Final answer:
The four body cavities are the ventral cavity and the dorsal cavity, each with specific positions on the body.
Step-by-step explanation:
The four body cavities are the ventral cavity and the dorsal cavity. The ventral cavity is located on the front side of the body and contains the thoracic cavity and the abdominopelvic cavity, which are further divided into sub-cavities. The dorsal cavity is located on the back side of the body and contains the cranial cavity (which houses the brain) and the spinal cavity (which contains the spinal cord).