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Caudal Pole (caudal + pole)
Selected AbstractsMeasurement of the linear dynamics of the descent of the bovine fetal testisJOURNAL OF ANATOMY, Issue 1 2003M. J. Edwards Abstract Measurements were made on 86 male bovine fetuses collected from abattoirs in the vicinity of Sydney, Australia. The fetal body length was used to calculate the approximate day of gestational age (DGA); most fetuses were between 60 and 150 DGA. The distances from the caudal pole of the kidney (metanephros) to, respectively, the tip of the scrotum, the distal end of the testis and the internal ring of the inguinal canal were measured, as well as the dimensions of the testis and gubernaculum testis. Distances of (1) testis to inguinal canal, (2) inguinal canal to scrotum, (3) testis to scrotum and (4) gubernaculum to scrotum were calculated from these measurements, which were made on both left and right sides. The total length of the gubernaculum testis increased during transabdominal passage and during transinguinal passage of the testis. Furthermore, the gubernaculum appeared to maintain the testis at a relatively fixed distance from the scrotum during transabdominal passage so that the inguinal canal appeared to move towards the testis. The greatest distance between the testis and the tip of the scrotum was found during the transinguinal passage of the testis and was 2.8 cm for the left testis and 2.3 cm for the right. When located within the scrotum, each testis was still 1.6,1.7 cm from the tip of the scrotum, so the distance to be traversed was only 0.6,1.2 cm. Following passage of the testis through the inguinal canal, the gubernaculum became shorter and its distal tip was displaced toward the distal end of the scrotum. Traction by the gubernaculum could account for the final transposition of the testis from the external inguinal ring to the scrotum. Other factors involved in displacement of the testis include differential growth patterns as well as increases in the dimensions of the testis itself. [source] The Development of the Epicardium in the Sturgeon Acipenser naccariiTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 10 2009José M. Icardo Abstract This article reports on the development of the epicardium in alevins of the sturgeon Acipenser naccarii, aged 4,25 days post-hatching (dph). Epicardial development starts at 4 dph with formation of the proepicardium (PE) that arises as a bilateral structure at the boundary between the sinus venosus and the duct of Cuvier. The PE later becomes a midline organ arising from the wall of the sinus venosus and ending at the junction between the liver, the sinus venosus and the transverse septum. This relative displacement appears related to venous reorganization at the caudal pole of the heart. The mode and time of epicardium formation is different in the various heart chambers. The conus epicardium develops through migration of a cohesive epithelium from the PE villi, and is completed through bleb-like aggregates detached from the PE. The ventricular epicardium develops a little later, and mostly through bleb-like aggregates. The bulbus epicardium appears to derive from the mesothelium located at the junction between the outflow tract and the pericardial cavity. Strikingly, formation of the epicardium of the atrium and the sinus venosus is a very late event occurring after the third month of development. Associated to the PE, a sino-ventricular ligament develops as a permanent connection. This ligament contains venous vessels that communicate the subepicardial coronary plexus and the sinus venosus, and carries part of the heart innervation. The development of the sturgeon epicardium shares many features with that of other vertebrate groups. This speaks in favour of conservative mechanisms across the evolutionary scale. Anat Rec, 2009. © 2009 Wiley-Liss, Inc. [source] Development of the Mesonephros in Camel (Camelus dromedarius)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2007K. H. Aly Summary The study of the development of the mesonephros in the camel (Camelus dromedarius) was carried out on 16 embryos ranging from 0.9 to 8.6 cm crown vertebral rump length (CVRL). At 0.9 cm CVRL, the mesonephros is represented by a narrow strip along the roof of the thoracolumbar part of the vertebral column. At 1.4 cm CVRL, some of the mesonephric tubules are canalized but others are still solid. The mesonephric corpuscles are well developed at 1.9 cm CVRL and occupy almost the entire abdominal cavity in between the liver and the gut. Histologically, the glomeruli occupy the ventromedial aspect of the mesonephros while the mesonephric tubules become numerous, larger and more coiled. At 3 cm CVRL, the metanephros is invaginated in the caudal pole of the mesonephros, and the mesonephric tubules in some areas are differentiated into secretory and collecting tubules. At 3.5 cm CVRL the mesonephros is related dorsally to the postcardinal vein and ventrally to the subcardinal vein. At 4.7 cm CVRL continuous regression of the mesonephros from cranialwards to caudalwards is observed. At 5.3,5.5 cm CVRL, the cranial part of the mesonephros is divided into medial and lateral regions, and later the medial region completely disappears and is replaced by the primordium of the adrenal gland. At 8.6 cm CVRL, the caudal part of the mesonephros completely disappears. [source] Systematization, Distribution and Territory of the Middle Cerebral Artery on the Brain Surface in Chinchilla (Chinchilla lanigera)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009A. C. P. De Araujo Summary The aim of the present study was to analyse thirty chinchilla (Chinchilla lanigera) brains, injected with latex, and to systematize and describe the distribution and the vascularization territories of the middle cerebral artery. This long vessel, after it has originated from the terminal branch of the basilar artery, formed the following collateral branches: rostral, caudal and striated (perforating) central branches. After crossing the lateral rhinal sulcus, the middle cerebral artery emitted a sequence of rostral and caudal convex hemispheric cortical collateral branches on the convex surface of the cerebral hemisphere to the frontal, parietal, temporal and occipital lobes. Among the rostral convex hemispheric branches, a trunk was observed, which reached the frontal and parietal lobes and, in a few cases, the occipital lobe. The vascular territory of the chinchilla's middle cerebral artery included, in the cerebral hemisphere basis, the lateral cerebral fossa, the caudal third of the olfactory trigone, the rostral two-thirds of the piriform lobe, the lateral olfactory tract, and most of the convex surface of the cerebral hemisphere, except for a strip between the cerebral longitudinal fissure and the vallecula, which extended from the rostral to the caudal poles bordering the cerebral transverse fissure. [source] | ||||||||||