Model Size 3-7/8” x 1-1/2” x 1-3/4” Card Size 6-1/2” x 5-1/4” Base Size Several custom display options are available Four stage cross-section of the bronchus demonstrating the tissue changes occurring in asthma and chronic bronchitis. Four stages: normal bronchus, hypersecretion of the mucous gland, swelling with lymphoid aggregations and smooth-muscle spasm. The model includes: cartilage, mucous glands and plug, spiraling smooth muscles, and the fibroelastic connective tissue and epithelial layers of the bronchus. All stages rotate on hinge pin.