The skeletal system comprises 206 bones and has two main parts: the axial skeleton and the appendicular skeleton.
Bones fall into two main categories.
Axial Skeleton
Theaxial skeletonforms the “axis” that runs down the center of the body.
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There are 80 bones that make up the axial skeleton.
Skull (Cranium)
Your skull (cranium) is made up of cranial and facial bones.
Cranial bones protect your brain, while facial bones make up your facial structure.
Skull bones include the following.
They are located in the inner ear and are structures that help create sound in your body.
It is part of bodily functions like speaking, swallowing, and airway maintenance.
The thoracic cage comprises 12 pairs of ribs connecting to the thoracic vertebrae and the sternum.
Your rib cage protects your heart.
Upper Extremities
Your upper extremities refer to your shoulders and arms.
With osteoporosis, the most commonly fractured bones are the vertebrae in the spine.
Imaging Tests
Healthcare providers use various imaging tools to get detailed pictures of your bones.
The appendicular skeleton includes your arms and legs.
Different injuries and diseases can affect the skeletal system.
Imaging procedures, blood or biopsy tests, and bone density tests can help to diagnose these conditions.
National Cancer Institute SEER Training Modules.Axial skeleton (80 bones).
2016;12(2):146-157. doi:10.1007/s12024-016-9769-x
Osmosis from Elsevier.Bones of the vertebral column.
National Cancer Institute SEER Training Modules.Appendicular skeleton (126 bones).
American Academy of Orthopaedic Surgeons.Osteoporosis and spinal fractures.
National Cancer Institute SEER Training Modules.Introduction to the skeletal system.
National Institute of Arthritis and Musculoskeletal and Skin Diseases.Muscle and bone diseases.
Institute for Quality and Efficiency in Health Care.Understanding tests used to detect bone problems.
Johns Hopkins Medicine.Joint aspiration.
