Thoracic Vertebrae

The thoracic vertebrae are a group of 12 vertebrae (T1–T12) situated in the mid-back region between the cervical and lumbar spine. They form the thoracic segment of the vertebral column and are uniquely adapted to articulate with the ribs, contributing to the structural framework of the thoracic cage. These vertebrae exhibit features that reflect their load-bearing and protective functions.

Structure

Each thoracic vertebra has a characteristic structure that distinguishes it from cervical and lumbar vertebrae. They are medium-sized and progressively increase in size from T1 to T12. Common structural features include:

General Features

• Vertebral body: Heart-shaped and larger than cervical vertebrae
• Vertebral foramen: Circular and smaller than in cervical vertebrae
• Spinous process: Long and angled sharply downward (especially in mid-thoracic levels)
• Transverse processes: Have costal facets for articulation with rib tubercles
• Articular facets: Oriented in the coronal plane; superior facets face posteriorly, inferior facets face anteriorly
• Costal facets (demifacets): On the sides of the vertebral bodies for articulation with rib heads

Notable Variations

• T1: Resembles cervical vertebra; has a complete costal facet for the 1st rib
• T10–T12: Resemble lumbar vertebrae; T11 and T12 have single complete costal facets and no transverse costal facets

Location

The thoracic vertebrae are located in the posterior thoracic region, forming the central part of the vertebral column. They span from the base of the neck to the lower back and are aligned vertically between the cervical (C7) and lumbar (L1) vertebrae.

Function

• Structural support: Supports the weight of the upper body and transfers it to the lower regions
• Rib articulation: Each vertebra articulates with ribs, forming the posterior part of the thoracic cage
• Protection: Encloses and protects the spinal cord within the vertebral canal
• Movement limitation: Orientation of articular facets limits flexion and extension, allowing primarily rotational movement

Clinical Significance

• Compression fractures: Common in osteoporosis, especially in the mid-thoracic region
• Kyphosis: Excessive anterior curvature involving thoracic vertebrae
• Costovertebral joint dysfunction: Can contribute to thoracic back pain and restricted respiration