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.
The first step of the femoral nerve block is to provide some sedation to the patient. This is usually the last part of the procedure you will remember. Once you are adequately sedated, the anesthesiologist will clean off your groin on the side of the planned surgery.