Kehaõõnsused

Kehaõõnsused refer to the fluid-filled spaces within an organism that house and protect organs. In vertebrate anatomy, the primary 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 contains the brain, and the vertebral cavity, which encloses the spinal cord. The ventral cavity is situated on the anterior side and is separated by the diaphragm into the thoracic cavity and the abdominopelvic cavity. The thoracic cavity contains the heart and lungs, and is further subdivided into the pericardial cavity (housing the heart) and two pleural cavities (each containing a lung). The abdominopelvic cavity is divided into the abdominal cavity, which holds digestive organs like the stomach, intestines, liver, and pancreas, and the pelvic cavity, which contains reproductive organs, the bladder, and the rectum. These cavities provide crucial protection for vital organs against mechanical shock and allow for their expansion and movement. They also contain serous membranes, such as the pleura, pericardium, and peritoneum, which secrete serous fluid to lubricate the organs and reduce friction as they move. Invertebrates, body cavities can vary significantly, with some possessing a coelom, a true internal body cavity lined by mesoderm, while others have a pseudocoelom or lack a true coelom altogether. The organization and function of these cavities are fundamental to the structural integrity and physiological processes of organisms.