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.
Air flow Sequence. The sequence in which incoming air flows through the upper respiratory tract is as follows: 1  Normally air enters the respiratory system through two external nares (openings of the nose) and proceeds through the nasal cavity and sinuses. 2  Air is warned, filtered, and moistened.ntroduction. The respiratory system consists of the nose, nasal cavity, pharynx, larynx, trachea, bronchial tree, and the lungs. Its primary function is the basic exchange of oxygen and carbon dioxide.