Which of the following statements about the terminal bronchioles is true?

a. They are generally five divisions below the segmental bronchi.
b. They are the smallest of the purely con-ducting airways.
c. They average 3 to 4 mm in diameter.
d. They have well-defined and predictable amounts of cartilage.

ANS: B
Terminal bronchioles are the smallest conducting airways and function to supply gas to the res-piratory zone of the lung.