The femoral vein and artery (but not the nerve) are surrounded, for a short distance, by the femoral sheath. This is a sleeve of tissue which is a continuation of fascia from within the abdomen. There is no sheath present at birth, but it is pulled down as the limb grows.
On the medial side of the vein is a space (the femoral canal) which serves to allow expansion of the vein. It also provides a potential route for the herniation of abdominal organs (e.g. a loop of small intestine). Femoral hernias are more common in women than men.
