[TA] anterior thigh muscles; origin, by four heads: rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis; insertion, patella, and thence by patellar ligament to tibial tuberosity; action, extends leg; flexes thigh by action of rectus femoris; nerve supply, femoral. SYN: musculus quadriceps femoris [TA], musculus quadriceps [TA], musculus quadriceps extensor femoris, quadriceps muscle of thigh.