A Walk Through the Gut
This simulation helps students understand what happens to food as it passes through the digestive system. The student has a 3x5 index card representing food, which he / she carries to stations around the room. Each station creatively represents one of the organs of the digestive system. At each station the student is given a specific instruction to "digest" the index card and then instructed to "proceed to the next station". At the end of the simulation, students form cooperative learning groups to analyze and apply the results of the simulation to the human digestive system.
BACKGROUND INFORMATION -- for the TEACHER
This simulation works best after the students have been introduced to the structures and functions of the digestive system. It works well if students visit each station singly, then form groups of three to analyze simulation; or if students visit the stations in pairs, then form learning groups of 4. The teacher can assemble the stations or the students can be assigned the organs( see ALTERNATE PLAN).
BACKGROUND INFORMATION -- required of STUDENTS
Students should have general knowledge of the structures of digestion, the sequence in which food moves through these organs, and the general digestive functions of the organs.
If teacher collects and assembles stations, including directions for each, about one hour. See (ALTERNATE PLAN) for student time.
For a class of 30: the stations took 20 minutes and the analysis questions required 30 minutes.
Each of the following digestive structures is represented by a "functional" construction, container, or diagram which is limited only by your creativity (see ALTERNATE PLAN). Each digestive structure is labeled with name, (function) and the directions for the students to "digest" his/her food.
MOUTH: digestion of food begins (starch)
ESOPHAGUS: food passes to stomach
STOMACH: digestion continues (protein)
GALL BLADDER: emulsion
SMALL INTESTINE: continuing digestion & absorption (nutrients)
LARGE INTESTINE: absorption (water & minerals)
RECTUM: remaining food passes to anus
ANUS: exit of undigested food
STRUCTURE/CREATIVE CONSTRUCTION SUGGESTIONS
MOUTH: drawing-mouth, teeth, protruding tongue which lifts
ESOPHAGUS: 4" diameter dryer exhaust vent hose
STOMACH: hot water bottle with ends removed, scissors inside
GALL BLADDER: green balloon with scissors attached by string
SMALL INTESTINE: string shopping bag, both ends open (or basket ball net) with scissors inside,inside clear garbage bag
LARGE INTESTINE: large cylinder of paper set in specimen bowl with scissors inside
RECTUM: slinky atop shoe box
ANUS: shoe box with circle cut into lid, under slinky
STRUCTURE: DIGESTIVE DIRECTIONS
MOUTH: (under tongue) digest by tearing food into 2 equal pieces
ESOPHAGUS: pass food through by peristaltic motion
STOMACH: digest only 1 piece of food by cutting it into 2 equal pieces
GALL BLADDER: cut the 2 smaller pieces into 4 pieces
SMALL INTESTINE: digest the 4 small pieces of food into 8 smaller nutrients. Place all pieces in the mesh bag, push through the mesh (and into the clear garbage bag) only those pieces that fit without folding or bending. (The large piece of food moves to the next station)
LARGE INTESTINE: cut one corner from remaining food and it leave in bowl
RECTUM: write your name on the remaining food and deposit in the rectum
ANUS: leave undigested food
PROCEDURE/ DESCRIPTION OF LESSON
Each student (pair) receives a 3x5 card representing food. This food is carried to each digestive structure station where the student follows the digestion directions, and takes food to the next sequential station. At the conclusion of the walk through, the student has deposited the "undigested" food with his / her name on it in the anus. The students then form cooperative learning groups to discuss and answer the questions.
- What does every cut or tear represent? List the structures of digestion and whether the food is digested physically, chemically (or both) in that structure.
- What does each piece of the index card that is cut represent? For each digestive structure, list the nutrient(s) that are digested there.
- What does each piece of card which is left at the station represent? Where do these nutrients go? For each digestive structure, list the structure and which nutrient(s) are absorbed there.
After students have discussed and answered the questions (and had their papers stamped), they may use the resource materials to revise their answers.
METHOD OF EVALUATION
- If each student (pair) has followed the simulation directions, there will be an identical piece of "food" with their name on it in the "anus". Points are given for correct procedure.
- Each student has written answers to the group questions. Select one from each group, grade, and give points to all members of group. (You may choose to grade the group papers before the students revise them).
The day before the simulation, students work in cooperative groups with one assigned structure. They must research its functions, decide on a way to creatively represent that structure, and write the digestion directions. (You must give the proviso that reduction of the food can only take place one cut per station). Their homework is to construct the structure. On the day of the simulation, the group must place its structure and directions at the correct sequence station. The simulation may not proceed smoothly , so each group must analyze what stations were in conflict, and propose a set of directions which will allow consecutive digestions of the index card.
EXTENSIONS AND REINFORCEMENTS
Extension: Students may research and list the specific digestive enzymes and their substrates for each digestive structure.
Reinforcement: Students select their favorite food (tacos were big last year) and trace it through the digestive system. They can write, graphically organize, or draw the process.