He functions of the urinary system include

1) ultrafiltration where glomerular filtrate is obtained

2) selective re-absorption in which water and other important nutrients are re-absorbed

3) tubular secretion in which creatinine and potassium are secreted

4) the urine formed goes through through the ureter to the urinary bladder to be finally excreted out through the urethra

Air enters through the nose (and sometimes the mouth), moves through the nasal cavity, the  pharynx, the  larynx, enters the  trachea, moves through the  bronchi  andbronchioles  till the alveoli.