Vertebral Column Notes

Vertebral Column Overview

• Functions: Protect spinal cord, support head, attachment site for muscles (back, upper limb, pelvic girdle, ribs).
• Flexible rod, strong, allows movement and rotation.

Adult Vertebrae Count

• Total: $26$ vertebrae (adult).
• Breakdown: $7$ cervical, $12$ thoracic, $5$ lumbar, $1$ sacrum, $1$ coccyx.
  • Mnemonic: $7, 12, 5$ (breakfast, lunch, dinner).

Spinal Curves

• Adult: $4$ curves (cervical, thoracic, lumbar, sacral).
• Infant (Born with): $2$ curves (thoracic, sacral) - primary curves.
• Secondary Curves: Develop after birth.
  • Cervical curve (when baby holds head up).
  • Lumbar curve (when able to stand/walk).
• Functions of curves: Balance, upright posture, increased column strength.

Intervertebral Discs

• Located between bony vertebrae.
• Composition: Outer rim of fibrocartilage (annulus fibrosus), inner pulpy substance (nucleus pulposus).
• Functions: Form joints, allow flexibility, cushion, contribute to height.
• Herniated/Slipped Disc: Rupture/protrusion of nucleus pulposus, pressing on spinal nerves.
  • Symptoms: Pain, tingling, numbness.
  • Most common in lumbar region due to bearing most body weight and frequent flexing/bending.
  • Treatment: Physical therapy (minor), surgery (severe).

General Vertebra Structure

• Body: Thick, weight-bearing part.
• Vertebral Foramen: Hole for spinal cord.
• Vertebral Arch: Formed by lamina and pedicles.
• Intervertebral Foramen: Openings for spinal nerves.
• Processes:
  • Spinous process: $1$, projects posteriorly, palpable along back.
  • Transverse processes: $2$, project laterally.
  • Facets: $2$ superior and $2$ inferior, covered with hyaline cartilage, articulate with adjacent vertebrae.

Types of Vertebrae

• Cervical Vertebrae (C1-C7):
  • Smallest (except coccyx).
  • Characteristic: $3$ holes (vertebral foramen and $2$ transverse foramina).
  • Some have bifid (split) spinous processes (e.g., C3-C6).
  • Atlas (C1): No body, no spinous process. Grooves for occipital condyles; allows