The adult human trachea is about ________ in diameter and contains ________ tracheal cartilages.
A) 1.0 cm; 15-20
B) 1.0 cm; 10-15
C) 2.5 cm; 15-20
D) 2.5 cm; 40-50
E) 4.5 cm; 60-80
Question 2
Control of the diameter of the respiratory passages depends upon
A) sympathetic stimulation only.
B) parasympathetic stimulation only.
C) somatomotor stimulation only.
D) both parasympathetic and sympathetic levels of stimulation.
E) sensory receptors sensitive to changes in lung ventilation.