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.
Functions of the Respiratory Portion. The respiratory portion consists of respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli. It is hard to investigate the organisation of these structures in sections, because when the lungs are removed, they collapse.