Year 4 – The Digestive System
In Year 4 we have been learning about the digestive system and its function. We recreated the digestive system and discussed how food passes through our bodies.
Step 1 [mouth]: We put a cracker into a zip-lock bag. We started crushing it up to represent the teeth. Our mouth then produces saliva. So we added water to the bag to represent this. The food then travels down the oesophagus.
Step 2 [stomach]: The stomach has acid and digestive juices that break down the food. So we added orange juice to the bag to represent this. We continued to gently squeeze the bag to represent the stomach churning the food to break it down. This is completed in the duodenum.
Step 3 [ileum – small intestine]: In the small intestine, proteins, fats and vitamins are absorbed from the food. The walls of the ileum are lined with tiny finger like villi expanding the surface area so it can absorb more. We ran our fingers over to represent the finger like villi absorbing the proteins, fats and vitamins.
Step 4 [colon – large intestine]: In the large intestine, it absorbs the water from the remaining waste to be used by the body before it is excreted through the anus. We poured the stomach contents into a pair of tights. The liquid passed through the tights and was absorbed by the paper towel, leaving only the waste.