Second grade has learned a lot about the digestive system. We know that digestion is the process of breaking apart food read to be absorbed, and the digestive tract is the long passageway that food takes as it travels through the body. Students learned that digestion begins with the teeth and saliva. After we take a bite of food, and after the food is chewed and mixed with our saliva, the food travels down the esophagus. The Esophagus is the muscular “food pipe” that pushes down the swallowed food through the chest and into the stomach. Today, students participated in a fun activity where we used an esophagus model made of pantyhose and a tennis ball. The hose represented the esophagus, and the ball represented the food. Second graders used the esophagus model to demonstrate how the muscles contract (we used our hands as the muscles) to move the food down the esophagus and into the stomach. Next we discussed the stomach. The stomach is a j-shaped “expandable storage bag” that moves, twists, and squirms as it pours acids and enzymes on to the food….to break down food into smaller molecules. We also learned that our stomachs have a strong acid, hydrochloric acid, an important gastric juice that helps to kill germs that come in by accident by food or drink. This acid also helps to break down the food so that our bodies can easily absorb nutrients and vitamins. After discussing the stomach, students investigated with a fun hands on activity using a Ziploc bag, saltine cracker, water, and vinegar to use as a model of the stomach and what happens to food we eat. The clear bag represented the stomach. We broke up a saltine cracker and added water. The water represented the saliva in our mouth. We used two fingers to mash the food (representing what happens to food in our mouths as it travels down our throats and esophagus. Next we added vinegar to the bag. The vinegar represented the gastric juices and stomach acid. Students continued to mash the food from the bag with their two fingers. The stomach models demonstrated what happens to our food and what it looks like after it travels to our stomach. Last we discussed a very important curved triangle shaped organ (the second largest organ in our body), the liver. Though food does not travel through the liver, students learned that the liver has many important jobs in the digestion process…500 important tasks, in fact!! The liver deals with nutrients and stores vitamins and minerals. The liver also detoxifies harmful substances. It changes sugars into starches to store for later… and it breaks down starch to sugar if blood sugar levels are too low. The liver also makes bile (to help clean the blood) and also to help with digestion… it helps to break down fat! Who knew the liver was such an important organ?! Second graders are becoming digestion expert scientists… It’s fun learning more about our body!