I WONDER - What Job Do Veins Do?

The video explains that veins hold about 70% of the body's blood, which travels to the heart and lungs to receive oxygen. The blood in veins is deoxygenated. The largest vein is the inferior vena cava, returning blood from the lower body to the heart, while the longest is the saphenous vein in the leg. Venules are small veins that connect larger veins to capillaries.

What percentage of the entire blood is held by veins?

What type of blood is carried by the veins?

What is the largest vein in the human body?

Where does the saphenous vein run in the body?

What are small narrow veins that link larger veins to capillaries called?