A body cavity is a space inside the body. Body cavities can remain hollow, such as the nasal cavity, be filled with fluid, such as the pericardial cavity, or be filled with organs, such as the abdominal cavity.
There are two major body cavities: the ventral body cavity and the dorsal body cavity, shown below. These cavities house major body organs. There are also smaller body cavities, such as the oral cavity, the nasal cavity, the middle ear, and the orbits that house the eyeballs.
Figure 1: The body has two major cavities, and these cavities are divided into smaller cavities.