Trachea and Bronchi?

The trachea is the windpipe. It is a tube that must remain open or patent so air can freely flow, and at the same time allow a clump or bolus of swallowed food to p down the esophagus. The esophagus lies directly behind or posterior to the trachea. The structure of the trachea allows for both functions. The trachea is held open by hyline cartilage rings, these rings are "C" shaped with the opening of the C facing posterior in front of the the esophagus. The opening of the C on the posterior side allows that bolus of food to push into the trachea on its way down to the stomach. I want to clarify the food is inside the esophagus but the bulge can intrude into the trachea so it has more room. If the rings were solid and round then food would have a much more difficult time moving to the stomach. I hope this makes some sense.