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4.3 Bones of the Axial Skeleton

The axial skeleton forms the central core of the body — it includes the skull, spine, ribs, and sternum. Its main jobs are to protect vital organs (like the brain, heart, and lungs), provide support, and anchor muscles.

A skeleton with the skull, rib cage and vertebral column highlighted and labelled.
Image by Lady of Hats, Public Domain Modified: some labels removed

Bones of the Axial Skeleton

Skull

Skull with labels. See text below.
“Human skull side simplified” by Lady of Hats, Public Domain  Modified by Alkd  Further modifications: some labels removed

The skull protects the brain and forms the shape of the head and face. The bones you need to know are:

  • Frontal: Forehead: Front part of the skull
  • Parietal: Top and upper sides of the skull
  • Temporal: Lower sides of the skull near the ears
  • Nasal: Bridge of the nose
  • Zygomatic: Cheekbones
  • Maxilla: Upper jaw; holds the upper teeth
  • Mandible: Lower jaw; the only movable skull bone, helps with chewing
  • Occipital: Back and base of the skull; contains a hole for the spinal cord (foramen magnum)

The Rib Cage

The rib cage and sternum.
Image by OpenStax, CC BY 4.0  Modified: cropped and some labels removed

The rib cage protects the heart and lungs. It includes:

  • Sternum: Flat bone in the center of the chest (breastbone)
  • 12 pairs of Ribs:
    • 7 True Ribs: Attach directly to sternum (numbered 1 to 7)
    • 3 False Ribs: Attach indirectly via cartilage (numbered 8 to 10)
    • 2 Floating Ribs: Do not attach to sternum at all (numbered 11 and 12)
The three parts that make up the Vertebral Column or spine - Cervical, Thoracic and Lumbar Vertebrae
“Vertebral Column” by RWhitwam, CC BY-SA 4.0

The Vertebral Column (Spine)

The spine supports the body, protects the spinal cord, and allows movement. It has three main regions:

  • Cervical Vertebrae: 7 bones in the neck area (C1 to C7)
  • Thoracic Vertebrae: 12 bones in the upper/mid-back; ribs attach here (T1 to T12)
  • Lumbar Vertebrae: 5 large, strong bones in the lower back (L1  to L5)

Quick Tip:

  • “Breakfast at 7” = 7 Cervical Vertebrae
  • “Lunch at 12” = 12 Thoracic Vertebrae
  • “Dinner at 5” = 5 Lumbar Vertebrae

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The Foundations of Human Movement and Physical Fitness Copyright © 2025 by A.J. Stephen; Sarah Fraser; and Connor Dalton is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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