If a patient is choking and cannot speak or breathe, what should be done?

Under normal circumstances, carbon dioxide is excreted from the body by what structure?

a. The kidney b. The urinary tract c. The lungs d. The hepatic vein

The upper chambers of the heart are separated by the:

A) interventricular septum B) interatrial septum C) atrioventricular groove D) mediastinum