{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:36:30Z","timestamp":1760142990942,"version":"build-2065373602"},"reference-count":39,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,19]],"date-time":"2024-01-19T00:00:00Z","timestamp":1705622400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001711","name":"Swiss National Foundation","doi-asserted-by":"publisher","award":["31003A_176038"],"award-info":[{"award-number":["31003A_176038"]}],"id":[{"id":"10.13039\/501100001711","id-type":"DOI","asserted-by":"publisher"}]},{"name":"ERAfrica RDS-Control NI 036 project","award":["31003A_176038"],"award-info":[{"award-number":["31003A_176038"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>The Ostrich occupies a unique position as the largest bird on the planet. Like other ratites, it has been reputed to have a phylogenetically primitive lung. We used macroscopy, light microscopy, transmission and scanning electron microscopy as well as silicon rubber casting to elucidate the functional design of its lung and compare it with what is already documented for the avian species. The neopulmonic region was very small and poorly developed. The categories of the secondary bronchi (SB) present and their respective numbers included laterodorsal (8\u201310), lateroventral (4\u20135), medioventral (4\u20136) and posterior (16\u201324). The lateral aspects of the laterodorsals were covered with a transparent collapsible membrane internally lined with a squamous to cuboidal epithelium. The bulk of these SB were in close proximity to intercostal spaces and the intercostal muscles and were thought to be important in the propulsion of gases. The lung parenchyma was rigid, with the atria well supported by septa containing smooth muscles, connective tissue interparabronchial septa were absent, and blood capillaries were supported by epithelial bridges. There were two categories of epithelia bridges: the homogenous squamous type comprising two leaflets of type I cells and the heterogeneous type consisting of a type I pneumocyte and type II cell. Additional type two cells were found at the atrial openings as well as the walls of the infundibulae and the air capillaries. The atria were shallow and opened either directly into several air capillaries or into a few infundibulae. The presence of numerous type II cells and the absence of interparabronchial connective tissue septa may imply that the ostrich lung could be capable of some degree of compliance.<\/jats:p>","DOI":"10.3390\/ani14020316","type":"journal-article","created":{"date-parts":[[2024,1,19]],"date-time":"2024-01-19T07:00:32Z","timestamp":1705647632000},"page":"316","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Anatomical and Functional Study of the Ostrich (Struthio camelus) Lung through Macroscopic Analysis in Combination with Optical and Electron Microscopy Techniques"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9983-785X","authenticated-orcid":false,"given":"Andrew","family":"Makanya","sequence":"first","affiliation":[{"name":"Department of Veterinary Anatomy and Physiology, Riverside Drive, Chiromo Campus, University of Nairobi, Nairobi P.O. Box 30197-00100, Kenya"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5062-1169","authenticated-orcid":false,"given":"Valentin","family":"Djonov","sequence":"additional","affiliation":[{"name":"Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3000 Berne, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1046\/j.1344-3941.2002.00024.x","article-title":"Anatomical and physiological characteristics of ostrich (Struthio camelus var. domesticus) meat determine its nutritional importance for man","volume":"73","author":"Cooper","year":"2002","journal-title":"Anim. Sci. J."},{"key":"ref_2","unstructured":"Farner, D., and King, J. (1971). Avian Biology, Academic Press."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1901","DOI":"10.2967\/jnumed.118.210310","article-title":"The use of ostrich eggs for in ovo research: Making preclinical imaging research affordable and available","volume":"59","author":"Freesmeyer","year":"2018","journal-title":"J. Nucl. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1523","DOI":"10.1093\/micmic\/ozad060","article-title":"Methods of in ovo and ex ovo ostrich embryo culture with observations on the development and maturation of the chorioallantoic membrane","volume":"29","author":"Makanya","year":"2023","journal-title":"Microsc. Microanal."