Anatomical variations in the origin and course of the human ophthalmic artery

The origin and course of the human ophthalmic artery was examined in order to describe the detailed anatomical features of the ophthalmic artery regarding its mode and site of origin and patterns of its course. Material and Through anatomical dissection, the origin of the ophthalmic artery was examined on both sides in 48 formalin fixed cadaveric heads. The exact site and mode of origin was described and the artery was carefully dissected along its proximal course to explore its mode of entrance into the orbital cavity and its relation to surrounding structures. In addition segments of the ophthalmic artery were excised and processed for histological examinations. The ophthalmic artery arises from the intracranial part of the internal carotid artery [intradural type of origin] in 46% of cases and in the other 54% of cases the origin of the ophthalmic artery is not seen in the cranial cavity and is defined as the extradural type of origin. In the intradural type of origin, the ophthalmic artery assumed two patterns to enter the orbit. In the first one, the artery penetrated the bony optic strut [trans-optic strut pattern]. In the second pattern the artery coursed into the optic canal above the optic strut [supra-optic strut pattern]. The site of origin of the ophthalmic artery was located on the anteriomedial, superiomedial, anteriolateral or medial aspect of the internal carotid artery. Histological examinations showed that the ophthalmic artery was of the medium-sized muscular type. Anatomical variations in the mode and site of origin of the ophthalmic artery as well as the patterns of its course should be put in consideration during planning for safe surgical procedures in this tight complex sellar and paraclinoid regions

ultrastructural study of the atrioventricular valves in the mice

Mice atrioventricular valves exhibit a number of morphological similarities to their human homologues. This research aimed to undertake a thorough study of the atrioventricular valves of mice. The success of treatment of the atrioventricular valve diseases is dependent on a thorough knowledge of its anatomy. In the present study, 20 mice of both sexes were used. The thoracic walls of the animals were opened, and the hearts were extracted and washed thoroughly with phosphate buffered saline. The annulus, leaflet tissue, chordae tendineae, and papillary muscles of the tricuspid and mitral valves were carefully dissected. The dissected specimens were processed for light and transmission electron microscopic examinations. The fine structure proved to be the same in both atrioventricular valves. The leaflets of the two AV valves were formed of a fibrous layer in its lower third [on the ventricular side] and a spongy layer in its middle third [on the atrial side] where the muscle cells were progressively lost. The fibrosa consisted of collagenous bundles that were differently oriented in right and left AV valves. The spongiosa was formed by a loose network of thin collagen fibers, fibroblasts and scattered elastic fibers. The chordae tendineae were structurally similar in the two AV valves where they were formed of three distinct layers: an outer layer of simple flattened endocardial cells, a basal lamina of loose collagen and few elastic fibres, and a central core of collagen with few scattered fibroblasts. The papillary muscles of the left ventricle extended from the heart apex toward the annulus fibrosus. In one third of specimens, the anterior papillary muscle has a free base that was always attached to the ventricular wall by thin chordae tendineae. The present study has demonstrated the microanatomy of the AV valves in mice, hoping at enhancement of human clinico- pathologic correlation when their functions become abnormal

Anomalies of the renal, phrenic, suprarenal arteries

This is a case where multiple anomalies of the posterior abdominal wall arteries were found in a single male cadaver aged 50-years. These anomalies were accessory renal, a pre-hilar division of the renal, unilateral origin of the inferior phrenic artery from the renal and aberrant suprarenal arteries. The accessory renal and the pre-hilar branch of the renal resembled polar arteries that supplied both poles of the right and the lower pole of the left kidney. The accessory renal and the pre-hilar branch, or their branches crossed in front of the hilar of the kidneys close to the ureteropelvic junction to reach the lower poles of the kidneys