Stratospheric ozone has declined for several years now at increasing rates. CFC molecules strip oxygen atoms from thousands of molecules of ozone. During embryonic development, a large central cavity, called a coelom, develops into the thoracic and abdominal cavities. The dorsal cavity contains the cranial cavity and vertebral column. Examples include the pleural membranes and the peritoneum.
Synovial membranes line joint cavities and secrete a lubricating synovial fluid.
Meninges are membranes within the dorsal cavity and are composed only of connective tissue. They protect the brain and spinal cord. The skin is called the integumentary system because it is comprised of a number of organs. The skeletal and muscular systems support the body and allow movement. The nervous system and endocrine system regulate and coordinate the activities of the various body systems.