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/3-in-1 Nerve Block. Femoral and/or 3-in-1 nerve blocks are used for surgical procedures on the front portion of the. thigh down to the knee and postoperative analgesia. Both blocks are carried out in a similar manner. The differences will be discussed in the technique section.