Gross anatomy of the oropharyngeal cavity in the ostrich [Struthio camelus]

There are significant structural differences between the mouth and pharyngeal cavity of birds and mammals. It is usual to refer to a common oropharyngeal cavity of birds because the soft palate, which forms such an obvious delineation between the mouth and pharyngeal cavity, is absent. Six male adult ostriches were used to study the oropharyngeal cavity and its components including the beak, hard palate, pharynx, tongue and the larynx macroscopically. This study revealed that these components in ostrich have different features from other birds. In the ostrich, the beaks are spoon-shaped and the tongue is characterized by a short, broad and semicircular form. The hard palate is concave with a prominent median mucosal fold in its 2/3 rostral area and two oblique choanal slits in its caudal third area. The roof of pharynx presents infundibular slit in midline, a deep concave notch in caudal border and pharyngeal tonsils on its dorsal surface. The larynx protrudes from the floor of pharynx and consists of the unpaired cricoid cartilage and the paired arytenoid cartilages

stereological study on the liver in the early stages of streptozotocin-induced diabetes mellitus in rats

Diabetes mellitus is associated with an increased risk of certain complications including those involving the liver. However, most studies have focused on the biochemical, physiological and qualitative pathologic alterations of the liver in diabetes and the quantitative aspects of liver structure has received less attention. The aim of this study was to evaluate the quantitative changes in liver volume, volume-weighted mean volume of hepatocytes and their nuclei, and proportional and absolute volumes of liver sinusoids in streptozotocin-induced diabetic rats, using Stereological methods. Streptozotocin was injected to male rats and their livers were removed after 4, 8 and 12 weeks. Liver volume and weight were measured and uniform isotropic random sections of the liver were obtained using the orientator method and stained with Feulgen periodic acid schiff. Microscopic fields were chosen and volume-weighted mean volume of the hepatocytes and their nuclei were estimated using the point-sampled intercepts method in three histological zones of the liver acini. Proportional and absolute volumes of liver sinusoids were measured using point counting. The results showed that liver volume and weight and mean volume of the hepatocytes were mainly decreased 4 and 8 weeks after diabetes induction. The mean volume of hepatocytes nuclei decreased at 4, 8 and 12 weeks in diabetic rats. The absolute volume of liver sinusoids decreased 4 weeks after diabetes induction but no significant differences were noted after 8 and 12 weeks. From this study it can be concluded that induced diabetes mellitus in rats can alter liver volume, morphology of hepatocytes and their nuclei and sinusoids in the early stages of the disease