2Digestion LabWe are going to use household items to model the digestive system.
3Digestion LabSubstances in food that provide raw materials and energy the body needs to liveOur digestive system turns the chemical energy in these nutrients into energy we can use
4Digestion Lab Procedure 1. Label four plastic sealable bags with the following:protein (lunchmeat)vegetable (lettuce) starch (crushed cracker)dairy (cheese)
5Digestion Lab Procedure 2. Use a cotton swab to lightly coat the inside of the bag with vaseline.Measure out 60 mL of vinegar in agraduated cylinder and pour into the bag
6Digestion Lab Procedure 4. Add 1 drop of food coloring to one side of the bag so the drop slidesdown the vaseline.Using the balance, mass 10 g of your groups food item.6. Add the 10 g of food to the correct bag and seal.
7Digestion Lab Procedure 7. Shake the sealed bag from side to side 50 times.8. Compare each bag and make an inference about how fast each is “digesting”9. At the end of the period, make sure the bags go in the trash.
8Digestion Lab Questions. Write these answers in your spiral: Which food type was digested thefastest? ______________________2. Which food type needed more digesting time? _________________
9Digestion Lab Questions. Write these answers in your spiral: 3. What did the plastic bag represent in this model?______________________4. What did the vaseline represent in this model?__________________________
10Digestion Lab Questions. Write these answers in your spiral: 5. What did the vinegar represent in this model?______________________6. What is at least one limitation of this model? _________________________
11Stomach and Intestine Slides Now using the microscopes. Look at the slides labeled stomach and small intestine.In your spiral, diagram what you see.
12Organs of the Digestive System Mouth RectumEsophagus AnusStomach PancreasSmall intestine Gall BladderLarge intestine Liver
14Functions of the Digestive System Digests food into molecules the body can use (physical or chemical change)Absorbs nutrient molecules and carries them around the body (physical change)Eliminates waste material from unused nutrients
15Digestion body breaks down food into small nutrient molecules mechanicalchemical
16Mechanical DigestionFood is physically broken down into smaller piecesBegins in the mouthTeeth chewing/tearingMovement ofsmooth muscles
17Chemical DigestionChemicals produced by the body break foods into their smaller nutrientsmouthstomach
18AbsorptionProcess by which nutrient molecules pass through the wall of your digestive system into your bloodThe lining of the small intestine is covered in villi that aid in absorption
19Elimination Materials that are not absorbed leave the body as waste The waste material left over after food is digested must leave the body to prevent illness
20Which is not a function of the digestive system? Breaking down food into molecules the body can useAbsorbing food molecules into the blood to deliver to the bodyChanging waste into molecules the body can useEliminating undigested waste from the body
21Mouth Digestion begins in the mouth Mechanical – teeth Chemical - saliva
22Esophagus Muscular tube that connects your mouth to your stomach moves food down into your stomachusing involuntary musclecontractions (peristalsis)Lined with mucus thatallows food to slide down
23The Stomach J-shaped muscular pouch Most mechanical digestion takes place in the stomachChemical digestions also takes placeStomach secretes digestive juice (enzymes) that break down foodAverage adult stomach holds 2 litersMucus keeps the acids from burning a hole in your stomach
25ModelingPlace the marble in the end of the tube and squeeze it down into the balloon.
26Modeling What do you think this could be a model of? What is the tube? What is the balloon?What is the marble?What is the soap?esophagusstomachfoodsaliva and mucus
27Which is not an example of mechanical digestion? Teeth chewing foodTongue breaking up foodSmooth muscles in stomach churning foodHydrochloric acid breaking down proteins
28Small Intestine Where most of the chemical digestion takes place Where most of the absorption takes placeCovered in villi whichenlarge the surface area
29Small Intestine Most digestion happens here. Intestinal juice (full of enzymes)breaks down food.Digestive HelpersLiver, Gall bladder, PancreasDigested food is absorbedthrough the villi into a network ofblood vessels that carry thenutrients to all parts of the body.e) By the time food leaves the small intestine, it is empty of all nutrients except water.
30Small IntestineThe villi increase the surface area that can absorb nutrients
31Where does most digestion take place? MouthStomachSmall intestineLiver
32Liver Breaks down medicines and other chemicals Produces bile that breaks up fat particlesThe gall bladderstores bile
33Pancreas Produces enzymes that flow into the small intestine Secretes insulinCauses diabetes when it does not make insulin
34Large Intestine Last section of the digestive tract Food spends hours hereWhere water is absorbedVitamins B & K are made by bacteria in the large intestine
35Rectum and AnusRectum – end of the large intestine, forms the solid wasteeliminationAnus – muscular opening at the end of the rectum
36Which cell parts are like the digestive system? Which one makes energy?mitochondriaWhich one allows materials to pass in and out?cell membraneWhich one helps get rid of waste?lysosomes
37The Digestive System Interacts with: muscular system (smoothmuscle) to move and digest foodrespiratory system to provideoxygencirculatory system to movenutrients