What is the significance of the fact that the human trachea is reinforced with cartilage rings?

Answer 1

Through evolution, fish changed and made gills into other structures. This is the last one of the gills (others made our jaw bone and ear, for example). These rings "used" to be a gill. (If you look at pictures of the development of a baby in the uterus you can see gills form and then get developed into other structures.)

Answer 2

The trachea is reinforced with cartilage rings because they provide extra support and prevent it from collapsing.

Answer 3

It enables the free movement of the throat as one turns or raises and/or lowers one's head...