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Pomraenke, M., Bolney, R., Winkens, T., Perkas, O., Pretzel, D., Theis, B., Greiser, J., and Freesmeyer, M. (2023). A Novel Breast Cancer Xenograft Model Using the Ostrich Chorioallantoic Membrane\u2014A Proof of Concept. Vet. Sci., 10.","DOI":"10.3390\/vetsci10050349"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2313","DOI":"10.1242\/jeb.204.13.2313","article-title":"A qualitative and quantitative study of the lung of an ostrich, Struthio camelus","volume":"204","author":"Maina","year":"2001","journal-title":"J. Exp. Biol."},{"key":"ref_7","first-page":"317","article-title":"An anatomical study of the respiratory air sacs in ostriches","volume":"66","author":"Bezuidenhout","year":"1999","journal-title":"Onderstepoort J. Vet. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1016\/0300-9629(93)90409-W","article-title":"Morphometries of the avian lung: The structural-functional correlations in the design of the lungs of birds","volume":"105","author":"Maina","year":"1993","journal-title":"Comp. Biochem. Physiol."},{"key":"ref_9","unstructured":"Makanya, A.N. (2017). The Biology of the Avian Respiratory System, Springer International Publishing."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1002\/jemt.20608","article-title":"Development and spatial organization of the air conduits in the lung of the Domestic Fowl, Gallus gallus variant domesticus","volume":"71","author":"Makanya","year":"2008","journal-title":"Microsc. Res. Tech."},{"key":"ref_11","first-page":"621982","article-title":"Three-Dimensional Structure and Disposition of the Air Conducting and Gas Exchange Conduits of the Avian Lung: The Domestic Duck (Cairina moschata)","volume":"2014","author":"Makanya","year":"2014","journal-title":"ISRN Anat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1685","DOI":"10.1002\/ar.21002","article-title":"Three-dimensional serial section computer reconstruction of the arrangement of the structural components of the parabronchus of the Ostrich, Struthio camelus lung","volume":"292","author":"Maina","year":"2009","journal-title":"Anat. Rec."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1475","DOI":"10.1111\/brv.12292","article-title":"Pivotal debates and controversies on the structure and function of the avian respiratory system: Setting the record straight","volume":"92","author":"Maina","year":"2017","journal-title":"Biol. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"477","DOI":"10.1111\/j.1469-7580.2005.00413.x","article-title":"A 3D digital reconstruction of the components of the gas exchange tissue of the lung of the Muscovy Duck, Cairina moschata","volume":"206","author":"Woodward","year":"2005","journal-title":"J. Anat."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"851574","DOI":"10.3389\/fanim.2022.851574","article-title":"Perspectives on the Structure and Function of the Avian Respiratory System: Functional Efficiency Built on Structural Complexity","volume":"3","author":"Maina","year":"2022","journal-title":"Front. Anim. Sci."},{"key":"ref_16","first-page":"89","article-title":"3D Computer Reconstruction of the Airway and the Vascular Systems of the Lung of the Domestic Fowl, Gallus gallus variant domesticus","volume":"5","author":"Maina","year":"2021","journal-title":"J. Appl. Math. Comput."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1002\/jmor.21340","article-title":"Anatomy, variation, and asymmetry of the bronchial tree in the African grey parrot (Psittacus erithacus)","volume":"282","author":"Lawson","year":"2021","journal-title":"J. Morphol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1002\/jemt.20887","article-title":"Spatial and functional relationships between air conduits and blood capillaries in the pulmonary gas exchange tissue of adult and developing chickens","volume":"74","author":"Makanya","year":"2011","journal-title":"Microsc. Res. Tech."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1111\/ahe.12615","article-title":"Slight volume changes in the Duck lung do not imply a fundamental change in the structure of the parenchyma","volume":"50","author":"Makanya","year":"2021","journal-title":"Anat. Histol. Embryol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1007\/s00441-016-2549-9","article-title":"Critical appraisal of some factors pertinent to the functional designs of the gas exchangers","volume":"367","author":"Maina","year":"2017","journal-title":"Cell Tissue Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.resp.2009.09.011","article-title":"Inspiratory aerodynamic valving occurs in the ostrich, Struthio camelus lung: A computational fluid dynamics study under resting unsteady state inhalation","volume":"169","author":"Maina","year":"2009","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1002\/aja.1000190306","article-title":"The embryology of the bird\u2019s lung. Based on observations of the Domestic Fowl. Part 1","volume":"19","author":"Locy","year":"1916","journal-title":"Am. J. Anat."