The spinal cord begins at the occipital bone and extends down to the space between the first and second lumbar vertebrae; it does not extend the entire length of the vertebral column.
Earthworms are invertebrates, lacking a skeleton. To support and shape the body, they are filled with coelomic fluid. Earthworms sometimes appear to have a belt or saddle around their bodies; this is a clitelum, a structure containing maturing eggs.
An earthworm also has the same type nervous system as a human, just like a pig. As for the circulatory system, a humanâs pumps blood to and from the body and lungs with the help of the heart, blood vessels, and arteries. A pig, however, has a heart, blood, blood vessels, lungs, and a circulatory mechanism.