Skeletal System Functions Lesson Plan (TEKS 7.13A): A Complete 5E Lesson for Bones, Joints, and How the Skeleton Supports the Body

Chris Kesler · 10 min read

The first time I taught the skeletal system to a room of 7th graders, I made the mistake of asking, "What do your bones do?" Hands shot up and I got "hold you up" about fifteen times in a row. Nobody mentioned protection. Nobody mentioned blood cells. Nobody mentioned calcium storage. To them, the skeleton was a coat rack. End of story.

What flipped it was the day I brought in a clean chicken bone, snapped it in half in front of the class (with a little theater), and showed them the red marrow inside. "That's where your blood is made." Silence. Then a flood of questions. Once they realized the skeleton was alive, doing five jobs at once, every conversation about bones got sharper. They started asking why babies have more bones than adults and how the femur could be stronger than concrete. The vocabulary stopped being a list and started being a story.

That's the core idea behind this 5E lesson for TEKS 7.13A. Students don't just memorize the parts of the skeleton. They explore the five main functions of bones, build joint models with their hands, and walk away understanding that the skeleton is one of the busiest, most interconnected systems in the body.

⏱ About 10 class periods 📓 7th Grade Life Science 🦴 TEKS 7.13A 🎯 Differentiated for D + M 💻 Print or Digital

Inside the Skeletal System Functions 5E Lesson

The 5E instructional model walks students through five phases: Engage, Explore, Explain, Elaborate, and Evaluate. It flips the traditional lecture-first sequence on its head. Students explore a concept hands-on before you ever explain it, which means by the time you do explain it, they have something to hook the vocabulary onto.

I switched to the 5E model years ago and stopped going back. Kids retain more, ask better questions, and stop staring at me waiting to be told the answer. The Skeletal System Functions 5E Lesson is built on this framework from start to finish. Here's how it plays out across the five phases.

🎯 Engage

I CAN statement and key vocabulary for the skeletal system functions lesson

Day one is a teacher-led hands-on exploration. Each small group gets a labeled diagram of the human skeleton, a stack of "function cards" (Support, Protection, Movement, Blood Cell Production, Storage), and a set of organ cards (heart, lungs, brain, spinal cord). Following the teacher directions, they work through the activity by matching bones to the organs they protect, then sorting their thinking by which function of the skeleton each example demonstrates.

By the end of the period, kids have the diagram annotated, a sketch of the five functions in their student sheet, and they can explain in their own words why the skeleton is so much more than "the thing that holds you up." Nobody has heard a vocabulary lecture yet. That's the point. They walk into the rest of the unit with a working model of what the skeleton actually does, not a memorized list.

What's included in the Engage:

Teacher directions for the hands-on skeleton sorting activity
Printable student observation sheet
Answer key for the discussion questions
Four learning objective slides (standard verbatim, "Describe" verb highlighted, "I CAN...", and "WE WILL...")
An illustrated Body Systems Word Wall in English and Spanish covering the full unit vocabulary

🔬 Explore

📷 Explore image 1 — wide shot of Station Lab in action

The Skeletal System Functions Station Lab is the heart of the Explore phase. Students rotate through 8 stations (plus a 9th challenge station for early finishers) over one class period. The Station Lab is split into four input stations (where kids take in new information) and four output stations (where they show what they learned).

The four input stations:

🎬 Watch It! — Students watch a short video on the structure and function of the skeletal system and answer guided questions about bones, joints, and marrow.
📖 Read It! — A one-page reading passage at two differentiated levels, with a Spanish version included.
🔬 Explore It! — Students build working joint models (hinge, ball-and-socket, pivot) out of straws, brass fasteners, and clay, then test the range of motion of each one.
💻 Research It! — Reference cards on the five functions of the skeletal system, the difference between the axial and appendicular skeleton, and common bones to know.

