Biomaterial Database

Lung development in the marsupial bandicoot, Isoodon macrourus. 1986

R T Gemmell

Department of Anatomy, University of Queensland, St Lucia, Brisbane, Australia.

The transformation of the terminal sacs present in the newborn into the alveoli observed in the adult, and the tissue and cellular composition of the interalveolar septum at various stages of lung development, were examined in the developing bandicoot. Lungs from 22 bandicoots, aged from 1 day postpartum to adult, were fixed with a glutaraldehyde/formaldehyde fixative and processed for examination of their structure. The respiratory region of the newborn lung is formed from terminating sacs, approximately 300-500 microns in diameter, which are delineated by thick connective tissue septa, have a highly vascularised internal lining and are present from birth until approximately Day 35 postpartum. The large blind sacs are then gradually replaced by alveoli, approximately 80 microns in diameter. In the juvenile and adult bandicoot, the connective tissue septa of the sacs are no longer discernible and a larger area of the blood capillaries of the lung is adjacent to the air within the alveoli. The changes in lung structure throughout pouch life probably reflect the increased respiratory requirements of the developing young. Although the time sequence of lung development in the eutherian differs from that in the marsupial, the adult form of the lung in both animal groups is similar in structure.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008394	Marsupialia	An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.	Metatheria,Marsupials,Marsupial
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D011650	Pulmonary Alveoli	Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.	Alveoli, Pulmonary,Alveolus, Pulmonary,Pulmonary Alveolus
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D002196	Capillaries	The minute vessels that connect arterioles and venules.	Capillary Beds,Sinusoidal Beds,Sinusoids,Bed, Sinusoidal,Beds, Sinusoidal,Capillary,Capillary Bed,Sinusoid,Sinusoidal Bed
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia