4-Piece BronchusThe 4 piece Bronchus model is a 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