Six models and projects simulate human body systems. Fourth or fifth grade students then read passages on the circulatory, respiratory, digestive, nervous, muscular, skeletal, and immune systems. Three graphic organizers are included for each. Flash cards and assessment are included. Open the preview to take a closer look at the seriously fun science unit.For each human body system, students build a model. Directions and images are provided for each project.Circulatory – Students use two flexibl