Gross anatomy of the heart in Ostrich [Struthio camelus]

Today, with emphasis on the mechanical heart and heart transplantation from one human to another and one species to another, a knowledge of the anatomy of the bird's heart could contribute to these accomplishments. Eight male adult ostriches were used to study the heart macroscopically. This study revealed that the ostrich heart has some different features from the other birds, In the ostrich, fibrous pericardium as sternopericardial ligament attaches along the thoracic surface of the sternum. The central edge of muscular valve hangs down into the right ventricle and gives attachment to its rough parietal wall by a thick muscular stalk. The left and right pulmonary veins enter the left atrium independently and their openings were completely separated from each other by a septum. In the heart of the ostrich, the moderator bands were found in both the right and left ventricles in different locations. The right ventricle presents one tendinous moderator band near the base of the ventricle that extends from septum to the muscular valve. Also the moderator bands as tendinous thread like or flat sheet are usually present at about apex of the right ventricle that extends from septum to the parietal wall. In the left ventricle, there were some tendinous moderator bands close to the apex that extends from septum to the parietal wall and between trabeculae carneae of the parietal wall

Histomorphometric study of the spinal cord segments in the chick and adult male ostrich [Struthio camelus]

In this study, the vertical, transverse and oblique diameters of the spinal cord segments [C1, C6, C12, C18, T1, T4, L1, L4, L6 and L8] and the ratio of gray matter to white matter in chick [I month] and adult [18 months] male ostriches, each group consisted of 3 animals, were measured with standard micrometric method using 6 microm thick sections by light microscope. With advancement of age, the ratio of gray matter to white matter was reduced but the diameters of spinal cord segments were increased. Statistically, there were significant differences in parameters measured between the two age groups [P<0.05]

Investigation on the morphologic and morphometric changes in perikaryon and nucleus of spinal neuron during prenatal and postnatal life of male dogs

To study the growth process of perikaryon and nucleus of spinal neurons, 15 domestic male dogs in 5 age groups including 42-day-old fetus, 52-day-old fetus, newborn 6-month-old and adult dogs were studied. After preparation of animals, the spinal cord was dissected and then the spinal segments were studied by light and electron microscopy. The results of the present study showed that the maximum diameter of perikaryon and nucleus in all age groups belonged to the eighth cervical segment and the minimum diameter of nucleus belonged to the first coccygeal segment in 42-day-old fetus, the seventh thoracic segment in 52-day-old fetus, first coccygeal segment in newborn and the fourth thoracic segment in 6-month-old and adult animals, respectively. The minimum diameter of perikaryon in all age groups belonged to the first coccygeal segment except in 42-day-old fetus, which was related to the fourth thoracic segment

effect of age and sex on the esophageal wall structure in dogs

The aim of this project was to study the influence of the sex and age factors on the wall structure of the esophagus of the dog. Eighteen mixed breed dogs, [9 male and 9 female] in three age groups [3 neonate, 3 sexually mature and 3 old] were used. Animals were euthanized and after removing the whole esophagus, full thickness transverse sections were cut from the proximal, middle and distal parts. Microscopic sections of these samples were prepared and then examined for minimum and maximum thicknesses of the tunicae mucosa, submucosa and muscularis. Due to the absence of lamina muscularis mucosa in the proximal part of canine esophagus, the tunicae mucosa and submucosa in this region were collectively named tunica mucosa-submucosa. Results obtained from this study showed that there is a large increase in the thickness of tunica mucosa-submucosa and mucosa, from neonatal to sexually mature stages followed by a smaller increase between sexually mature and old stages in both sexes. We also found that the thickness of the mucosal layer is greater in distal part of esophagus than its middle part in all three age groups and both sexes. The thickness of tunica submucosa of the middle and distal parts and tunica muscularis of the proximal, middle and distal parts of esophagus showed a large increase between neonatal and sexually mature stages followed by a smaller decrease between sexually mature and old stages in both sexes. Also we found that the thickness of the submucosal layer is greater in distal part of esophagus than its middle part in all three age groups and both sexes. The thickness of the muscular layer showed a progressive increase from proximal part to the distal part in all age groups and both sexes. The differences between the two sexes in the thickness of esophageal layers do not follow a constant pattern

[Some aspects of macroscopic and microscopic studies of placentation in camel [camelus dromedarius]]

Salient aspects of a study on the placentation of camel at gross, light and electron microscopic levels are presented which included the analysis of various factors on five pregnant uteri. The observation confirmed that unlike other animals, in camel, the fetus only develops in the left born of the uterus. Based on the distribution and the type of the chorionic villi, the placenta was found to be in diffused form as in horse. At light microscopic level there were six layers between the fetal and maternal blood and thus the placenta of camel can also be classified as epitheliochorial form. The umbilical cord in camel is limited to the amniotic sac which is similar to cow and sheep but it contains two arteries, two veins and one urachus. Little amount of elastic fibers was also observed in the histolotgical and electron microscopical sections. At the electron microscopic level both binucleated and mononucleated cells in trophoblastic layer were confirmed. The study thus concludes that, unlike other ruminants, the camel placenta is similar to horse which is classified as diffuse, nondeciduated and epitheliochorial type