Bronchiole lumen diameters in respiratory anatomy

Steps:

• Recall that bronchioles are small airways branching from bronchi, with lumens less than 1 mm in diameter.
• Identify that terminal bronchioles represent the largest bronchioles before respiratory ones begin.
• Note standard histological measurements: terminal bronchioles have lumens up to 140 μm.
• Compare choices to this range to select the maximum value.

Why C is correct:

• Anatomical texts define the maximum bronchiole lumen diameter as 140 μm for terminal bronchioles, based on average human lung histology.

Why the others are wrong:

• A: 44 μm fits smaller respiratory bronchioles, not the maximum.
• B: 80 μm approximates diameters of even smaller alveolar ducts.
• D: 170 μm exceeds bronchiole sizes, aligning with larger bronchi.

Final answer: C