The active units of the kidney are the:  

Painful or difficult urination is:  

The duodenum, jejunum, and ileum are part of the:  

The nerve that activates the diaphragm is the:  

A condition of having an undescended testis is termed:  

The membrane that covers the lungs is the:  

Air or gas in the pleural space is termed:  

The hepatic portal system carries blood from the digestive tract to the:  

Wavelike contractions of the digestive tract constitute:  

The inhalation of food into the lungs is termed: