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.
Nerve blocks are injections of anaesthetic and steroid around a nerve or group of nerves to reduce and numb pain. Different kinds of nerve blocks are used for different purposes. Therapeutic nerve blocks are used to treat painful conditions. They contain local anaesthetic that can be used to control acute pain.