Femur or thigh bone. This image is 318 x 660 pixels; the original measures 1,820 x 3,260 pixels.
Illustration shows two views (anterior and posterior) of a left human femur (from Latin, femur - thigh), the long bone of the upper leg. The approximately hemispherical projection at the top of the bone is the head of femur which articulates (forms a joint - the hip joint - a ball and socket joint) with the pelvis (hip bone). This joint can deteriorate and a hip replacement might be required. Below the head is the neck of femur. The large bulge high at the base of the neck is called the greater trochanter (from Greek, trochanter - runner), the small bulge lower down on the opposite side is the lesser trochanter. The long part of the bone, or shaft, gives length to the upper leg.
The shaft widens at the bottom to form two bulges, the medial condyle and the lateral condyle (from Greek, kondylos - knuckle). The articular surface of the condyles meet the tibia (shin bone), forming the knee joint. This joint is covered at the front by the patella, or knee cap.