The Digestive System

Finishing my plant functions and structures unit last week led me to believe that I was going to have a break from teaching science for about a week, however, I ended up starting a whole new mini-unit on digestion. The unit was only 3 lessons on digestion and it AMAZING. This was a great mini-unit because one of the reasons that I felt it was extra special was that we had a hands on lab each day which does not ordinarily happen in a fifth grade class.

The mini-unit began with a general lesson on what the digestive system is, its parts, and we discussed why it is important. This was just a 45 minute lesson where the students were introduced to the digestive system, they labeled a diagram, color coded it, completed a mini-lab with their table mates on how the digestive system absorbs nutrients-this is where the students tested different types of paper to find which was the most absorbent. Toilet paper won- which we then related the toilet paper to the small intestine and how its' folds and texture(hair-like structure) lends itself well for absorption.

The next day was a lab on the mouth and teeth(the beginning of the digestive system) where we discussed physical and chemical breakdown, how it begins, what is occurring when chewing, etc. The students were each given one piece of gum and worked as a table to weigh(using a scale and weights) the gum before chewing, then they were timed for 10 minutes, and they weighed their gum again(they placed it back in the wrapper). This was a great lab because the students were really engaged and interested. Lastly, we did a "Stomach In A Bag" lab where the students actually were able to simulate the chemical and physical

properties of the digestive system. The lesson began with the students placing food in a bag with water. They squeezed the bag initially, then after five minutes, and again for ten minutes while observing the entire time. This was the most energetic, yet also the most engaging lesson- the students were very excited to mimic the stomach muscles, and truly took a lot out of this activity.

As we closed the mini-unit, they were able to recite the parts of the digestive system(mouth, esophagus, sphincter, stomach, small intestine, large intestine, colon, rectum, anus) without a diagram or book. They were also able to identify the two methods that food are broken down(physical and chemical), and lastly and most importantly they were able to explain what our digestive system produces for us(energy). It was a great unit and my enthusiasm for science and passion for teaching continues!