In childhood, there are 32 or 33 vertebrae, divided into 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 sacral vertebrae, and 3-4 coccygeal vertebrae.

In adulthood, 5 sacral vertebrae merge to form the sacrum, and 3-4 coccygeal vertebrae fuse to form the coccyx.

The vertebrae are composed of the vertebral body in front and the vertebral arch in the back.

The vertebral body and vertebral arch form a vertebral foramen, so the vertebral foramina of the vertebrae are connected to form the spinal canal, which houses the spinal cord.

The part where the vertebral body connects with the vertebral arch is the vertebral pedicle. There are notches above and below each, called the "supraspinal notch" and "infravertebral notch". The upper and lower notches of adjacent vertebrae form the intervertebral foramen. , spinal nerves and blood vessels pass through the hole.

The pedicle of the vertebral column expands and widens posteriorly and medially, and is called the lamina. There is a spinous process, a pair of transverse processes, a pair of superior articular processes, and a pair of inferior articular processes on the vertebral arch.

The vertebral bodies are small and oval in cross-section.

transverse process foramen

The 1st cervical vertebra (atlas) has no spinous process, the 2nd-6th cervical vertebra have shorter spinous processes with bifurcated ends, and the 7th cervical vertebra has a longer spinous process.

The vertebral body gradually increases from top to bottom, and the cross-section is heart-shaped.

The back part of the vertebral body and the end of the transverse process have articular surfaces connected to the ribs, called costal recesses. The upper and lower costal recesses of the vertebral body and the transverse process costal recesses are the most important and prominent features of the thoracic vertebrae.

The spinous processes of the thoracic vertebrae are long, tilted backward and downward, and arranged in an imbricated manner.

The vertebral bodies are thick and heart-shaped in cross-section.

Lumbar vertebrae have no costal recesses and no transverse process foramen

The spinous process is a rectangular bone plate, which is in the sagittal position and extends horizontally to the rear. The gap between adjacent spinous processes is large, and lumbar puncture can be performed clinically here.

Definition: It refers to the longitudinal tube of the sacrum called the sacral canal. The sacral canal opens downward into the sacral canal hiatus. The downward protrusions on both sides of the sacral canal hiatus are called sacral angles. They are the positioning landmarks of clinical sacral canal anesthesia.

Features

It is formed by the fusion of 3-4 tail vertebrae