The area behind the knee is called the popliteal. This term refers to all the anatomical structures in that area. The popliteal fossa is the shallow depression located behind your knee and is sometimes called the knee pit. The popliteal fossa has lateral and medial boundaries.
The fat in the popliteal fossa contains the popliteal lymph nodes. The bones of the popliteal fossa include the femur and tibia. The popliteal artery supplies the knee joint with blood and is an extension of the femoral artery. The knee is one of the largest and most complex joints of the human body.