Normal Curvatures and Anatomy of the Spine

Spinal Curvatures Function

Absorb load and enhance spine flexibility.

Vertebral Body Size

Increases from cervical to lumbar for stress support.

Line of Gravity

Path through key spinal landmarks for balance.

Occipital Protuberance

Muscle and ligament attachment point on cranium.

Foramen Magnum

Passageway for spinal cord in the skull.

Occipital Condyles

Articulate with atlas (C1) for skull support.

Typical Vertebrae

Main structures include body and vertebral canal.

Intervertebral Discs

Cushioning shock absorbers between vertebrae.

Lordosis

Curvature in cervical and lumbar regions, supports head.

Kyphosis

Curvature in thoracic and sacrococcygeal regions, protects organs.

Nucleus Pulposus

Gel-like center of intervertebral discs.

Annulus Fibrosus

Tough outer layer of intervertebral discs.

Vertebral End Plate

Connects disc to vertebrae, provides nutrients.

Atlas (C1)

Supports skull, allows nodding motion.

Axis (C2)

Pivot for head rotation.

Cervical Vertebrae

C1-C7, small and mobile with unique features.

Thoracic Vertebrae

Longer spinous processes, limited extension due to ribs.

Lumbar Vertebrae

Massive bodies designed for weight-bearing.

Sacrum

Transmits weight to pelvis.

Coccyx

Tailbone located at spine's base.

Ligamentum Flavum

Limits flexion, attaches to laminae.

Supraspinous Ligament

Limits flexion, connects spinous processes.

Anterior Longitudinal Ligament

Limits extension, runs along anterior vertebral bodies.

Degrees of Freedom

Spine moves in three planes: flexion, lateral, rotation.

Coupled Motion

Side-bending often includes rotation in cervical spine.

Atlanto-Occipital Joint

Allows nodding motion (C0-C1).

Atlanto-Axial Joint

Responsible for 50% of head rotation (C1-C2).

Cervical Spine Mobility

Allows flexion, extension, side-bending, and rotation.

Craniocervical Region

Most mobile spine part, crucial for head movements.