Quantitative studies on the development of the bronchi and bronchial glands of the pig from birth to maturity.
Cross-sectional areas of bronchi and bronchial glands of pigs aged from 1 day to 10 months were measured using image analysis. Growth of the bronchial glands was slow for the first month of life, reached a maximum between 1 and 3 months, and slowed again after 5 months. Mucous gland sizes fell into two groups, one included the apical, cardiac and accessory lobes, the other the diaphragmatic lobes. From birth to maturity the percentage increase in mucous gland area of all lobes was very similar. For the anterior lobes, mucous glands and bronchial lumina grew in direct proportion to each other. Up to 1 month of age the bronchial lumina of the diaphragmatic lobes grew but the glands did not. Later, glands and lumina grew in direct proportion. From birth to maturity the percentage increase in bronchial cross-sectional area was similar for all lobes.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001980:Bronchi / Q000254:growth & development*; D005088:Exocrine Glands / Q000254:growth & development*; D005260:Female; D008297:Male; D009093:Mucus; D010503:Periodic Acid-Schiff Reaction; D013552:Swine / Q000254:growth & development*