The four output stations:

📋 Organize It! — A card sort where students place bones (skull, ribs, vertebrae, femur, humerus, pelvis) into the axial or appendicular skeleton and justify their choice.
🎨 Illustrate It! — Students draw a labeled diagram of a long bone showing the marrow cavity, compact bone, and spongy bone, then label what each region does.
✍️ Write It! — Three open-ended questions in complete sentences (this is where you see who really gets the five functions).
📝 Assess It! — A short formative check with multiple choice and a fill-in-the-blank vocabulary paragraph.

📷 Explore image 2 — close-up of featured station (Explore It! or Organize It!)

Print and digital versions are both included. If you want the full breakdown of what happens at every single station, what students produce, and how to set it up, that's in our dedicated Station Lab post.

→ Read the full Skeletal System Functions Station Lab walkthrough 8 stations, materials list, teacher tips

The Station Lab is included in the full 5E lesson. You don't need to buy it separately if you're getting the whole unit.

📚 Explain

📷 Explain image 1 — Presentation slide screenshot

Here's the real payoff of doing the Engage and Explore before the Explain: by the time kids hit this phase, they've already sorted bones by function and built joint models with their hands. They have a working understanding before you ever start naming things. The discussions get deeper, the questions get sharper, and you spend less time defining and more time pushing their thinking.

The Skeletal System Functions Presentation walks 7th graders through the full scope of TEKS 7.13A for this system, one concept at a time. The deck opens with the big question: what does the skeleton actually do? Students learn that the skeletal system has five main functions. Support gives the body its shape and provides the framework that softer tissues attach to. Protection shields the body's internal organs. The skull guards the brain, the rib cage guards the heart and lungs, and the vertebrae guard the spinal cord. Movement happens because the skeleton gives skeletal muscles something to pull against at the joints. Blood cell production happens inside the red bone marrow of certain large bones. Storage of minerals like calcium and phosphorus, plus chemical energy in the form of fatty acids in yellow marrow, keeps the body's homeostasis stable.

📷 Explain image (middle) — Presentation slide screenshot (classification hierarchy, Essential Question, or category comparison)

From there the deck zooms in on bones themselves. An adult human skeleton has 206 bones, and they're not the dry sticks kids picture from Halloween decorations. Bones are living organs with blood vessels, nerves, and cells that constantly remodel themselves. The deck breaks the skeleton into the axial skeleton (skull, vertebral column, ribs, sternum) and the appendicular skeleton (arms, legs, pelvic girdle, shoulder girdle). Students see how every bone fits into one of those two categories. Then we get into the structure of a long bone like the femur: the compact outer layer for strength, the spongy bone for shock absorption, and the marrow cavity where blood cells are made. One slide always gets a reaction: the femur is technically stronger than concrete by weight. 7th graders love that fact.

Then the lesson tackles joints, which is where the skeletal system gets its movement job done. A joint is anywhere two bones meet, and not all joints work the same way. The deck walks through the four main types: hinge joints (elbow, knee) move in one plane like a door. Ball-and-socket joints (shoulder, hip) rotate in nearly any direction. Pivot joints (neck) rotate around a single axis so you can shake your head no. Gliding joints (wrist, ankle) slide past each other for small fine-motion movements. The deck includes a built-in matching activity where students drag joint types to the right body location. Once kids see that the type of joint determines the movement, the skeletal-muscular connection clicks.

📷 Explain image 2 — Presentation slide screenshot

The deck closes by tying the skeletal system back to the other body systems it works with. The skeletal and muscular systems work together to create movement. The skeletal and circulatory systems work together because bone marrow makes the blood cells. The skeletal and nervous systems work together because the skull and vertebrae protect the brain and spinal cord. That kind of cross-system thinking is exactly what TEKS 7.13A is asking for.

