Lecture Notes: Spine Structure and Function

Overview

• Spine Structure: Comprised of cervical, thoracic, lumbar vertebrae
• Functions: Protects organs, absorbs shock, provides flexibility and strength
• Movements: Flexion, extension, rotation, lateral bending, retraction, protraction

Cervical Spine (C-Spine)

• Vertebrae: 7 cervical vertebrae (C1-C7)
• C1 (Atlas): No vertebral body, supports the head, allows flexion/extension
• C2 (Axis): Has dens, allows rotation, provides pivot for C1
• C7: Easily palpable, allows flexion, extension, rotation, bending of the neck

Thoracic Spine (T-Spine)

• Vertebrae: 12 thoracic vertebrae (T1-T12)
• Movement: Limited due to large spinous processes, forms joint spaces with ribs (costal facets)
• Stability: Less mobile, more stable, fewer injuries

Lumbar Spine (L-Spine)

• Vertebrae: 5 lumbar vertebrae (L1-L5)
• Movement: More mobile than T-spine, allows greater flexion/extension
• Common Injuries: Disc herniations/ruptures common at L4-L5, L5-S1
• L5: Forms joint with sacrum, more movement

Intervertebral Discs

• Function: Absorb shock, maintain spinal flexibility
• Composition: Makes up 25% of spinal column length
• Injuries: Susceptible to rupture/herniation (e.g., L4 herniated disc)

Ligaments

• Function: Protect spinal cord, strengthen spine
• Types: Connect transverse processes, spinous processes, anterior and posterior ligaments

Summary

• Curvature: Spine curvature provides 10x more strength, helps absorb shocks from head/feet
• Vertebrae Structure: Body, spinous process, transverse process, superior/inferior articular processes, intervertebral facet joints
• Thoracic Region: Facet joints with ribs
• Lumbar Region: Greater flexibility, common injury site
• Neck & Torso Movements: Flexion, extension, lateral bending, rotation, retraction, protraction

Next Topic

• Movements and Muscles: Detailed discussion on muscles producing neck and torso movements