diameter…No digestion occurs here! • Functions: • Reabsorption of water • Reabsorption of vitamins (K and B) created by E. coli bacteria! • Elimination of feces through the anus (stored in rectum)
Other Important Organs Liver: Produces bile which breaks down fat in the small intestine Gall Bladder: Stores bile Pancreas: Releases enzymes into the small intestine.
Pancreas Liver Gallbladder Small Intestine
MAIN IDEA Digestive System allows for food to be taken in, broken down into usable nutrients that can diffuse into cells to maintain homeostasis.
VOCABULARY use your text book to define these terms…. INGESTION DIGESTION ELIMINATION/EGESTION PERISTALSIS MECHANICAL DIGESTION CHEMICAL DIGESTION NUTRIETNT ABSORPTION VILLI CALORIE FECES Chyme
SOME FACTS INCASE YOU’RE ON JEOPARDY The human G.I. tract contains Approx. 2.2 lbs of bacteria Of these E. Coli is the most abundant, and show up only hours after birth!!! The average human eats over 1100 lbs of food per year and produces nearly 2 liters of saliva.
The Human Diet The average human should ingest about 2,000 Calories/day. This is less than you may think… Age, sex, lifestyle, weight, and body condition all affect daily Caloric needs.
Hungry? Let’s take a look at some popular eating establishments……. McDonalds or Red Robin you make the call……………..
A FEW FAST FOOD FACTS… A Big Mac sandwich = 540 calories Large Fries = 500 calories Large Soda = 300 calories Ketchup packet = 15 calories/each http://nutrition.mcdonalds.com/nutritionexchange/nutritionComparison.do Plain Bagel from Dunkin Donuts = 330 calories With cream cheese it has = 480 calories Medium coffee milk & sugar = 150 calories https://www.dunkindonuts.com/aboutus/nutrition/
RED ROBIN……. YUMMMM?? Below one of Red Robin’s more popular meals: All American Cheese Burger: 1315 Cal Stake Fries : 434 Cal Large soda : 290 Cal Total………………………….. 2039 !!! That’s right……. One meal here is more calories than the average person needs in one entire day……… yuummm
CHEW ON THIS……. AN EXTRA 200CALORIES EACH DAY EQUATES TO APPROXIMATELY 21 POUNDS OF WEIGHT GAIN PER YEAR!!!!
WANT EXTRA CREDIT???? • DO SOME BASIC RESEARCH, AND ANSWER THIS QUESTION: • IF HUMANS HAVE SO MUCH E. COLI LIVING INSIDE THEM EVERY DAY, WHY DO WE NOT GET SICK FROM THEM? • FIND THIS ANSWER AND WRITE YOUR HALF PAGE RESPONSE DOWN AND THE SOURCE THAT IT CAME FROM AND TURN IT IN BY FRIDAY DEC. 7TH