Which of the following maintains the patency (openness) of the trachea?
A. surface tension of water
B. surfactant
C. cartilage rings
D. pseudostratified ciliated epithelium
Answer:C
Which of the following maintains the patency (openness) of the trachea?
A. surface tension of water B. surfactant C. cartilage rings D. pseudostratified ciliated epithelium