Cartilage Support in Respiratory Structures

Steps:

• Trachea contains C-shaped cartilage rings to maintain openness during breathing.
• Bronchi, as extensions of the trachea, have cartilage plates providing similar structural support.
• Bronchioles lack cartilage, using elastic fibers and smooth muscle for flexibility and control.
• Compare options: only C matches with cartilage in bronchus and trachea, absent in bronchiole.

Why C is correct:

• In the respiratory system, cartilage reinforces larger airways like trachea and bronchi to prevent collapse under pressure changes, per anatomical definitions.

Why the others are wrong:

• A incorrectly denies cartilage in bronchus, which requires it for rigidity.
• B wrongly includes cartilage in bronchiole and excludes it from trachea.
• D falsely removes cartilage from trachea, essential for its patency.

Final answer: C