aderen

Aderen is the Dutch term for veins, the blood vessels that carry blood back toward the heart. In the systemic circulation, veins transport relatively deoxygenated blood from tissues, with the exception of the pulmonary veins, which return oxygenated blood from the lungs to the heart. Veins contrast with arteries in several key ways: walls are thinner, less muscular and elastic tissue, and they often have larger lumens and lower pressure. Many veins contain one-way valves that prevent backflow, particularly in the limbs.

Structure and organization

Veins are organized into superficial and deep systems. Superficial veins lie close to the skin and are often visible, while deep veins run alongside corresponding arteries and are the major conduits for returning blood from the limbs. The venous system includes large named vessels (such as the superior and inferior vena cava, internal and external jugular veins, renal veins, and the great and small saphenous veins) as well as numerous venules and smaller veins. Vein walls consist of three layers—tunica intima, tunica media, and tunica adventitia—with valves often present in the tunica intima to promote unidirectional flow.

Physiology and clinical relevance

Veins function as capacitance vessels, holding a substantial portion of the blood volume and aiding venous return through skeletal muscle pumps and respiratory movements. Clinically, veins are involved in conditions such as varicose veins, chronic venous insufficiency, deep vein thrombosis (DVT), venous ulcers, and phlebitis. Diagnosis commonly relies on duplex ultrasound; venography is less frequently used. Treatments range from compression therapy and lifestyle changes to anticoagulation for thrombotic conditions and various procedures for varicose veins.