Question

Rings of .................... present in trachea, bronchi and bronchioles prevent their collapse when air is not passing through them.

• A. Cartilage
• B. Collagen
• C. Bone
• D. None of the above.

Answer 1

The correct option is A Cartilage

In humans, trachea is a straight tube extending up to the mid-thoracic cavity, which divides at the level of 5th thoracic vertebra into a right and left primary bronchi. Each bronchi undergoes repeated divisions to form the secondary and tertiary bronchi and bronchioles ending up in very thin terminal bronchioles. The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings.