• In your neck there are seven cervical vertebrae
• Supporting your chest there are 12 thoracic vertebrae
• Next are five lumbar vertebrae
• Below them is the sacrum (which consists of 5 sacral vertebrae)
• At the bottom, literally, comes the coccyx or "vestigial tail" which consists of four tiny vertebrae

Because they vary in size your vertebrae are all different, but there are some important similarities between the majority of them. At the front of each one there is a solid block of bone called the "body" of the vertebra.
The more complicated part of the vertebral bone is at the back and is called the "neural arch". This has a hole in the middle of it through which the spinal cord runs, and has a number of bits sticking out of it:

• Two 'Transverse Processes' stick out from the sides of each neural arch
• A 'Superior Articular Process' points upwards
• An 'Inferior Articular Process' points downwards
• And from the back of each neural arch the 'Spinous Process' sticks out (these are the bony bits you can feel if your run your fingers up and down your spine).

Further information can be found at:

Vertebrae, spine, numbering system, back pain