Gas exchange occurs in the:

Which one of the following structures is NOT part of the respiratory zone:

B cells develop immunocompetence in the:

The serous membrane covering the surface of the lungs is called the:

The lymph organ that programs T cells and functions at peak levels only during youth is the:

The lipid molecule critical to lung function that coats the gas-exposed alveolar surfaces is called:

The respiratory movement representing the total amount of exchangeable air is the:

Tension on the vocal cords is regulated by

Following the removal of the larynx, a person would be unable to:

When oxygen enters the respiratory system, what is the next structure to which it travels immediately upon leaving the trachea: