INTRODUCTION: Complete appreciation of the cardiac venous system requires an understanding of its embryological basis, its usual patterns of distribution, and its common variations. AIM: The aim of our study was to improve our understanding of the coronary sinus morphometrical and topographical anatomy. METHODS: The investigations were carried out on 25 human hearts (from 11 male and 14 female persons of mean age 59.5; range: 40 to 75 years). The classic anatomical technique of microdissection (using neurosurgical microinstruments) was performed under the stereoscopic microscope on 10 specimens injected with a 10% formaldehyde solution. The arteries and veins of an additional 15 hearts were injected with methylmethacrylate and immersed in a 40% solution of NaOH for corrosion. Following washing out and drying, the obtained vascular casts were examined and measured. RESULTS: Coronary sinus (CS) extends from the opening of the oblique vein of the left atrium into the great cardiac vein, to its empty orifice into the right atrium. The length of CS varied between 22.4 and 41.4 mm (mean 33.0 ± 6.1 mm). The diameter of CS at its beginning was 5.0 - 9.6 mm (mean 6.6 ± 1.3 mm), and its diameter at its atrial mouth varied from 6.6 - 12.0 mm (mean 8.4 ± 1.6 mm). The CS had varied relationships to the branches of the left or right coronary arteries. It extended superficial and above the artery in 16 (64%) hearts, and close superficial to the artery in 9 (36%) cases. Duplication of the superior vena cava associated with an aberrant left hepatic vein was found in one case. The persistent left superior vena cava, which drained into the right atrium via the enlarged coronary sinus, was formed by the persistence of the left anterior cardinal vein. CONCLUSION: Our study shows that the coronary sinus, created in an early stage of embryological development, is an important collecting vessel receiving the main veins of the heart.

Introduction: The intracranial part of the optic nerve is perfused by the upper hypophyseal and ophthalmic arteries. Standard anatomical textbooks have not dealt with the vasculature of this clinicaly important part of the central nervous system. Objective: To study morphological characteristics of perioptical arterial vascularization of the intracranial part of optic nerve. Material and methods: The study was conducted on 18 whole brains of both sexes (11 male and 7 female), from the age of 51-78 years, with no signs of changes in the structures of the central nervous system. The vasculature of the optic nerves was microdissected and examined under the stereoscopic microscope after injecting their arteries with a 10% mixture of India ink and gelatin, and fixation in a 5% solution of formalin. Results: Intracranial segment of the optic nerve was richly supplied, from both, the ventral and the dorsal side, strictly with penetrating branches which come from the pial arterial network originating from the internal carotid artery and the superior hypophyseal artery for the ventral nervous surface, and from the anterior cerebral artery for the dorsal nervous surface. Conclusion: In accordance with the objective, and based on the obtained results, we confirmed that intracranial segment of the optic nerve has a rich and very delicate vascular network.