Vertebral Column

Overview

The vertebral column, also known as the spine, is a central structure in the human skeleton that provides support, protection for the spinal cord, and flexibility for movement. It is composed of individual vertebrae, which vary in structure depending on their location (cervical, thoracic, lumbar, sacral, coccygeal).

• Body: The thick, disc-shaped anterior portion of the vertebra that bears weight.

• Spinous Process: The posterior projection that can be felt through the skin; serves as an attachment point for muscles and ligaments.

• Pedicle: The short, thick processes that project posteriorly from the vertebral body, forming the sides of the vertebral arch.

• Lamina: The flattened or arched part of the vertebral arch, forming the roof of the spinal canal.

• Vertebral Foramen: The opening formed by the vertebral arch and body, through which the spinal cord passes.

• Superior and Inferior Facets (Articular Processes): Projections that articulate with adjacent vertebrae, allowing for movement and stability.

• Transverse Foramen (Cervical Only): Openings in the transverse processes of cervical vertebrae (C1–C7) for the passage of the vertebral artery and vein.

• Anterior and Posterior Arches (Atlas/C1 Only): Unique to the atlas (C1), which supports the skull and allows nodding movements.

• Odontoid Process (Dens, Axis/C2 Only): A peg-like projection from the axis (C2) that allows rotation of the head.

Example: The atlas (C1) lacks a vertebral body and spinous process, while the axis (C2) features the dens for head rotation.

Sternum

Overview

The sternum, or breastbone, is a flat bone located in the center of the chest. It connects to the ribs via costal cartilages and forms the anterior portion of the rib cage, protecting vital organs such as the heart and lungs.

• Manubrium: The broad, upper part of the sternum that articulates with the clavicles and first pair of ribs.

• Body: The elongated central portion, which connects to the costal cartilages of ribs 2–7.

• Xiphoid Process: The small, cartilaginous lower tip of the sternum, which ossifies with age.

• Costal Cartilage: Bars of hyaline cartilage that connect the ribs to the sternum, allowing for flexibility and expansion during breathing.

Example: The manubrium is palpable at the base of the neck and serves as an important landmark for clinical procedures.

Ribs

Overview

Ribs are curved bones that form the majority of the thoracic cage, protecting the lungs and heart. They articulate posteriorly with the vertebral column and anteriorly with the sternum (via costal cartilage).

• Head: The end of the rib that articulates with the vertebral bodies.

• Tubercle: A small bump near the head that articulates with the transverse process of the vertebra.

• Body/Shaft: The long, curved portion of the rib.

Example: True ribs (1–7) attach directly to the sternum via costal cartilage, while false ribs (8–12) do not.

Table: Comparison of Vertebral Structures

Additional info: Table entries inferred from standard anatomical features of vertebrae.