Microscopic view
Step 1
Choose an organ
Step 2
Explore it in 3D
- Cranium: Twenty-one bones fused at sutures into a box for the brain, plus the mandible hung below it
- Vertebral Column: Twenty-six bones stacked into four curves, carrying the spinal cord down a canal of their own making
- Thoracic Cage: Twelve pairs of ribs and their cartilages — armour that has to move with every breath
- Pelvis: Two hip bones and the sacrum: the ring that passes body weight from the spine into the legs
- Femur: The longest and strongest bone in the body, and the only one running obliquely inward from hip to knee
- Humerus: The arm's single bone — the radial nerve winds around its shaft in a groove of its own
- Mandible: The only mobile bone of the skull, swinging and gliding at the temporomandibular joint
- Clavicle: The strut holding the shoulder out from the trunk; the middle third is the most commonly fractured bone segment in the body
- Scapula: A flat triangle that floats on muscle against the back of the ribs, carrying the shoulder socket on its outer angle
- Sternum: Manubrium, body and xiphoid — the front tie-beam of the cage, and a reliable source of marrow
- Sacrum: Five vertebrae fused into one wedge, driven between the hip bones as the keystone of the pelvic ring
- Radius: The forearm's lateral bone, which rotates over the ulna to turn the palm; its distal end is the most fractured site in the upper limb
- Ulna: The forearm's medial bone, fixed while the radius turns around it; its upper end is the olecranon, the subcutaneous point of the elbow, with the ulnar nerve just behind it
- Patella: The largest sesamoid bone, embedded in the quadriceps tendon to hold it off the joint and lengthen its leverage
- Tibia: The weight-bearing bone of the leg; its whole front border lies directly under the skin
- Lateral Malleolus: The fibula's lower end, sitting lower and further back than the medial — the bone that fails in most ankle fractures
- Calcaneus: The heel bone: the largest of the tarsals, the lever the calf muscles pull on, and the tarsal bone most often fractured
Step 3
Keep learning
Compare organs
Skeleton vs. muscles
Function animation
Supports, protects, moves, and banks minerals
Clinical notes
Red flags
- A limb that is deformed, pulseless, cold or numb beyond the injury, or a wound over a fracture — vascular injury, compartment syndrome and open fracture are all surgical emergencies within hours.
- Back pain with saddle numbness, retention or incontinence, or bilateral leg weakness, is cauda equina compression and needs an MRI the same day.
- Bone pain that wakes the patient at night, with fever, weight loss or a known cancer, is infection or malignancy — not mechanical pain — until imaged.
- Osteoporosis
- Osteoarthritis
- Rheumatoid arthritis
- Fractured neck of femur
- Scaphoid fracture
- Disc herniation
- Scoliosis
- Osteomyelitis
Where it works