In the majority of cases, incontinence is caused by a weakening of the pelvic floor muscles that keep the urethra closed. Whenever they lose their elasticity, everyday activities such as laughing, coughing, lifting and running can cause a urine leak.
The respiratory system consists of a group of ducts that are capable of filtering air from the environment before entering the pulmonary system.
respiratory zone (lower respiratory tracts): the actual site of gas exchange in the lungs, is composed of the terminal respiratory passageways that contain alveoli-namely, the respiratory bronchioles, alveolar ducts, and alveolar sacs.