Assertion: trachea's ring | /r/MadeOf | cartilage
Facets:
Source sentences:
text: The trachea is stabilized and kept open by rings made of cartilage that surround the front and sides of the structure; these rings are not closed and do not surround the back, which is made of membrane.
text: A healthy trachea is supported by a series of C-shaped rings made of cartilage that help your child’s airway to stay open during exhalation.
text: It maintains its shape because of a series of rings made of cartilage.