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.
Physiology of the nasal cavity. The nasal cavity functions to allow air to enter the respiratory system upon respiration. Structures within the cavity regulate the flow of air and particles it contains. The olfactory region of the nasal cavity regulates the sense of smell.