Laskimojärjestelmät

Laskimojärjestelmät, known in English as venous systems, refer to the network of veins that carry deoxygenated blood from the body's tissues back to the heart. These vessels are a crucial component of the circulatory system, working in tandem with the arterial system, which carries oxygenated blood away from the heart. Veins are generally thinner-walled and have larger lumens than arteries, reflecting the lower pressure within them.

A key feature of the venous system is the presence of valves. These one-way valves, located at intervals along the veins, prevent the backflow of blood, particularly in the limbs where blood must be pumped against gravity. Muscle contractions, especially in the legs, act as a pump, squeezing the veins and propelling blood towards the heart. This is often referred to as the muscle pump mechanism.

The venous system can be broadly categorized into superficial and deep veins. Superficial veins are located closer to the skin's surface, while deep veins run alongside arteries and are responsible for draining the majority of blood from the body. The two systems are interconnected by perforating veins.

Diseases and conditions affecting the venous system include varicose veins, deep vein thrombosis (DVT), and chronic venous insufficiency. Varicose veins occur when valves weaken, leading to blood pooling and swollen, twisted veins. DVT is a serious condition involving blood clots in deep veins, which can potentially travel to the lungs. Chronic venous insufficiency describes a long-term condition where veins struggle to return blood to the heart efficiently. Understanding the structure and function of the venous system is vital for diagnosing and treating these circulatory disorders.