Morphometry and allometry of the postnatal lung development in the quokka wallaby ( Setonix brachyurus): a light microscopic study

• Published in: Respiratory physiology & neurobiology 2003-02, Vol.134 (1), p.43-55
• Main Authors: Makanya, A.N., Haenni, B., Burri, P.H.
• Format: Article
• Language: English
• Subjects: Air breathing; Animals; Animals, Newborn; Biological and medical sciences; Body Mass Index; Development, postnatal, lung; Fundamental and applied biological sciences. Psychology; Lung - anatomy & histology; Lung - cytology; Lung - growth & development; Lung Volume Measurements - methods; Macropodidae - anatomy & histology; Macropodidae - growth & development; Marsupial, quokka wallaby ( Setonix brachyurus); Morphometry, lung; Respiratory system: anatomy, metabolism, gas exchange, ventilatory mechanics, respiratory hemodynamics; Vertebrates: respiratory system
• ISSN: 1569-9048; 1878-1519
• DOI: 10.1016/S1569-9048(02)00204-5

The postnatally developing lungs of the quokka wallaby, Setonix brachyurus, were investigated macroscopically and by light microscopic morphometry. Lung, parenchymal and non-parenchymal volumes as well as the components of the latter two were analysed by regression analysis. The lungs comprised a single undivided left lung and a right lung with an adherent accessory lobe. Septal tissue growth was most remarkable in the canalicular and saccular stages. Between mid-canalicular stage and the saccular stage, the lung volume increased 2-fold, mainly due to airspace expansion, coupled with septal tissue thinning. The non-parenchymal vascular volume increase accelerated in the successive developmental stages while the airway and connective tissue volumes progressed in a decreasing order, being highest in the canalicular and saccular stages and lowest in the alveolar stage. Growth and remodelling of the alveolar septa occurred simultaneously with airspace subdivision. Airspace expansion accelerated during the stage of microvascular maturation, when most other parameters showed the least rate of increase.