ORIGINAL ARTICLE Histometrical study of the different parts of ureter in one-humped camel Sara Monjezi & Ahmadali A. Mohammadpour & Morteza Behnamrasouli Received: 26 July 2012 / Accepted: 7 November 2012 # Springer-Verlag London 2012 Abstract Dromedary camel is an essential source of food and milk in many parts of the world. Functional urinary system is vital for this animal to survive in hot climate. Production of highly concentrated urine is an important adaptation for dromedary camel to live in such dry and hot environment. The aim of this study was to study the micro- scopic structures of ureter and compare its three parts and its different layers in adult male dromedary camels. Six adult male one-humped camels aged between 7 and 11 years were used in this study. Tissue samples of the upper, middle, and lower part of ureter were collected and subjected to hema- toxylin and eosin, Masson’ s trichrome and periodic acid– Schiff staining. Histological studies revealed three layers in the ureter wall including tunica mucosa, tunica muscularis, and tunica adventitia. Ureter was covered by folded transi- tional epithelium on mucosal surface. The collagen and elastic fibers and many nervous endings were seen in lamina propria, while no goblet cells, submucosal mucous glands, and muscularis mucosae were identified. Tunica muscularis consisted of smooth muscles tunica adventitia was composed of areolar connective tissue with blood and lymphatic vessels and nerve endings. Our data analysis indicated that the mean ureter diameter as well as tunica muscularis and tunica adven- titia in the upper part was significantly (P >0.05) greater than the lower part. There was no significant difference between various parts of ureter in the left and right sides, and also no significant difference was observed between other parts of ureter. The results obtained in this study could be used to improve experimental urologic studies. Keywords Histometry . Dromedary camel . Ureter Introduction The one-humped camel (Camelus dromedarius) or Arabian camel is an essential source of food and milk in many parts of the world, especially in the African and Asian developing countries. Camels are able to survive in high temperature and dry environments like deserts. The anatomical, physiological, and behavioral characteristics of these animals that let them to survive in such hard conditions and also produce milk and meat are very unique. These properties make camels dis- tinctly superior to other domestic livestock especially in the desert-like ecosystem (Yaqoob and Nawaz 2007). Camel husbandry has a crucial role in the life of the people who live in desert areas of Iran. Compatibility of various mam- malian species to different habitats is due to various adapta- tions in cellular, physiological, and behavioral levels (El- Gohary et al. 2008; El-Gohary 2009). All the physiological functions of camel are conceived to be adapted to water and food restrictions (Ouajd and Kame 2009). The camel is able to regulate colon absorption and kidneys excretion of water and ions (Ouajd and Kame 2009). Kidneys of a camel are known to play a vital role in water retention through the production of highly concen- trated urine (Schmidt-Nielsen 1964; Abdalla and Abdalla 1979). S. Monjezi Department of Anatomical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran e-mail: Sara_monjezi@yahoo.com A. A. Mohammadpour (*) Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, P.O. Box 1793, Mashhad, Iran e-mail: mohammadpoor@ferdowsi.um.ac.ir M. Behnamrasouli Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Comp Clin Pathol DOI 10.1007/s00580-012-1652-x