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 femoral nerve is one of the largest nerves in your leg. Itâs located near the groin and controls the muscles that help straighten your leg and move your hips. It also provides feeling in the lower part of your leg and the front of your thigh.