Brjósthryggsliðir

Brjósthryggsliðir, also known as thoracic vertebrae, are the bones that make up the chest section of the vertebral column. In humans, there are typically twelve thoracic vertebrae, numbered T1 through T12. These vertebrae are situated between the cervical vertebrae of the neck and the lumbar vertebrae of the lower back. Each thoracic vertebra shares some common features with other vertebrae but also possesses unique characteristics adapted to its location and function.

The primary role of the thoracic vertebrae is to provide structural support for the torso and to protect the spinal cord. They also serve as attachment points for the ribs, forming the thoracic cage. This cage is crucial for protecting vital organs like the heart and lungs and plays a significant role in respiration.

Thoracic vertebrae have several key anatomical components. They feature a vertebral body, which is the main weight-bearing portion. Extending posteriorly from the body are the laminae and pedicles, which form the vertebral arch. The arch encloses the vertebral foramen, through which the spinal cord passes. A prominent spinous process extends backward from the junction of the laminae, serving as an attachment site for muscles and ligaments. Transverse processes extend laterally from the sides of the arch.

A distinguishing feature of thoracic vertebrae is the presence of costal facets. These are smooth articular surfaces located on the vertebral bodies and transverse processes where the ribs articulate. The number and location of these facets vary slightly among the thoracic vertebrae, accommodating the curvature and attachment of the rib cage. The size of the vertebral bodies generally increases from superior to inferior along the thoracic spine, reflecting the increasing weight they bear.