_4,4_. The transverse processes.
_5,5_. The articular processes.
_6,6_. A portion of the bony bridge
which assists in forming the spinal
canal (7).]

[Illustration: Fig. 14.
Backbone, spinal
column, or vertebral
column. All
animals possessing
such a row of bones
are called _vertebrates_.
Above _b_ are
the cervical (neck)
vertebræ; _b_ to _c_,
dorsal (back) or
chest vertebræ; _c_
to _d_, lumbar (loins)
vertebræ; _d_ to _e_, sacrum;
_e_ to _f_, coccyx.]

The _Spinal Column_ or backbone, when viewed from the front presents a
perpendicular appearance, but a side view shows four distinct curves.
The bones composing it are called _vertebræ_. The body part of a
vertebra is light and spongy in texture, having seven projections called
_processes_, four of which are the _articular_ processes, which furnish
surfaces to join the different vertebræ of the spinal column. Two are
called _transverse_, and the remaining one is termed the _spinous_. The
transverse and spinous processes serve for the attachment of the muscles