Vertebral column 1: introduction and typical features

• To provide internal support for the body
• Provide protection for the spinal cord that runs along its length
• Support and protection of local structures
• Provides large surface area for muscle attachment
• Needed for transfer of propulsive forces generated by the hind limbs during locomotion

Vertebrae

Axial

Irregular bones

compact, cancellous/spongy

vertebral body

• Cranial endplate - convex
• Caudal endplate - concave

The intervertebral disc space - it is occupied by a soft tissue structure called the intervertebral disc

The vertebral arch

• Right and left pedicles - wall
• Right and left laminae - roof

The vertebral foramen

The vertebral canal

Cranial and caudal notches.  There are a total of 4 notches per vertebra.

The spaces formed between cranial and caudal notches of adjacent vertebrae when the vertebrae align.

Spinal nerves and blood vessels

• They are located at the junction between the pedicle and lamina at the cranial and caudal aspects of the vertebra.  These allow each vertebra to articulate with the vertebrae cranial and caudal to it.
• There are a total of 4 on each vertebra

Synovial joints

• The dorsal spinous process
• Its function is to increase the surface area for muscle and ligament attachment

Two

Paraxial mesoderm

The sclerotome

Four

3

When the cranial and caudal parts of the sclerotomes fail to separate properly.  This results in two adjacent vertebrae fused together with no intervertebral disc space of articulations.

Vertebrae located at the boundary between different regions of the vertebral column that are confused as to which region they belong to e.g. 1st lumbar vertebrae with a rib or last thoracic vertebrae without one

When the vertebral body fails to form properly; instead of being its normal cylindrical shape the vertebral body is triangular instead.  This is why they are sometimes called wedge or butterfly vertebrae.  This can cause deviation of the vertebral column.