Which type of bones are characterized by irregular size and shape and include the vertebral column?

Irregular bones are defined by their complex shapes and varying sizes, which do not fit into the other categories of bones like long, flat, or sesamoid bones. The vertebral column is a prime example of irregular bones, as each vertebra has a unique structure that contributes to the overall flexibility and support of the spine. These bones are essential for protecting the spinal cord while allowing for a range of motion and stability. The irregularity in their shape accommodates the various functions that these bones fulfill in the skeletal system. By having diverse structures, irregular bones provide an important framework within the body, specifically where protection and support are necessary, such as in the case of the vertebrae.