Cartlage
It is commonly called the Windpipe; the medical name is trachea.
When you breath in ( inhale) the air enters the lungs through the Bronchi/Bronchus which divides up into smaller airways called BRONCHIOLES, the bronchioles send air into the inside walls of the lungs where the alveolia allow oxygen to be absorbed by the blood cells and oxygenate the blood transfer throughout the body so basically the bronchiles send air into the inside walls of the lungs to allow the alveolia to absorb oxygen and transfer it throughout the body, the alveolus/alveolia is a air sac that holds the oxygen.
DNA
a structure is something that holds up
Centromeres.
The cell membrane holds a cell together.
As relapsing polychondritis advances, it causes more dangerous symptoms such as deterioration of the cartilage that holds the windpipe open.
Yes a Retainer wall is a structure, that holds back earth.
HISTONE PROTEINS
The cell wall
Chromozome
DNA