Question

Which of the following structures are supported by incomplete cartilagenous rings?
$a$. Tracheae
$b$. $1^{\circ}$ bronchi
$c$. $2^{\circ}$ bronchi
$d$. $3^{\circ}$ bronchi
$e$. initial bronchioles
$f$. terminal bronchioles
$g$. duct of alveoli
$h$. alveoli

• A. $a, b, c, d$ and $e$
• B. $a, b, c, d, e$ and $f$
• C. $a, b , c , d , e , f$ and $g$
• D. $a, b, c, d, e, f, g$ and $h$

Answer 1

Answer: (A)

The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings
• Trachea is supported by C-shaped cartilagenous rings made of hyaline cartilage
• The cartilagenous rings are incomplete posteriorly and prevent collapsing the wall of trachea