1 A ligand is any molecule that binds to a specific site on a protein or other molecule. In this case, the estrogen hormone 17-beta-estradiol is the ligand, and the estrogen receptor is the protein.  Binding turns on, or activates, a hormone receptor.
A femoral nerve block is a type of regional anesthesia in which the femoral nerve, located in the groin area, is deadened to allow surgery in the leg or knee area.
Femoral nerve block with local anesthetic and steroid is occasionally used in the treatment of persistent lower extremity pain when the pain is thought to be secondary to inflammation or when entrapment of the femoral nerve as it passes under the inguinal ligament is suspected.