Constructing Hand Models
Second grade scientists have been learning how the bones, tendons, and ligaments in their hands work together to help them hold a pencil or grip the monkey bars. Each student built a working replica of a hand to cap off their learning about the skeletal system and muscles this month.
The hand study is part of a more extensive study of the major body systems this term in science. Students learned about the skeletal system and how bones work together with muscles and joints to support their bodies, allowing them to move in various ways. They also learned about some common types of joints, such as the ball and socket and hinge joints, building a replica of one kind of ball and socket joint, such as a hip or a shoulder, out of clay.
Students were given construction paper, drinking straws, and string to build their hands. First, they traced their own hand on construction paper and cut it out. They carefully bent each finger on the paper hand in the same place where their fingers bend and then used the folds to determine where to cut the straws representing the three bones in each finger and the two bones in their thumb. Students added longer straws to represent the bones that run between the fingers and the wrist and glued them to the paper hand. Utilizing skills learned in a recent math unit on measurement, each student measured the length of string they would need to run from each fingertip to the wrist and then added three inches. Once the string, which represents the tendons and ligaments, was threaded through the straws, students could use them to bend their fingers, make a fist, or pick up a light item.
Next, students will learn about the cardiovascular and respiratory systems. To document their learning this term, each student traced a life-size outline of their body on a large sheet of brown paper. As they learn about each successive body system, they will add its major components to their body sketch.