Though students have a general understanding of the human body by the time middle school rolls around, it is doubtful they truly grasp how many processes go on within us every moment. By tackling the subject of the human body using hands-on experiments and silly activities, the students can get a much better idea how the systems of the body work. For any activity with potential allergens (Potato Head) and physical activity (Heart Rate) check with students and parents first to ensure that participating in these activities is a healthy decision.

Potato Head

There is no better way to grasp an understanding for the human brain than to create one yourself. Students will use this activity to create a life-like model of their brains. The project requires 2 cups of sand, 1.5 cups of instant potato flakes, 2.5 cups of warm water and a few drops of red food coloring in a sealable 1 gallon plastic bag. Mixed together, the resulting lump is close to the color, size and weight of the adult human brain. Make sure each kid gets a chance to hold the plastic bag with the brain model. You can create a few "brains" at the beginning of the day and reuse them.

Heart Rate

At the beginning of the class, discuss how the circulatory system and the heart function. Teach students what a pulse represents and then show them how to take it at either the carotid (neck) or radial (wrist) artery with the index finger. Have the students take their pulses after sitting quietly for one minute. Then have the students exercise for one minute--for example, running in place, jumping jacks, bunny hops or shadow boxing. Have them take their pulses again and then have them plot the two numbers on a chart or graph. Attempt the activity several times and then have the students explain what happened when their pulses went up.

The Organ Trail

Divide students into groups and assign each group an organ. The groups must gather as much information as possible about the organ to create a wanted poster. Some of this information may include what the organ's functions are, what diseases affect the organ and which organ system the organ is contained in. This information can be gathered through books, in the computer lab or through diagrams that you may have set up throughout the classroom. A background for the wanted poster can be obtained at the Science Spot website (see Resource). Have a bulletin board set up so your students can post their wanted posters together.

Digestive System

Most students probably believe the digestive system is mostly composed of the stomach and this is where digestion begins. This activity shows them digestion starts in the mouth with the salivary glands. Have your students take two unsalted crackers and chew them for two minutes without swallowing. Have them write down their observations as to what begins to happen to the crackers. Explain to them how the teeth and saliva work together to break down food.