Skeletal System
Explore the bones, joints, and connective tissues that support the body, protect its organs, and work with muscles to make movement possible.
Explore the skeletal system
Use the interactive skeletal guide to explore the skull, spine, ribcage, and the bones of the limbs.
Open Innerbody guide →Explore the full skeleton
Rotate and inspect a complete 3D model of the human skeleton, from the skull to the feet.
Open model source →Learn it step by step.
Start with the complete skeleton, then move into the axial and appendicular divisions, how joints permit movement, and how bone itself grows and remodels.
The Skeletal System
Build the foundation. Learn the functions of the skeleton, how bones are classified, and the difference between the axial and appendicular divisions.
Axial Skeleton
Explore the skull, vertebral column, and thoracic cage that form the body's central axis.
Appendicular Skeleton
Learn the shoulder girdle, arms, pelvic girdle, and legs that make up the body's limbs.
Joints & Movement
Discover the types of joints in the body and how their structure determines their range of motion.
Bone Tissue & Growth
Zoom down to the cellular level and learn how bone tissue forms, grows, and continually remodels itself.
Test Your Knowledge
Finished all five lessons? Take the final Skeletal System assessment and see how much you remember.
From frame to cell.
The easiest way to understand the skeleton is to move from the whole frame down to the tissue: skeleton → axial and appendicular divisions → joints → bone cells.
The whole skeleton
Learn the functions of the skeleton and how its 206 bones are organized into two divisions.
Axial and appendicular
See how the axial skeleton protects organs while the appendicular skeleton enables movement.
Joints and bone cells
Understand how joints connect bones and how living bone tissue grows and repairs itself.