To elucidate the macroscopical and microscopical structure of dog's lacrimal gland, 15 adult dogs (Canis familiaris) were utilized in this study. Macroscopically, the lacrimal gland was located on the dorsolateral aspect of the eyeball and bounded dorsolaterally by the orbital ligament, zygomatic process of the frontal bone and frontal process of malar bone. Its shape was nearly rectangular with the average width (1.38 ± 0.13 cm) and length (1.52 ±0.12 cm). In between the dorsal and lateral rectus muscles, the lacrimal artery, vein and nerve were observed. Microscopically, the lacrimal gland was enveloped by the fibromuscular capsule and lobulated. Each lobule was formed of secretory endpieces and ducts. The secretory endpieces were mucous and serous. However, the mucous type was predominant. The lining cells of the secretory endpieces expressed a positive reaction to alcian blue and Periodic acid Shiff. A series of duct system within the lobules and septa was seen. The scanning electron microscopic examination revealed that the secretory endpieces covered with granular secretory substance. Several crystals with sharp taper ends were seen around the secretory endpieces.

Objective:As pecten oculi had great functional significances for ornithology, pecten oculi of Baladi duck was well-deserving of intensive morphological study. So, the aim of this study was to throw light on some anatomical and histological formation of the pecten oculi of Baladi ducks as well as use of scanning electron microscopy.Materials and Methods:Twenty eyeballs of 10 adult Baladi ducks were used to fulfill this work. Ten eyes were used to study the gross anatomy of pecten oculi, including the location, shape, and numbers of pleats. Five samples were embedded at 10% neutral buffered formalin. The specimens were examined by regular histological procedures. The latter five samples were applied for electron microscopy.Results:Grossly, the pecten oculi is formed of three portions: the base, emerged from the optic disk; the pleats, sorted in fan shape; and the bridge. The essential histological ingredients of Baladi ducks’ pecten oculi are the blood vessels, lymph vessels, pigment cells, and hyalocytes.Conclusion:The current work explains the primary macro- and micro-morphological features of pecten oculi in Baladi duck and collates these features to those formerly explained in other birds. Generally, pecten oculi of Baladi duck was analogous to that of the diurnal birds.

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This study aimed to characterize and evaluate normal temporomandibular joint (TMJ) of the Egyptian Baladi sheep anatomically and histologically as a large animal model. Fifteen heads of adult apparently healthy male sheep (Ovis aries) were utilized for; macro-and microscopical examination. Also, bony preparations, radiology, computed tomography and scanning electron microscopy were achieved. The TMJ consisted of mandibular condyle of the mandible, glenoid fossa of temporal bone and articular disc in-between. The mandibular condyle was flattened laterally, convex medially and slopped caudomedially. The glenoid fossa was elliptical in shape, concavoconvex from backward to forward. The disc was a smooth, elliptical plate, biconcave, thin centrally and thick peripherally with sloped end caudomedially. Histologically, the fibrocartilage layer of the condyle and glenoid fossa was differentiated into four zones; fibrous, proliferative, hypertrophic, and calcification zones. The fibrocartilagenous disc consisted of thick densely packed bundles of collagen fibers with chondrocytes in-between. The complex architecture of articular disc fibers was revealed by light and scanning electron microscopic examination. The collagen fibers orientation was perpendicular in the anterior and posterior regions, and parallel anteroposterior in the central region. There were many anatomical similarities between sheep and human TMJ in; relations, size, shape, position of the disc, histological structure and surgical approach. Furthermore, the sheep are more economic, available by large numbers, high ethical suitability, all this renders the sheep not only suitable but ideal choice as a large animal model over other animal models.

Compared to other mammals, Arabian camels are ideal models for exploring the structural adaptations that enable camels to survive in arid environments. Thus, this study aimed to explore how evolutionary adaptation to arid conditions modifies the characteristics of the kidneys in Arabian camels (Camelus dromedarius) compared to oxen. Urine samples were physically and chemically analyzed. Harvested kidneys were subjected to topographical and fast spin echo magnetic resonance (FSE-MR) imaging. Histology, histomorphometry, and Aquaporin-2 (AQP2) expression by immunohistochemistry were also performed. Here, in dromedaries, sodium and potassium values in the urine were much higher (p=0.001, for both), whereas chloride was much lower (p=0.004) than the values of oxen. Compared with oxen, the level of the hormone aldosterone in serum was significantly lower (p=0.002), whereas creatinine and urea were significantly higher (p=0.005 and p=0.001, respectively). Uric acid in dromedaries and oxen did not differ significantly (p=0.349). Like sodium levels (p=0.001) in dromedary serum, chloride was also much higher (p=0.002) than in oxen. The average value of potassium was much lower (p=0.009) than that of oxen. Morphologically, anatomical and FSE MRI studies revealed that minor and major calyces were not found in dromedary kidneys. The renal pelvis was not found in oxen, and the major calyx was directly connected to the ureter. The dromedary kidney contained a wider medullary portion as well as increased diameters for renal corpuscles (RCs), proximal convoluted tubules (PCTs), and collecting tubules (CTs, p<0.05) compared with the oxen. We also noted that AQP2 was significantly expressed in dromedary nephron components, except for RCs, compared with oxen as shown by immunohistochemistry. Overall, these data strongly suggest that the dromedary has a greater ability to adapt to harsh desert conditions in terms of producing highly concentrated urine than oxen.