Compression of nerves in anatomical canals in the upper extremities is quite common. The cause of secondary compression is a change in the contents of the canal or its geometry, for example, in rheumatoid arthritis, intracanal tumors or trauma accompanied by damage to the canal walls. The etiology of primary compressions is still unclear. It is believed that the cause may be impaired blood circulation in the nerve and disruption of the blood-neural barrier. In this regard, understanding the anatomical aspects of the blood supply to the nerves of the extremities becomes incredibly relevant. The paper provides an overview of the available data on the options for blood supply to the nerves of the extremities. A theory has been put forward about the origin of the venoarterial reflex in the pathogenesis of compression neuropathy.