Eric Nielsen, age 9, of Asbury Park, N.J., for his question:

HOW MANY BONES ARE IN THE SPINAL COLUMN?  _

Vertebra is the name of any one of the bones that make up the spinal column. Two or more of the bones are called vetebrae.

A child has 33 vertebrae but an adult has only 26. The reason for this is because several of the vertebrae unite in a human's later life.

A vertebra has a central body with a pedicle, or bony extension, on each side. The pedicles join bilateral laminae to form an arch enclosing an opening called the vertebral foramen. The spinal cord passes through this opening.

A spinous process and two transverse processes extend from the arch. The transverse processes bear articular processes that connect with the articular processes of adjoining vertebra.