點解係cartilage 就可以防止 collapse?

cartilage 雖然可以稍微變形 [例如將鼻頭的軟骨按下去] 及回復原狀, 但唔可以 stretch, 因為佢冇彈性 [inelastic]. 彈性既物料例如橡筋, 氣球. cartilage 係唔可以像氣球一樣拉長, 回彈.

而trachea沒有cartilage 的部分只有肌肉, 呢d就有彈力, 好似一個氣球. 氣壓高就充氣, 脹大, 氣壓低就扁下來. cartilage 就似透明膠紙[膠紙座上拉出來的膠紙]. 可以改變形狀, 但不可拉長, 回彈, 即沒有彈性.

如果你有氣球和膠紙就可以試下呢個實驗: 將氣球吹脹一半左右, 用橡筋縛好, 上面貼d膠紙. [貼得唔好千期咪搣出來貼過, 好容易搣爆, 求其貼得啦]. 然後將氣放掉, 氣球既表面collapse了, 但貼住膠紙既地方依然維持一點stretched. 再將氣球吹脹, 脹過貼膠紙時, 氣球表面全stretch了, 只有貼住膠紙既地方皺皺地, stretch 唔到.

呢個就係氣管[氣球]內的軟骨[膠紙]的功能示範啦.希望幫到你了解軟骨既物理特性啦.

The larynx consists of hyaline cartilages: thyroid, cricoid, paired arytenoid, corniculate, and cuneiform; and the epiglottis, which is elastic cartilage. 因此可以 prevent 到 collapsing or stretching.

Trachea is flexible tube running from larynx. Walls contain C-shaped cartilages. 因此都可以 prevent from collapsing.

Although cartilage is also called 'soft bone' in chinese, it is not really soft. In fact, it is as hard as your finger nails, already enough to support your layrnx and trachea from collapsing.