Thoracic vertebrae

Thoracic Vertebrae

The thoracic vertebrae are a group of twelve vertebrae located in the middle section of the vertebral column, specifically between the cervical vertebrae and the lumbar vertebrae. These vertebrae are designated as T1 through T12, with T1 being closest to the cervical vertebrae and T12 being closest to the lumbar vertebrae. The thoracic vertebrae play a crucial role in supporting the upper body and protecting the spinal cord.

Diagram of a thoracic vertebra.

Anatomy

Each thoracic vertebra has a characteristic structure that distinguishes it from the cervical and lumbar vertebrae. The thoracic vertebrae are unique in that they articulate with the ribs, forming the posterior part of the rib cage.

Vertebral Body

The vertebral body of a thoracic vertebra is heart-shaped and larger than that of the cervical vertebrae but smaller than the lumbar vertebrae. The superior and inferior surfaces of the vertebral body are slightly concave.

Vertebral Arch

The vertebral arch consists of the pedicles and laminae, which enclose the vertebral foramen. The vertebral foramen is circular and smaller than that of the cervical vertebrae.

Spinous Process

The spinous process of thoracic vertebrae is long and projects downward, overlapping the vertebra below. This overlapping provides additional protection to the spinal cord.

Articular Processes

The superior and inferior articular processes of thoracic vertebrae are oriented in a coronal plane, allowing for rotation and some lateral flexion but limiting flexion and extension.

Costal Facets

Thoracic vertebrae have costal facets on the sides of the vertebral bodies and on the transverse processes for articulation with the ribs. The superior and inferior costal facets on the vertebral body articulate with the head of the rib, while the transverse costal facet articulates with the tubercle of the rib.

Function

The primary functions of the thoracic vertebrae include:

• Support: They support the weight of the upper body and provide attachment points for the ribs.
• Protection: They protect the spinal cord within the vertebral canal.
• Movement: They allow for limited movement, including rotation and lateral flexion, which is essential for activities such as breathing.

Clinical Significance

Thoracic vertebrae can be involved in various medical conditions, including:

• Scoliosis: A lateral curvature of the spine that can affect the thoracic region.
• Kyphosis: An excessive outward curvature of the spine, leading to a hunched back.
• Compression fractures: Often due to osteoporosis, these fractures can occur in the thoracic vertebrae, leading to pain and deformity.

Related Pages

• Cervical vertebrae
• Lumbar vertebrae
• Rib cage
• Spinal cord