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 entrapment. The femoral nerve is the first of two large nerves that supply the leg, the other being the sciatic nerve. The femoral nerve emerges from the mid to upper lumbar spine, whereas a sciatica originates from the lower back.