Wandering blood cells, especially lymphocytes and eosinophils, are usually found here. Slide 6 Longitudinal, parasagittal section of trachea showing a series of darkly stained cartilage rings cut across. Primary bronchi are essentially like the trachea in structure, and we have no example to show you. An intrapulmonary bronchus with several separate pieces of hyaline cartilage in its wall. A thin layer of bright pink smooth muscle lies between the cartilage and the mucosa.
Arterial branches accompany the branching respiratory tree all along the way.
An intrapulmonary bronchus with a patch of cartilage along its lower edge. Notice the field of alveoli and small branching terminals all around, typical of lung. Slide 9 Detail of previous wall, showing the large chondrocytes of the cartilage. The epithelium lining the lumen looks pseudostratified still. A layer of pink smooth muscle lies between it and the cartilage.