21. Surrounding these in the trachea and bronchi are cartilage rings, which help to maintain stability. 22. A number of smaller airways known as the bronchi ( both potentially causing respiratory failure ). 23. He discovered in 1812 that the actual source for a deep and pleasant trachea and bronchi . 24. The doctor finds out that Toundi's ribs are broken and have punctured his bronchi . 25. Lymphoid nodules form at the point of attachment of the worms in the bronchi and trachea. 26. Postganglionic parasympathetic fibers will release acetylcholine causing the constriction of the smooth muscle layer surrounding the bronchi . 27. They may occur along the membranous part of the trachea, the main bronchi , or both. 28. The bronchi in the conducting zone are reinforced with hyaline cartilage in order to hold open the airways. 29. In humans, the trachea divides into the two main bronchi that enter the roots of the lungs. 30. The bronchi continue to divide within the lung, and after multiple divisions, give rise to bronchioles.
