Question

Which of the following is NOT true about the right principal (main) bronchus?

• A. Shorter
• B. Wider
• C. More horizontal
• D. In the line of trachea

Hint:

The right bronchus is wider, shorter and more vertical; horizontal describes the left.

Answer 1

The Correct Option is C

Step 1: The trachea bifurcates at the carina (lower border of T4, at the T4-T5 disc level) into the right and left principal bronchi. Their geometry differs, and this difference is clinically important for foreign body inhalation.

Step 2: The right principal bronchus is wider, shorter (about 2.5 cm), and more vertical, lying almost in the direct line of the trachea (about 25 degrees with the median plane). Because of this near-vertical course, an inhaled foreign body is most likely to lodge on the right side.

Step 3: The left principal bronchus is narrower, longer (about 5 cm), and more horizontal (about 45 degrees with the median plane). So the feature "more horizontal" describes the LEFT bronchus, not the right.

Step 4: Therefore the statement that is NOT true about the right bronchus is that it is "more horizontal." The right bronchus is more vertical. Options shorter, wider, and in the line of the trachea are all correct descriptions of the right bronchus.