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.
Earthworm. The earthworms' respiratory system is very different compared to other mammals, but the purpose is the same, get the oxygen and take out the carbon dioxide. Earthworms do not have lungs or gills like other mammals, but instead they breathe by using their moist skin.espiratory System. The respiratory system performs exchange between gases. The molecules of oxygen and carbon dioxide are exchanges, this process changes oxygen to carbon dioxide. Our respiratory system is responsible to clean out the bacteria or dust we breath in.