Systems of the Human Body

What You Need


  • Paper and pencil
  • Poster board
Systems of the Human Body


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. (Benchmarks for Science Literacy, pp. 344-345.)


Questions about familiar body systems can be useful in getting students to start thinking about systems in general. This process can initiate the understanding that each organ affects and is affected by others.

Hold up an apple (or some other healthy snack). Ask students:

  • What am I holding in my hand?
  • If I were going to eat this apple, what parts of my body would I use?

Have students discuss the body parts we use when biting, chewing, swallowing, and digesting an apple. You may want to create a chart on the blackboard or a large sheet of paper to record students' ideas. If so, you can use these categories to help you organize the information:

  • Body Parts for Biting
  • Body Parts for Chewing
  • Body Parts for Swallowing
  • Body Parts for Digesting

Now ask students:

  • How do the different parts work together? (Each part plays a special role, so once one task is accomplished, then the next part can perform it's role.)
  • What happens if one of the parts is missing? (For example, if the teeth were missing, then it would be difficult if not impossible to chew some foods, and if one couldn't chew something large to get it small enough to pass through the esophagus, then they could choke.)

Continue to guide student understanding of systems by asking:

  • Who remembers what it's called when a number of different parts work together to make something happen or function? (Guide students so that they come up with system as an answer.)
  • Can you think of an example of a system? (Some possible examples are a bicycle, a computer, a school, or a bus.)
  • For the system you picked, write down any parts that belong to that system. (For example, some parts that are necessary for a bicycle are two wheels, gears, brakes, foot pedals, and handles.)


Now have students use the All Systems Go! student esheet to access the All Systems Go! interactive. This activity requires students to drag organs of different body systems into the human body cartoon (Arnold) classifying them according to certain systems (digestive, skeletal, circulatory/respiratory, and nervous). For each system, once the correct organ is placed into the body, it will stay there. However, if an incorrect organ is placed into the body, all the organs will move out of the human body (Arnold) and the student will have to start over for that body system. Once all of the correct organs for a body system have been placed within Arnold, the next organ system will automatically appear at the bottom of the screen. When all four systems are done, the clothed Arnold will reappear.

The student esheet includes both instructions on how to play the interactive activity and questions regarding the activity. Answers to the questions can be found in the activity and in the Learn More section on this site. To answer the questions students can use the All Systems Go! student sheet.

  • What body system helps humans turn the food they eat into energy? (Digestive.)
  • What body system helps humans breathe? (Respiratory.)
  • What body system controls other body systems? (Nervous.)
  • What body system provides structure for the body? (Skeletal.)
  • What body system allows us to move? (Muscular.)
  • What body system includes a transport system (blood) and a pump (the heart) that keeps the transport system moving? (Circulatory.)
  • Can you think of two body systems that work together? (Examples include the respiratory and circulatory, muscular and skeletal, digestive and circulatory, and nervous and any other system.)
  • What part of the nervous system is essential for it to work properly? (Brain.)
  • What event could disrupt one or more body systems? (Injury or disease could disrupt one or more body systems.)
  • What parts of the respiratory system would need to be blocked to not allow any air into this system? (The mouth, nose, or trachea.)

This activity should help teach students that organs within a system work together to make that system function, and it should be pointed out that in turn all systems function together to make the human body function.

At this point, ask students to name any other body systems. See how many systems they can generate on their own and fill in the gaps where necessary. The primary focus of this lesson is the digestive, respiratory/circulatory, skeletal, muscular, and nervous systems.

Body systems covered: Other body systems:
Digestive Urinary
Circulatory/Respiratory Skin
Skeletal Reproductive
Nervous (includes the 5 senses)  

Note: Students should focus on the fact that systems work together not necessarily on the names of each organ.


The main point of this lesson is to understand that there are different systems within the human body and that these systems work independently and together to form a functioning human body.

Ask students to revisit the questions from the Motivation that they answered before they did the online interactive activity (see the first two questions below). They should answer them again with their new knowledge and then answer the third question. Give students five to ten minutes to do this and then have them share what they wrote down before and after doing the online interactive.

  • Who remembers what it's called when a group of things function together as a whole?
  • Can you think of an example of a system? For that system, name some of its parts.
  • What six body systems did you learn about in this lesson?

Next, ask students to hypothesize about what might happen if part of a body system were missing. Once they've come up with their theories, have students create a poster of a body system working properly and one that is not because it is missing one or more of its parts. When they are done with their posters, have students share them with the rest of the class. Students can view each others posters and discuss the different systems.


Innerbody provides in-depth coverage of ten body systems. It includes clickable body diagrams with many components of each body system.

Your Gross and Cool Body reviews body systems via gross and cool things that your body does (e.g., burps, gas, ear wax, etc.).

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Lesson Details

Grades Themes Type Project 2061 Benchmarks