Solisvaltimoiden

Solisvaltimoiden, commonly known as veins, are a critical component of the circulatory system in vertebrates. Their primary function is to transport deoxygenated blood from the body's tissues back to the heart. This contrasts with arteries, which carry oxygenated blood away from the heart. Veins are characterized by their thinner walls and less muscular structure compared to arteries, as the blood pressure within them is significantly lower.

Many veins, particularly those in the limbs, possess valves. These flap-like structures are crucial for preventing the backflow of blood, especially as blood needs to travel against gravity to return to the heart. The contraction of surrounding skeletal muscles also plays a vital role in propelling blood through the venous system, often referred to as the "skeletal muscle pump."

The venous system is extensive, forming a network that encompasses the entire body. From small venules that collect blood from capillaries to large veins like the vena cavae, which empty directly into the heart, this system is essential for maintaining blood circulation and oxygen delivery throughout the organism. Diseases affecting veins, such as varicose veins or deep vein thrombosis, can have significant health implications.