What makes the Skeletal System Functions Presentation different from a typical body-systems slideshow is that kids are doing something on almost every slide. It's not a lecture deck. It's a participation deck. "Your answer:" prompts appear on most slides, Brain Breaks reset attention every few slides, and Quick Action INB tasks (joint matching, bone sorting, function mapping) show up throughout. Think About It prompts push deeper into bigger ideas like how an astronaut's bones change in zero gravity and why teenagers need extra calcium. The deck closes with a Check for Understanding tied back to the Essential Questions: What are the main functions of the skeletal system? and How does the skeleton interact with the other body systems?

The Explain materials in this product include:

An editable Presentation at two differentiated levels (Dependent and Modified), works in PowerPoint or Google Slides
A guided fill-in-the-blank student notes handout that mirrors the Presentation, with answer key
A Paper Interactive Notebook (English and Spanish) students cut, fold, and glue into their notebooks
A Digital Interactive Notebook at both levels with answer keys, for 1:1 classrooms or Google Classroom

The Explain runs across two class periods. The built-in Think About It prompts are where the real discussion happens, so let those breathe.

🛠️ Elaborate

Student choice project options and rubric for the skeletal system functions lesson

The Elaborate phase is where students stretch what they learned about the skeletal system and put it into a project of their choosing. In this 7th grade life science lesson, that's a Student Choice Project board with six different project options plus a "design your own" pathway.

Students might build a 3-D model of a joint and demonstrate how it moves, design an "infographic" of the five functions of the skeletal system with real-world examples, write a short story from the point of view of a red blood cell being born inside the bone marrow, or record a video tour of the human skeleton naming bones and the organs they protect. There are options for kids who love to write, kids who love to draw, kids who love to build, and kids who love to perform. Whatever the project, the point is the same: students apply the five skeletal functions and the relationships between systems to a real-world artifact instead of a worksheet.

Choice is the whole point. By letting students pick how they show their thinking, you get more authentic work for TEKS 7.13A and you actually get to see what they understand about the skeletal system.

The rubric (the part teachers actually want)

Every project, no matter which option a student picks, is graded on the same rubric. Five categories at 20 points each:

Vocabulary (20 pts) — At least four words from the lesson are used in context.
Concepts (20 pts) — At least two key concepts from the lesson are referenced.
Presentation (20 pts) — The project grabs attention and is well-organized.
Clarity (20 pts) — Easy to understand. Free of typos.
Accuracy (20 pts) — Drawings and models are accurate. The science is right.

The rubric uses a minus / check / plus shorthand on every row so you can grade a stack of projects quickly without re-reading every criterion.

Two differentiated versions in one file

The standard version is for students ready for independent application of skeletal system ideas. The Reinforcement version is for students who need additional vocabulary or concept support. Three of the six options are swapped for projects with a tighter vocabulary tie-in, and "design your own" is replaced with "collaborate with the teacher" so kids aren't pitching cold.

✅ Evaluate

The Evaluate phase wraps the unit with a formal assessment. It's not all bubble-in. Several questions show students labeled diagrams and joint images and ask them to identify the function, the type of joint, or the interaction between body systems.

The full assessment has 12 questions across five formats:

Multiple choice (4 questions) covering the five functions of the skeletal system, axial vs. appendicular skeleton, joint types, and bone marrow
Hotspot / visual (2 questions) where students click the femur on a skeleton diagram and identify the part of a long bone where blood cells are made
Multiselect (2 questions) where students pick all of the bones in the axial skeleton, and all of the structures that protect internal organs
Short answer (2 questions) on how the skeletal system supports and protects the body, and on how the skeletal and muscular systems work together at a joint
Multipart scenario (2 questions) with a real-world example (a student who breaks an arm) where students identify the broken bone, the type of joint nearby, and the function of marrow during healing

A modified version is included for students who need additional support. Fewer multiple-choice distractors and sentence-starter scaffolds on the short-answer items.

If you've taught all five phases, this assessment shouldn't surprise anyone. It's a chance for kids to show you they get it.

