Vénarendszer

Vénarendszer is a term used in some contexts, particularly in older or specialized anatomical descriptions, to refer to the venous system of the body. This system comprises all the veins that carry deoxygenated blood from the body's tissues back to the heart. Veins are distinct from arteries, which carry oxygenated blood away from the heart.

The venous system is a complex network of vessels that mirrors the arterial system in many areas. Veins are generally thinner-walled and less muscular than arteries, as they operate under lower pressure. Many veins, especially in the limbs, contain valves. These flap-like structures prevent the backflow of blood, ensuring that it continues to move towards the heart, especially against gravity.

Blood flow through the veins is aided by several factors, including the contraction of surrounding skeletal muscles, which act as a pump, and pressure changes in the chest cavity during respiration. The largest vein in the body is the inferior vena cava, which collects blood from the lower body, and the superior vena cava, which collects blood from the upper body. Both empty into the right atrium of the heart. Diseases affecting the venous system include varicose veins, deep vein thrombosis (DVT), and phlebitis.