To understand that there are different systems within the body and that they work independently and together to form a functioning human body.
At this level, children can begin to view the body as a system, in which parts do things for other parts and for the organism as a whole. Through the use of an online interactive activity, children learn about the concept of separate components working together to build a body system. In addition, this lesson focuses on activities to help students learn that body systems work together to build the functioning human body. This lesson could be used in conjunction with instruction on the human body and/or systems.
In order to be able to do this lesson, students should understand that most items are composed of different parts and that an item may not work if its parts are missing. Also, they should know that an assembly of parts can perform functions that the single parts cannot perform alone. More specific to the human body, students at this level should realize that the human body has parts that help it seek and take in food when it feels hunger. They should understand that the brain is the part of the body that enables humans to think and it communicates with the other parts of the body.
This prerequisite knowledge should help elementary-school students understand that parts within a system usually influence one another and that a system may not work as well, or at all, if a part is missing, broken or worn out, or misconnected. In addition, they should be able to make correlations about systems in general to systems of the human body. Specific to the human body, students should understand the following: by eating food, humans obtain energy and materials for body repair and growth; by breathing, humans take in the oxygen they need to live; by communicating with all parts of the body, the brain understands what is going on at different parts throughout the body; and the skeleton provides the body with structure and protection.
Research indicates that elementary students may believe that a system of objects must be doing something (interacting) in order to be a system and/or that a system that loses a part of itself is still the same system. (Benchmarks for Science Literacy, p. 355.) Research shows that student misconceptions about systems arise from their difficulty in recognizing that a natural phenomenon (e.g., the human body) occurs by systems working independently and together (e.g., circulatory, respiratory, nervous, digestive). Studies of student thinking show that, at all ages, they tend to interpret phenomena by noting the qualities of separate objects rather than by seeing the interactions between the parts of a system.
For upper elementary-school students, research specific to the human body indicates that, in terms of internal bodily organs, upper elementary students are able to list a large number of organs. In terms of the nervous system, they know the brain helps the body parts but do not always realize the converse (that the body helps the brain). They do know, however, that nerves conduct messages, control activity, and stabilize the body. Upper elementary students do not understand the brain's role in controlling involuntary behavior. In terms of the digestive system, once students reach the fifth grade, they know that food undergoes a transformation process in the body. In terms of the respiratory system, they associate the lungs' activities with breathing. Further, they may have some knowledge about the exchange of gases in the lungs and understand that air goes to all parts of the body. In terms of the circulatory system, upper elementary-school students realize that the heart is a pump, but they do not realize that the blood returns to the heart.