How everything fits together

If you want the whole experience (Engage hook, the Station Lab as the Explore, the Explain day with Presentation and interactive notebook, the Student Choice Elaborate, and the Evaluate assessment all in one download), that's the Skeletal System Functions Complete 5E Science Lesson.

If you only need the one-day hands-on activity, the Station Lab works as a standalone. Most teachers buy the full 5E because the Station Lab works harder when it's bookended by a strong Engage and a follow-up Explain. But both are honest options.

Two options

Skeletal System Functions Complete 5E Lesson cover

Full 5E Lesson — ~10 class periods $13.20 Get the 5E Lesson

Skeletal System Functions Station Lab cover

Just the Station Lab — 1–2 class periods $7.20 Get the Station Lab

What you need to teach Skeletal System Functions (TEKS 7.13A)

Materials beyond what's in the download:

Printed skeleton diagrams and function cards for the Engage activity (templates included)
Straws, brass fasteners (brads), and clay or playdough for the Explore It! joint-modeling station
Index cards for the axial vs. appendicular bone sort at the Organize It! station
Pencils, colored pencils or markers, and printed student pages
A device with internet for the Watch It! station and the slide deck

Standard covered: Texas TEKS 7.13A — Describe the function and interactions of major body systems in organisms, including the skeletal, muscular, nervous, respiratory, integumentary, circulatory, endocrine, digestive, immune, and urinary systems. See the full standard breakdown →

Grade level: 7th grade science

Time: About 10 class periods of 45 minutes each, done with fidelity. The product also ships with a compressed sample unit plan if you need to move faster.

Common misconceptions this lesson clears up

"Bones are dead"
This is the most common one I hear, and I get it. The skeletons hanging in science classrooms are dry, hollow, and clearly not alive. But living bone is a completely different story. Bone is a living organ packed with blood vessels, nerves, and cells called osteoblasts and osteoclasts that constantly break down and rebuild bone tissue every day of your life. Inside the marrow, your body is cranking out millions of new red blood cells every second. Bones grow when you grow, heal when they break, and even change shape based on the forces you put on them. The skeleton in the corner of the classroom is dead. The one inside you is anything but.
"All joints work the same way"
If all joints worked the same, you couldn't do half the things you do every day. Hinge joints like your elbow and knee move in one direction like a door swinging open and closed. Ball-and-socket joints like your shoulder and hip rotate in almost any direction so you can throw a ball or kick a soccer ball. Pivot joints like the one in your neck let you shake your head no. Gliding joints in your wrist and ankle let small bones slide past each other for fine movements. The type of joint controls what kind of motion is possible, which is why your knee can't rotate like your shoulder, and why your shoulder can't lock straight like your knee. Different jobs, different joint designs.
"Babies have fewer bones than adults because they're smaller"
Plot twist: babies actually have more bones than adults, not fewer. A newborn has around 270 bones. An adult has 206. The difference is fusion. As a child grows, certain bones in the skull, spine, and hips fuse together into single, stronger bones. The skull starts as separate plates that move during birth and slowly knit together over the first couple years of life. Same idea in the pelvis and the long bones, which have separate growth-plate regions that fuse together by the late teens. Babies have more pieces of bone. Adults have fewer, but they're bigger and bonded into one solid structure. That's also why teenagers grow so fast and need extra calcium. Their bones are still actively building.
"Bone marrow is just empty filling inside the bones"
Bone marrow is the opposite of empty filling. It's one of the busiest tissues in your entire body. Red marrow, found in flat bones like the sternum, ribs, hip bones, and the ends of long bones, produces red blood cells, white blood cells, and platelets. Every second, your body makes about two million new red blood cells in the marrow. Without it, you couldn't carry oxygen to your tissues, fight infection, or clot a cut. Yellow marrow, found in the long shaft of bones like the femur, stores fat as a chemical energy reserve the body can tap when needed. Marrow is the reason the skeletal system gets credit for blood cell production on its list of main functions. It's not filler. It's a factory.

