human) head. face is used when referring to physical features: a pretty face with high cheekbones. countenance, a more formal word, denotes the face as it is affected by or reveals a person's state of mind; hence, it often signifies the look or expression on the face: a thoughtful countenance.
Muscles Around the Knee. 1  Quadriceps femoris musclesâa large muscle group on the front of the thigh. 2  Vastus lateralisâpart of the quadriceps femoris on the outside-front of the thigh, it extends or straightens the leg and is controlled by the femoral nerve. Vastus lateralisâpart of the quadriceps femoris on the outside-front of the thigh, it extends or straightens the leg and is controlled by the femoral nerve. 2  Vastus intermediusâpart of the quadriceps femoris on the center-front of the thigh, it extends or straightens the leg and is controlled by the femoral nerve.
There are a variety of structures that surround the knee and allow it to bend and that protect the knee joint from injury. The quadriceps and hamstring muscles are responsible for moving the knee joint. When the quadriceps muscles (located on the front the thigh) contract, the knee extends or straightens.