Question

Inspiratory stridor is found in what kind of lesions?

• A. Supraglottic
• B. Subglottic
• C. Tracheal
• D. Bronchus

Hint:

Inspiratory equals above the glottis; expiratory equals lower trachea.

Answer 1

The Correct Option is A

Step 1: Stridor is a harsh sound produced by turbulent airflow through a partially obstructed airway. The phase of the respiratory cycle in which it occurs tells you where the obstruction is.
Step 2: An inspiratory stridor points to obstruction ABOVE the level of the glottis, that is at the supraglottic region. During inspiration the negative airway pressure tends to collapse the lax supraglottic structures, making the noise loudest in this phase.
Step 3: By contrast, an expiratory stridor indicates obstruction in the lower trachea or bronchi, and a biphasic (both phases) stridor suggests a fixed glottic or subglottic lesion. This is why subglottic, tracheal and bronchial options are not the best fit for a purely inspiratory stridor.
Step 4: Therefore inspiratory stridor localises to a supraglottic lesion, making option (a) the correct answer.