What's included in the Skeletal System Functions 5E Lesson download

📷 Inside-the-product — add screenshot of Read It passage or sample answer sheet

When you buy the Skeletal System Functions Complete 5E Lesson, you get a single download with the whole unit:

✅ Engage materials — teacher directions, student observation sheet, answer key, four learning objective slides, illustrated Body Systems Word Wall (English + Spanish)
✅ The full Station Lab — 8 stations + 1 challenge, print and digital, two reading levels, Spanish Read It!
✅ Explain materials — editable Presentation at two differentiated levels (with built-in Brain Breaks, Quick Action INB tasks, and Think About It prompts), guided fill-in-the-blank student notes handout with answer key, Paper Interactive Notebook (English + Spanish), Digital Interactive Notebook at two levels with answer keys
✅ Elaborate (Student Choice Projects) — 6 project options + design-your-own, plus a Reinforcement version with vocabulary-focused alternatives, 5-category rubric included
✅ Summative assessment — full 12-question version and modified version with sentence-starter scaffolds, both with answer keys
✅ Sample unit plan — day-by-day pacing guide

A couple of real-talk tips from running this lesson

1. Bring in a real bone on Day 1.

If you can get hold of a clean chicken or turkey leg bone, snap it open in front of the class. The visible marrow inside changes the entire conversation about the skeleton being "alive." If you can't, even a quick video clip of marrow under a microscope works. The point is to make bone feel like a living organ, not a Halloween decoration.

2. Have kids build all four joint types, not just one.

It's tempting to have each group build one joint and share. Don't. Every kid needs to feel a hinge joint move differently from a ball-and-socket joint in their own hands. The five-minute time cost is worth the lightbulb moment when they realize why the elbow and shoulder don't move the same way.

3. Connect the skeleton to other systems early.

The whole point of TEKS 7.13A is the function AND interaction of body systems. Start dropping cross-system connections from Day 1: skeletal protects nervous, skeletal makes blood for circulatory, skeletal pairs with muscular for movement. By the time kids hit the last body system in the unit, they'll have the pattern wired in.

Get the Skeletal System Functions 5E Lesson

Buy the full Skeletal System Functions 5E Lesson — $13.20

Or if you only need the one-day hands-on Station Lab:

Buy the Skeletal System Functions Station Lab — $7.20

(The Station Lab is included in the full 5E Lesson)

Frequently asked questions

Does this cover all of TEKS 7.13A?

For the skeletal system, yes. The full standard asks students to describe the function and interactions of all 10 major body systems. This lesson covers the skeletal system in depth, including its five main functions and how it interacts with the muscular, circulatory, and nervous systems. We have nine more 5E lessons for the other body systems under the same standard.

What do my students need to know before this lesson?

A basic understanding of cells, tissues, and organs from earlier grade-level standards. If your kids can describe what an organ is and the difference between a cell and a tissue, they're ready.

How long does it take to teach?

Done with fidelity, about 10 class periods of 45 minutes each: one day for the Engage, two days for the Station Lab, two days for the Presentation and Interactive Notebook, three days for the Student Choice Project, and one to two days for review and the assessment. A compressed sample plan is included in the file if you need to move faster.

Do I need special supplies?

Just straws, brass fasteners (brads), and a small amount of clay or playdough for the Explore It! joint-modeling station, plus printed cards for the Engage. Most teachers already have what they need.

Does this work for digital classrooms?

Yes. Every component has a digital version. The Station Lab is fully digital-ready (Google Slides), the Presentation works in Google Slides, and the Student Choice Projects can be submitted as videos, slide decks, or written work.

Is this 5E lesson aligned to NGSS too?

It aligns with MS-LS1-3 (using arguments supported by evidence for how the body is a system of interacting subsystems composed of groups of cells). Built TEKS-first, but the standards overlap.