Features of lung morphology in the grass frog (Rana temporaria)
Abstract
One of the essential functions of the organism is to provide cells and tissues with oxygen and nutrients and to remove metabolic products, which is ensured by the respiratory organs. T he present study reports the results concerning the morphotopography and morphological structure of the lungs of the grass frog ( Rana temporaria familiaris L innaeus , 1758). The lungs of the frog are located in the cranial part of the body cavity, medially adjacent to the esophagus and ve n trally bordering the right and left atria of the heart. Laterally, the right lung is adjacent to the right lobe of the liver, whereas the left lung borders the cardiac part of the stomach. The lungs are paired organs of dark pink color formed by the right and left lungs, representing elongated, oval-shaped sac-like structures. Their absolute mass is 0.12 g, and the relative mass is 0.18%. According to the lung development index, which averages 42% (right lung – 43.1%, left lung – 41.8%), the lungs of the grass frog belong to the expanded - shortened type. The lung walls are formed by three layers: the outer layer, consis t ing of a thin layer of simple squamous epithelium and a layer of loose connective tissue; the middle layer, formed by dense regular connective tissue containing reticular and collagen fibers; the inner layer, lined with simple single-layered epithel i um under which there is a layer of loose connective tissue. The walls of the right and left lungs form folds and villous projections that branch into the depth of the organ cavity, thereby increasing the respiratory surface of the lungs. The vo l ume of the right lung is 216 mm³, while the volume of its cavity is 157 mm³; the ratio of the cavity volume to the total lung volume is 0.73%. In the left lung, the morphometric parameters are similar: the lung volume is 199 mm³, the cavity vo l ume is 147 mm³, and the ratio of the cavity volume to the total lung volume is 0.41%, which indicates the absence of pr o nounced asymmetry between the left and right lungs.References
Bodegas, M. E., Montuenga, L. M., & Sesma, P. (1995). Neuroendocrine diffuse system of the respiratory tract of Rana temporaria: An immunocytochemical study. General and Comparative Endocrinology, 100(2), 145–161.
Burggren, W. W., & West, N. H. (1982). Changing respiratory importance of gills, lungs and skin during metamorphosis in the bullfrog Rana catesbeiana. Respiration Physiology, 47(2), 151–164.
Carrasco-Medina, A. S., Salla, R. F., Sebben, A., da Silva, H. R., Passos, F. D., Toledo, L. F., & Rebouças, R. (2024). The cardiorespiratory system of miniature frogs. Journal of Anatomy, 244(2), 232–248.
Channing, A., & Willems, F. (2018). A new grass frog with rupicolous tadpoles from Northern Zambia (Anura: Ptychadenidae). Zootaxa, 4462(3), 349–366.
Davies, A., & Moores, C. (2010). Structure of the respiratory system, related to function. In: Davies, A., & Moores, C. The respiratory system. Churchill, Livingstone. Pp. 11–28.
Guangming, G., Zhe, Y., Mei, Z., Chenchen, Z., Jiawei, D., & Dongyu, Z. (2020). Comparative morphology of the lungs and skin of two Anura, Pelophylax nigromaculatus and Bufo gargarizans. Scientific Reports, 10(1), 11420.
Hassan, M., Melad, A. A. N., Zakariah, M. I., & Yusoff, N. A. H. (2023). Histopathological alterations in gills, liver and kidney of African catfish (Clarias gariepinus, Burchell 1822) exposed to Melaleuca cajuputi extract. Tropical Life Sciences Research, 34(2), 177–196.
Horalskyi, L. P., Khomych, V. T., & Kononskyi, O. I. (2019). Osnovy histolohichnoyi tekhniky i morfofunktsionalni metody doslidzhennia u normi ta pry patolohiyi [Basics of histological technique and morphofunctional methods of research in the norm and pathology]. Polissia, Zhytomyr (in Ukrainian).
Horalskyi, L. P., Tsanko, I. V., Gutyj, B. V., & Brygadyrenko, V. V. (2025). Features of the microscopic structure of the lungs of Clarias gariepinus of the catfish family. Regulatory Mechanisms in Biosystems, 16(2), e25050.
Horalskyi, L., Hlukhova, N., & Sokulskyi, I. (2020). Morphological traits of rabbit lung. Scientific Horizons, 23(8), 180–188.
Itsukushima, R., & Kano, Y. (2024). Fish fauna and environmental factors in river estuaries of small and medium-sized rivers on islands significantly influenced by warm currents. Journal of Fish Biology, 104(5), 1503–1512.
Jørgensen, C. B. (2000). Amphibian respiration and olfaction and their relationships: from Robert Townson (1794) to the present. Biological Reviews of the Cambridge Philosophical Society, 75(3), 297–345.
Liang, G. F., Li, C. X., Bai, X., Xu, H. X., & Ding, S. Y. (2019). Effects of environmental factors on the distribution of amphibians in agricultural landscape. Ying yong sheng tai xue bao = The Journal of Applied Ecology, 30(1), 301–308.
Maina, J. N. (1989). The morphology of the lung of the East African tree frog Chiromantis petersi with observations on the skin and the buccal cavity as secondary gas exchange organs: A TEM and SEM study. Journal of Anatomy, 165, 29–43.
Maina, J. N. (2002). Structure, function and evolution of the gas exchangers: Comparative perspectives. Journal of Anatomy, 201(4), 281–304.
Maina, J. N. (2014). Comparative respiratory physiology: The fundamental mechanisms and the functional designs of the gas exchangers. Open Access Animal Physiology, 6, 53–66.
McWhinnie, R. B., Sckrabulis, J. P., & Raffel, T. R. (2021). Temperature and mass scaling affect cutaneous and pulmonary respiratory performance in a diving frog. Integrative Zoology, 16(5), 712–728.
Ogunwole, G. A., Saliu, J. K., Osuala, F. I., & Odunjo, F. O. (2021). Chronic levels of Ibuprofen induces haematoxic and histopathology damage in the gills, liver, and kidney of the African sharptooth catfish (Clarias gariepinus). Environmental Science and Pollution Research International, 28(20), 25603–25613.
Perry, S. F., Wilson, R. J., Straus, C., Harris, M. B., & Remmers, J. E. (2001). Which came first, the lung or the breath? Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology, 129(1), 37–47.
Santin, J. M., & Hartzler, L. K. (2016). Control of lung ventilation following overwintering conditions in bullfrogs, Lithobates catesbeianus. The Journal of Experimental Biology, 219(13), 2003–2014.
Southwell, D. M., Heard, G. W., & McCarthy, M. A. (2018). Optimal timing of biodiversity offsetting for metapopulations. Ecological Applications, 28(2), 508–521.
Tattersall, G. J., Currie, S., & LeBlanc, D. M. (2013). Pulmonary and cutaneous O2 gas exchange: A student laboratory exercise in the frog. Advances in Physiology Education, 37(1), 97–105.
Tsaryk, Y. V., Khamar, I. S., & Dykyi, I. V. (2018). Zoolohiya khordovykh [Chordate zoology]. Lvivskyi Natsionadbnyi Universytet imeni Ivana Franka, Lviv (in Ukrainian).
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons «Attribution» 4.0 License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
