Respiratory arrest is the cessation of the normal tidal flow of the lungs due to paralysis of the diaphragm, collapse of the lung or any number of respiratory failures. It is a medical emergency and it usually is related to or coincides with a cardiac arrest. Respiratory arrest is first treated with Artificial respiration until the patient is revived or advanced life care arrives. The heart with relation to the lungs (from an older edition of Grays Anatomy) This x-ray of the human chest shows the lungs as dark regions The lung is an organ belonging to the respiratory system and interfacing to the circulatory system of air-breathing vertebrates. ... A diagram of the thoracic muscles featuring the diaphragm In the anatomy of mammals, the diaphragm is a shelf of muscle extending across the bottom of the ribcage. ... A medical emergency is an injury or illness that poses an immediate threat to a persons health or life which requires help from a doctor or hospital. ... Artificial respiration is a technique for providing air for a person who is not breathing on their own but whose heart is still beating. ...