[Orbital veins and arteries in relation to the connective tissue system of the orbit].

Our study revealed that the relationships between the vessels and the connective tissue, which forms a constant and bilateral symmetrical system of connective tissue septa bordering adipose tissue compartments, are characteristics and constant but essentially different for veins and arteries. The arteries run within the adipose tissue compartments only contacting the connective tissue septa where they perforate them. As to the veins, their relationship with the connective tissue apparatus is completely different. These vessels run within the septa firmly connected with their connective tissue fibres, forming a continuity between the adventitia of the veins and the walls of the adipose tissue compartments. This difference between arteries and veins results in a different spatial structure for the two vascular systems. The arterial system is a radiating system, whereas the venous system is an anastomosing complex of venous rings which are arranged circularly inside as well as outside the muscle cone. It seems likely that the relationships of the vessels, particularly of the veins, with the connective tissue apparatus play an important role in the well-functioning of the orbital blood-circulation.