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.resp.2011.11.005","article-title":"Pre-hatch lung development in the ostrich","volume":"180","author":"Makanya","year":"2012","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Makanya, A. (2015). The Vertebrate Blood-Gas Barrier in Health and Disease: Structure, Development and Remodeling, Springer.","DOI":"10.1007\/978-3-319-18392-3"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1002\/dvdy.20627","article-title":"Epithelial transformations in the establishment of the blood-gas barrier in the developing chick embryo lung","volume":"235","author":"Makanya","year":"2006","journal-title":"Dev. Dyn."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1002\/bdrc.21120","article-title":"Membrane mediated development of the vertebrate blood-gas-barrier","volume":"108","author":"Makanya","year":"2016","journal-title":"Birth Defects Res. C Embryo Today"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"101597","DOI":"10.1155\/2013\/101597","article-title":"Development and remodeling of the vertebrate blood-gas barrier","volume":"2013","author":"Makanya","year":"2013","journal-title":"Biomed. Res. Int."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1111\/joa.13358","article-title":"Anatomy, ontogeny, and evolution of the archosaurian respiratory system: A case study on Alligator mississippiensis and Struthio camelus","volume":"238","author":"Schachner","year":"2021","journal-title":"J. Anat."},{"key":"ref_29","first-page":"67","article-title":"The lung of the Emu, Dromaius novaehollandiae: A microscopic and morphometric study","volume":"163","author":"Maina","year":"1989","journal-title":"J. Anat."},{"key":"ref_30","unstructured":"Nickel, A., Schummer, R., and Seiferle, E. (1977). Anatomy of the Domestic Birds, Verlag Paul-Parey."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1017\/S1431927613014050","article-title":"Casting Materials and their Application in Research and Teaching","volume":"20","author":"Haenssgen","year":"2014","journal-title":"Microsc. Microanal."},{"key":"ref_32","first-page":"487","article-title":"The comparative anatomy of the respiratory pathways in the Domestic Fowl (Gallus domesticus), Pigeon (Columbia livia) and Domestic Duck (Anas platyrhynchos)","volume":"94","author":"Akester","year":"1960","journal-title":"J. Anat."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1959","DOI":"10.1152\/japplphysiol.91570.2008","article-title":"Parabronchial angioarchitecture in developing and adult chickens","volume":"106","author":"Makanya","year":"2009","journal-title":"J. Appl. Physiol."},{"key":"ref_34","unstructured":"West, J.B. (2011). Comprehensive Physiology, Wiley."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"R1625","DOI":"10.1152\/ajpregu.00459.2009","article-title":"Comparative physiology of the pulmonary blood-gas barrier: The unique avian solution","volume":"297","author":"West","year":"2009","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1016\/j.resp.2009.12.010","article-title":"Structure\u2013function studies of blood and air capillaries in chicken lung using 3D electron microscopy","volume":"170","author":"West","year":"2010","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"792","DOI":"10.1086\/652244","article-title":"Recent advances into understanding some aspects of the structure and function of mammalian and avian lungs","volume":"83","author":"Maina","year":"2010","journal-title":"Physiol. Biochem. Zool."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.resp.2005.12.009","article-title":"The honeycomb-like structure of the bird lung allows a uniquely thin blood-gas barrier","volume":"152","author":"West","year":"2006","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.resp.2006.05.005","article-title":"Spectacularly robust! Tensegrity principle explains the mechanical strength of the avian lung","volume":"155","author":"Maina","year":"2007","journal-title":"Respir. Physiol. Neurobiol."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/2\/316\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T13:45:59Z","timestamp":1760103959000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/2\/316"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,1,19]]},"references-count":39,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["ani14020316"],"URL":"https:\/\/doi.org\/10.3390\/ani14020316","relation":{},"ISSN":["2076-2615"],"issn-type":[{"type":"electronic","value":"2076-2615"}],"subject":[],"published":{"date-parts":[[2024,1,19]]}}}