The vertebral column is extended from the back of the head till the posterior end of the body of the toad. It is also called the backbone. Vertebral column surrounds the spinal cord. The vertebral column of the toad is formed by nine ring-like bones called Vertebrae and a long bone called Urostyle. The structure of the first and ninth vertebra of the vertebral column is different. The structure of the second to eight vertebrae are almost alike.
Fig: the Vertebral column of Toad
Atlas: The first vertebra of the vertebral column is called the atlas. It is connected with the skull in front and the second vertebra (at the posterior). The Atlas looks like a ring. It has no transverse process, neural spine and prezygapophysis. Its neural canal is comparatively bigger in size. Atlas meets the next vertebra with the help of post zygapophysis.
Functions of vertebral column:
- The vertebral column by giving a definite shape forms to the frame of the body.
- It surrounds the spinal cord and protects it.
- Being attached to the pelvic girdle it assists in bearing the weight of the body and its movement.
- Being attached to the transverse process and neural arches of the muscles, vertebrate make the movement smoother.