How I Teach Medical ImagesSeeing Structure Before Function

Start by looking closely

I begin with the Medical Imaging Explorer. Students can examine X-rays, MRIs, and medical diagrams, zoom in, and use the markers to identify selected structures. The same-region comparison lets them place an X-ray beside an MRI of a foot, hand, or knee. The cross-section activity connects a simplified knee diagram with an MRI slice.

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For the opening, I keep the task small. I want students to compare a pair of images, identify a few structures, and record something they want to understand better. A prompt such as “Which structure can you identify, and what evidence supports your identification?” gives their exploration a purpose. Another useful question is “What becomes easier to see when you change images?”

This is also an opportunity to practice separating an observation from an interpretation. A student might notice a light region, a dark boundary, or a repeated shape. Identifying that region as a particular structure takes additional evidence. I can ask students to check a label, compare a diagram, or revise their description. Their first response becomes something they can develop as the lesson continues.

Give the reading a clear purpose

From there, we move into the reading. I am using the Core Knowledge Foundation's Cells and Systems: Science Literacy Student Reader, specifically PDF pages 16–20. In this edition, those are printed pages 12–16, covering “Mending Broken Bones” and “Imaging Injuries.” Teachers can access the original reader on Core Knowledge's website.

I chose this selection because the visual presentation gives students several ways into the content. It includes illustrations and photographs of injury supports, medical images, a short narrative, and explanations paired with visuals. The reading connects the images students have just explored with situations in which people need information about the inside of the body.

This is how I like to use a supplemental text: selectively and with a clear purpose. I can choose a few pages that support the question we are working on and fit them into the larger OpenSciEd learning sequence. Here, the reading gives students something concrete to revisit, discuss, and use as evidence. The photographs, diagrams, and captions are part of that work.

Reciprocal teaching gives students a way to respond while they read. I organize that response around four moves: predict, question, clarify, and summarize. A simple four-part organizer or notebook entry can hold their thinking. Prompts like these give students a place to start:

• Predict: Use a heading, image, or the section you just finished to predict what information might come next. Explain the clue behind your prediction.
• Question: Write a question about a body structure, an image, or something the reading leaves you wondering. Point to the detail that prompted it.
• Clarify: Identify an unfamiliar term or a confusing part of an image. Use the surrounding text, captions, and discussion to improve your explanation.
• Summarize: State the main idea of a short section in your own words and include one supporting detail from the words or visuals.

I break the selection into manageable sections, with a brief pause to write and discuss between them. Students can compare questions, explain a caption to one another, or revisit an initial prediction. Each student still needs a record of their own thinking. The discussion should help them refine that record.

The clarification step is especially useful here. A student may read a paragraph fluently and still be unsure how it connects to the image beside it. Asking them to identify that uncertainty gives me a specific place to help. I can also model how to return to the text when a response needs stronger evidence.

Name the parts. Describe the organization.

After the reading, I bring the class together for the mini-lesson. By this point, students have images, examples, and written responses we can refer to. I use those shared references to introduce the language more explicitly.

I describe a structure as an identifiable part. When we describe its structure, we pay attention to how it is built: its shape, material, arrangement, and connections. In a body image, that might mean identifying a bone, locating it relative to another bone, or describing the visible boundary between different tissues.

I introduce a system as a set of connected or interacting parts considered together. A subsystem is a smaller system within a larger one. The human body can be studied as a system, and the skeletal system can be considered one of its subsystems. Individual bones are structures within that subsystem. A smaller part is not automatically a subsystem; the term depends on whether we are examining an organized set of parts within a larger system.

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I sketch this relationship on the board and connect it to an image students already explored. A foot or knee image is useful because it can show structures associated with more than one body system. The boundaries of the picture are not necessarily the boundaries of a system.

At this stage, I keep our explanations centered on identifying parts and describing their organization. Students may already have ideas about what those parts do, and we can save those questions for the next stage of the unit. Today's target is a clearer account of the structures we can identify and the larger systems they belong to.

Bring the evidence together

As I read those responses, I am looking for precision. Can a student move from “there are things inside your body” to identifying a particular structure and explaining where it belongs? Can they support that explanation with something they observed or read? Those responses will help me decide what needs another example before we begin connecting structure to function.

The next lesson can build on the parts and relationships students have established here. We will have shared images to return to, useful language in our notebooks, and questions ready for the next investigation.