The great saphenous vein
Great saphenous vein · vena saphena magna
The longest vein in your body, running up the inside of your leg just under the skin.
What it does
The great saphenous vein starts on the inner side of the foot, passes in front of the inner ankle and runs up the inside of the leg and thigh to join the femoral vein in the groin. One-way valves along it stop blood falling back down.
Surprising fact
It is the longest vein in the body, and surgeons often harvest it to use as a bypass graft around blocked heart arteries.
Why it matters
When its valves weaken, blood pools and the vein swells into varicose veins. Moving often and not standing still for long periods helps.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.