Question

Respiratory dead space 

A. Saturates inspired air with water vapour before it reaches the alveoli. 

B. Removes all particles from inspired air before it reaches the alveoli. 

C. Decreases when blood catecholamine levels rise. 

D. Decreases during a deep inspiration. 

E. Decreases during a cough.

Answer 1

A. True This prevents drying of the alveolar surface. 

B. False Particles less than about two microns can reach the alveoli. 

C. False Catecholamines relax airway muscle and constrict mucosal vessels. 

D. False Expansion of the lungs expands airways as well as alveoli. 

E. True This allows air to be expelled at high airway velocity.