BACKGROUND: The trachea is the main air passages which is important for taxonomic reasons. The structure of trachea varies considerably in different avian species. OBJECTIVES: This study has been carried out in order to determine the histological and histochemical structure of the trachea in ostriches. METHODS: Sixteen tracheas of 8 female and 8 male nine-month-old healthy blue-necked African ostriches in slaughterhouse of Isfahan were selected. Each trachea divided into cranial, middle and caudal portions and fixed in 10% neutral buffered formalin. Tissues sections were stained with H&E and special stains included Masson’s trichrome, Verhoeff’s, Foot’s, Van Gieson’s, Periodic acid-Schiff, and Alcian blue. RESULTS: The trachea of blue-neck ostriches was composed of tunica mucosa-submucosa, cartilaginous, muscular and serosa. The epithelium was ciliated pseudostratified columnar contained simple alveolar goblet mucous glands. These glands reacted negatively to Periodic acid-Schiff but positively to Alcian blue. The propria-submucosa was composed of dense connective tissue. The muscularis mucosa was absent. Tunica cartilaginous and muscular was made up of sternotrachealis muscle and cartilaginous rings. The rings were only composed of hyaline cartilage. There is no osseous tissue in the tracheal rings. Tunica serosa was composed of loose tissue contained parasympathetic ganglia, adipose tissues, vessels, and all the connective fibers. Three final cartilage rings were shaped tympanum of the syrinx. The histological structure of the trachea showed no significant differences between the male and female ostriches. Except for the decreased number of mucous glands in caudal portion of the trachea, the histological structures of the trachea showed no considerably differences among various portions. CONCLUSIONS: Based on this study, it can be concluded that although the histological and histochemical structure of the trachea in ostrich was similar to those of some other species, but that there were also some differences.

BACKGROUND: The Eustachian tube is an osteocartilaginous channel connecting the tympanic cavity with the nasopharynx. There is no anatomical and histological research performed on this organ in buffalo. OBJECTIVES: Anatomical and histological study of Eustachian tube in buffalo will be useful for basic knowledge of this organ. METHODS: For this study 8 adult male and female buffalo's head were provided from slaughter house and their Eustachian tube were studied anatomically, then tissue samples were obtained and paraffin sections were prepared for using of staining methods such as H&E (for general study), Verhoff (for elastic fibers), PAS (for carbohydrates) and Masson's Trichrome Stainning Kit (for collagen fibers). RESULTS: Anatomical results showed Eustachian tube was white and funnel- like tube, no curve and structurally supported by cartilage and in both sexes they had the same structure. Histological and Histochemical results showed the epithelium of Eustachian tube in buffalo is pseudostratified ciliated columnar and in some regions of the Eustachian tube epithelium was stratified squamous. In the first portion of Eustachian tube cartilage was elastic and then eustachian tube cartilage was hyaline. The glands of Eustachian tube in buffalo were mucous and non folicular tubal tonsil could be found around the pharyngeal opening with obviously lymphoid tissue. CONCLUSIONS:. The results of this research can be used as the basic anatomical and Histological knowledge in buffalo..

BACKGROUND: The histogenetic study is a useful and practical laboratory method for obtaining basic and effective information in order to reveal the process of histogenesis and development of organs in different stages during the embryonic period. This applied method helps us to understand the formation time of each organ and its tissue structure. OBJECTIVES: The aim of the present study was to study the histogenesis and histochemistry of the pheasant liver during the embryonic period. METHODS: Sixty fertile eggs were placed in the incubator and sampling was performed from day 5 to the end of incubation period. The liver samples were fixed in 10% Buffered Formalin and the slides were stained with Hematoxylin and Eosin (H&E), Periodic Acid Schiff (PAS) and Masson Trichrome (MT). RESULTS: In this study, liver parenchyma, changes in the hepatocytes and their glycogen storage, as well as the appearance time of canaliculi, biliary ducts, central veins and port spaces were investigated. CONCLUSIONS: Differences in the time of the formation of the organs and structures in various birds relate to different incubation period or species variations. In this research, as the first study on the liver histogenesis of the pheasant, the formation of this organ from the fifth day to the end of the fetal period was examined and it was observed that the evolution and tissue development of the liver is completed until the eighteenth day of incubation period.

BACKGROUND: Skin is the first line of defense against the external environment and and it is possible to maintain the natural physiological functions in the body. The mucus layer on the surface of the fish body contains anti-microbial combination that provides the first layer of defense against pathogens. The mucus is released by some of the epidermis cells which are called goblet cells and it mostly contains the mucin and other glycoproteins. OBJECTIVES: Histomorphometrical, Histochemical and Electron Microscopic Studies of Goblet Mucous Cells in Different Regions of Argyrosomus Hololepidotus Epidermis. METHODS: In this study, six Argyrosomus hololepidotus are used and the structure of the fish’s skin was studied. For doing this microscopic study, the sampling was done on dorsal Regions of fish with a thickness of 0.5µ then they were stained with H & E, PAS, AB (PH = 2.5) and AB (PH = 2.5)-PAS. For electron microscopic study, the samples after primary and post-fixation were dehydrated and were embedded in resin. Then, thin sections 50 μm were prepared and stained with uranyl acetate. RESULTS: Argyrosomus hololepidotus fish has maximum goblet cells in ventral and dorsal skin and minimum numbers of goblet cells were seen in tail skin in 100 µm length of epidermis. There were goblet mucous cells containing mucous in the Argyrosomus Hololepidotus epidermal that thier numbers were different in difference areas but mucus components were similar in different areas and they reacted positively to PAS and AB dyes with PH = 2.5.The electron microscopic results of this study were showed that goblet cells immigrate in thickness of epidermis and they include mucosal drops. CONCLUSIONS: There are goblet mucus cells in all parts of Argyrosomus Hololepidotus Epidermis and they have similar mucus nature.