Anatomy of the Vertebral Column

Introduction

• Presented by Peter from Anatomy Zone.
• Interactive annotated 3D models available on the website.

Overview of the Vertebral Column

• Part of the axial skeleton.
• Functions:
  • Supports body weight.
  • Encloses and protects the spinal cord in the spinal canal.
  • Provides framework for attachment of muscles.

Types of Muscles Related to the Vertebral Column

• Extrinsic back muscles:
  • Involved in moving upper limbs and ribcage.
• Intrinsic back muscles:
  • Important for maintaining posture and moving the vertebral column.

Structure of the Vertebral Column

• Composed of:
  • 24 articulating vertebrae:
    • 7 cervical (C1-C7)
    • 12 thoracic (T1-T12)
    • 5 lumbar (L1-L5)
  • Sacrum and coccyx:
    • 9 fused vertebrae.

Intervertebral Discs

• Located between vertebrae, acting as shock absorbers.
• Structure:
  • Annulus fibrosis: Tough outer layer.
  • Nucleus pulposus: Gelatinous center.
• Issues:
  • Herniation occurs due to degeneration or trauma, affecting spinal cord or nerve roots.

Naming Convention of the Vertebrae

• Cervical: C1-C7
• Thoracic: T1-T12
• Lumbar: L1-L5
• Spinal nerves exit according to vertebral levels:
  • 8 cervical nerves for 7 cervical vertebrae (C1 exits above C1).

Example of Spinal Nerve Exit

• Lumbar Region: L3 spinal nerve exits between L3 and L4 vertebrae.

Clinical Relevance

• Lumbar Puncture:
  • Spinal cord terminates at L1-L2.
  • Identify L4 level via iliac crests for safe needle entry.
• Anatomical Landmarks:
  • Angle of Louis at T4-T5, dividing mediastinum.

Curvatures of the Vertebral Column

• Adult Curvatures:
  • Cervical lordosis: Anterior convexity.
  • Thoracic kyphosis: Dorsal convexity.
  • Lumbar lordosis: Anterior convexity.
  • Pelvic curvature: Concave anteriorly.
• Neonate: One fixed kyphotic curvature (primary curvature).

Movements of the Vertebral Column

• Possible movements:
  • Flexion
  • Extension
  • Rotation
  • Lateral flexion
• Movements limited by:
  • Joint morphology.
  • Ribs in the thoracic region.
  • Ligamentous structures.

Specialized Joints in the Cervical Spine

• Atlanto-occipital Joint:
  • Between skull and C1 (Atlas).
  • Allows flexion, extension, and slight lateral flexion.
• Atlanto-axial Joint:
  • Between C1 (Atlas) and C2 (Axis).
  • Pivot joint enabling rotation.

Conclusion

• Recap of the vertebral column anatomy.
• Encouragement to check out the 3D model on the website.