In the origin of the arteria radialis a loop-like formation was found. This unusual arrangement can be explained in the following way: from both the a. brachiahs continuating into the a. ulnaris and the a. brachiahs superficialis continuating into the a. radialis, aa. recurrentes radiales branch off, which are connected by an anastomosis. The reduction of the a. brachiahs superficialis results in the fact that the aa. recurrentes radiales with their anastomosis have to take over the blood supply of the a. radialis and thus lead to the loop-like formation.