Vertebral Anatomy and Physiology Quiz

Vertebral Anatomy and Physiology

• The vertebral column forms the musculoskeletal axis of the back, connecting the skull and pelvis.
• Thirty-three vertebrae are present: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), and 4 coccygeal (fused).
• Joints facilitate movement between bones.
• Muscles enable movement at joints; shoulder and hip joints are the most mobile due to ball-and-socket structure.
• Vertebrae increase in size caudally due to weight-bearing requirements.
• Vertebral curvatures (primary and secondary) contribute to posture and flexibility.
  • Primary curvatures (thoracic and sacral) are present at birth and are concave anteriorly.
  • Secondary curvatures (cervical and lumbar) develop later, are convex anteriorly, and are important for maintaining balance and posture.
• Spinous processes are located posteriorly; the vertebral body is situated anteriorly.
• Intervertebral disk protrusions can be alleviated with procedures like laminectomy.
• The vertebral foramen protects the spinal cord, which lies inside.
• The lamina is between the transverse and spinous processes; the pedicle connects the body to the transverse process.
• Superior and inferior articular processes form facet joints (zygapophyseal joints).

Cervical Vertebrae (C1-C7)

• Cervical vertebrae are smaller and have a larger vertebral foramen than other regions.
• C1 (atlas) lacks a vertebral body; its unique ring-like structure supports the cranium.
• C2 (axis) has an odontoid process (dens) for rotational movement of the head.
• The atlantoaxial joint allows for rotation (e.g., "no" movement).
• Vertebral arteries and veins pass through foramen transversarium, supplying the brain.

Thoracic Vertebrae (T1-T12)

• Thoracic vertebrae have a heart shape.
• Coastal facets articulate with ribs.
• The vertebral foramen is smaller compared to lumbar and cervical vertebrae.

Lumbar Vertebrae (L1-L5)

• Lumbar vertebrae have a massive vertebral body for weight-bearing.
• Mammillary and accessory processes provide attachment points for deep back muscles.

Sacral Vertebrae (S1-S5)

• Five sacral vertebrae fuse to form the sacrum.
• The sacrum displays various crests (median, intermediate, lateral) formed by the fusion of spinous, transverse, and articular processes.
• Sacral foramina allow for the passage of sacral nerves.
• Sacral cornua are important for caudal anesthesia.

Intervertebral Disks

• Intervertebral disks (symphyses) are present between all vertebrae except C1-C2, the skull, and the coccyx.
• Annulus fibrosus (fibrocartilage) and nucleus pulposus (gelatinous center) make up the disk structure.
• IV disk herniation (protrusion of the nucleus pulposus) can cause pain.
• There are 23 intervertebral disks in total

Ligaments

• Ligaments function to limit and control joint movements and protect joints.
• The transverse ligament holds the dens in place against the atlas; its rupture is damaging.

Venous Drainage of the Spine

• Batson's plexus is a network of veins within the vertebral canal, important for drainage.
• Batson's plexus lacks valves; tumor spreading is possible.

Muscles of the Back

• Intrinsic muscles act directly on the vertebral column; extrinsic muscles do not.
• Specific muscles and their actions (e.g., trapezius, rhomboids, latissimus dorsi) and their innervation by nerve pathways are important.
• Fiber direction determines muscle action.
• Muscle actions (e.g., retraction, depression, rotation of scapula) and the nerves responsible, are important to know

Spinal Injuries and Conditions

• Various spinal injuries (herniations, dislocations, compression) and their consequences (pain, weakness, paralysis) are relevant.
• Specific conditions like scoliosis, hyperlordosis, kyphosis, and spinal bifida occulta, with their characteristic features are important to know.
• Specific locations and neurological involvement in injuries are key.

Additional Notes

• The ligamentum flavum is a key location for lumbar puncture procedures.
• Understanding the different types of vertebral curvatures (lordosis, kyphosis) and how they relate to posture and movement.
• Knowledge of spondylolysis, spondylolisthesis, and spondylitis (and their characteristics and potential effects) and the associated pathologies (herniation, injury, etc).
• The relationship between various nerves and muscles, and potential impacts of injuries (on the muscles and resulting motor impairments)
• Important landmarks and how they relate to the spine (iliac crest, etc.)