Al-Qadisiyah Journal of Veterinary Medicine Sciences

Abstract Camels possess remarkable physiological and anatomical adaptations that support survival in harsh desert environments. This study aimed to examine the microscopic architecture of the trachea and lungs in healthy adult one-humped camels (Camelus dromedarius) from Al-Diwaniyah Province, Iraq. Five camels of both sexes, aged 3–7 years, were examined post-slaughter. Tracheal and lung tissues were fixed in 10% neutral buffered formalin, processed through standard histological methods, sectioned at 6 µm, and stained with hematoxylin–eosin and Masson’s trichrome. Microscopic observations revealed that the tracheal wall comprised mucosa, submucosa, cartilage, and adventitia. The mucosal epithelium consisted of tall pseudostratified ciliated columnar cells with interspersed goblet cells, forming a mucociliary defense system. The lamina propria displayed loose connective tissue with abundant elastic fibers and blood vessels, while the submucosa contained sparse tubuloacinar mucus glands. The hyaline cartilage rings were encased in a well-defined perichondrium, and smooth tracheal muscle occupied the open ends of the rings. The lung parenchyma exhibited alveolar ducts lined by simple squamous epithelium, with alveoli containing type I and type II pneumocytes. Type I cells appeared thin and elongated, while type II cells were rounded and responsible for surfactant production. Statistical comparison with similar histological studies of ruminants showed structural similarities, indicating evolutionary conservation of respiratory tissue design (scoring index: tracheal epithelial height 9.5±0.3 µm; alveolar wall thickness 2.1±0.2 µm, p<0.05). These findings highlight camel respiratory specialization for efficient gas exchange and dust resistance under desert conditions.

Abstract The Euphrates jerboa, Allactaga euphratica, is a rodent which has adapted to life in a desert, and whose respiratory system is specialized to cope with dusty and inhospitable surroundings. This research sought to elaborate the anatomy, histomorphology, and histochemistry of the jerboa's trachea and bronchial tree through gross dissection and examination, resin casting, and routine histological staining. In total, fifteen adult male jerboas were separated into equal groups of anatomy, casting, and histology. In anatomical terms, the jerboa's trachea was a short, flexible tube with an average length of 0.7 ± 0.32 mm, and was comprised of eight cartilaginous rings shaped like the letter ‘C’. The right primary bronchus was more divided or branched than the left one, with the right forming a cranial, caudal, and accessory bronchus, and the left bronchus branching into three major branches. The resin casting confirmed and illustrated this asymmetry and the bronchial pattern which was efficient and presumably enhances the ventilation. Histology of the trachea illustrated four layers in the wall: the mucosa, submucosa, cartilage, and adventitia. The mucosa and the inner submucosa were lined with pseudostratified ciliated columnar epithelium with goblet cells which was poor in gland and immune cell elements. The cartilage rings were hyaline and the broad plate of the lamina bordered with resilient walls composed of lymphocyte and macrophage, which illustrated local defense and active local defense. According to statistical analysis, no significant difference was found among the measurements of the tracheae (P ≥ 0.05).