Structure of the Vertebra in the Spinal Column

General Overview of Vertebra

• Body (Centrum):
  • Central part of the vertebra.
  • Supports the majority of the weight.
• Vertebral Arch:
  • Consists of two components:
    • Pedicle: Forms outcropping, connected to lamina.
    • Lamina: Joins with pedicle to form arch.
  • Vertebral Foramen: Space for the spinal cord.
  • Intervertebral Foramina: Spaces for spinal nerve exit.

Processes on the Vertebra

• Spinous Process: Projects posteriorly.
• Transverse Processes: Projects laterally; attachment sites for muscles and ligaments.
• Articular Processes:
  • Superior and inferior processes protrude at pedicle-lamina junction.
  • Covered in hyaline cartilage, allowing joint movement between vertebrae.

Cervical Vertebra (C1-C7)

• General Characteristics:
  • Smallest vertebrae.
  • C1 (Atlas):
    • No body or spinous process.
    • Main components: posterior and anterior arches, lateral masses.
    • Articulates with occipital condyle, allowing "yes" head movement.
  • C2 (Axis):
    • Features dens fitting into atlas for "no" head movement.
• C3-C7 Features:
  • Oval-shaped body, bifid spinous process.
  • C7: Vertebra prominens, palpable.
  • Triangular vertebral foramen.
  • Transverse foramen for vertebral arteries.
• Types of Motion:
  • Flexion/extension, lateral flexion, rotation.

Thoracic Vertebra (T1-T12)

• Characteristics:
  • Progressively larger from T1-T12.
  • Spinous process points downwards, circular vertebral foramen.
  • Articular facets for rib articulation.
  • Limited flexion/extension, allows rotation and minimal lateral flexion.

Lumbar Vertebra

• Characteristics:
  • Largest, short and thick pedicles and lamina.
  • Hatchet-like spinous process.
  • Triangular vertebral foramen.
• Movement:
  • Capable of flexion, extension, and some lateral flexion.
  • No rotation due to structural stability needs.
• Articular Processes:
  • Nesting structure provides stability, prevents rotation.

Sacrum and Coccyx

• Sacrum:
  • Five fused vertebrae, forms posterior wall of pelvis.
  • Articulates with L5 and hip bones, forming sacroiliac joints.
• Coccyx:
  • Three to five fused vertebrae, articulates with sacrum.
  • Vestigial structure in humans.