Kehaõõntidesse

Kehaõõntidesse, or body cavities, are fluid-filled spaces within the bodies of multicellular animals that house and support internal organs. These cavities play a crucial role in protecting organs from mechanical shock, allowing for organ movement and expansion, and facilitating the exchange of substances.

In vertebrates, the two main body cavities are the dorsal cavity and the ventral cavity. The dorsal cavity is located on the posterior side of the body and is further divided into the cranial cavity, which encloses the brain, and the vertebral cavity, which contains the spinal cord.

The ventral cavity is located on the anterior side and is the larger of the two. It is subdivided by the diaphragm into the thoracic cavity and the abdominopelvic cavity. The thoracic cavity houses the heart and lungs, while the abdominopelvic cavity contains the digestive organs, urinary organs, and reproductive organs.

In invertebrates, body cavities vary greatly in structure and function. Some, like coeloms, are true body cavities lined with mesoderm. Others, such as pseudocoeloms, are only partially lined with mesoderm. Animals without a true body cavity are called acoelomates. The presence and type of body cavity are important characteristics used in animal classification.