In this unit, students investigate structures and functions of the human body. Students explore how our bones and muscles are interconnected, how our eyes interact with light and impact our vision, and how our brain responds to stimuli in our environment.
In this lesson, students discover the mechanism by which their muscles control their bones to move their bodies. In the activity, Robot Finger, students construct a model of a human finger and observe how pulling on a string (a model for tendons) causes it to bend at the joints.
We suggest students work in pairs. Homeschool students can work on their own, but may need a partner to help with a few steps.
Each student will need one piece of string that is 18 inches long.
Extend this Activity and Create Robot Hands
In the Extensions, we have a fun engineering extension activity where students combine four robot fingers to create a robot hand. We recommend having each group of four students assemble a hand using the robot fingers they each made.
In this lesson, students discover the basics of how their eyes work, and figure out some of the causes of vision problems. In the activity, Eye Model, students develop a working model of a human eye. They use a magnifying lens as a model of the cornea to explore how the structure of this lens is related to the function of our eyes.
As soon as you have a 3X magnifying lens, use it to make an image. For the best image, you need a dimly lit room and an interesting light source — like a window that lets light in, a lamp with a shade, or a television. Watch this short video for a demonstration.
After you’ve made an image, check to see what will work in your classroom. Do you have a door to the outside that you can prop open? A bright window? An interesting light fixture?
If you have a large class, you can set up a few stations with lamps around the room, or send students in batches to a window.
Hold On To The Eye Models
If you will be teaching the next lesson "How can some animals see in the dark?" , then you must save the eye models that students make in this lesson. Keep them in a safe place until you are ready to teach the next lesson.
In this lesson, students delve further into the workings of the eye, exploring the function of their iris and pupil. In the activity, Pupil Card, students add a smaller pupil to the eye model that they created in the previous lesson. Then they observe how the changing size of the pupil controls how much light enters the eye.
We suggest students work in pairs. Students need the complete eye model (magnifying lens and the index card “retina”) that they made in the previous lesson. If any students were absent for this activity, you can pair them with someone who has an eye model. Homeschool students can work on their own, but will need a partner for some parts of the activity.
Watch This Quick Video
In the first activity, students will experiment to see how their eyes change in response to changes in the light around them. Watch this video to see the change they are looking for. (You can also watch for this change in your own eyes. Look at your eyes in a mirror in a dark room and watch what happens when you turn on the lights.)
In this lesson, students explore the brain’s role in receiving information from the senses, processing that information, and controlling the muscles to enable movement. In the activity, Think Fast!, students test their reflexes with two very quick experiments and one more involved activity. They learn about how we process information in our brains and then respond to that information in different ways.