The
patella , also known as the
kneecap or
kneepan, is a thick, circular-triangular
bone which articulates with the
femur (thigh bone) and covers and protects the anterior articular surface of the
knee joint. The patella is found in most vertebrates such as
mice,
cats, and
birds, but not in
whales or most reptiles and amphibians such as
snakes or
frogs.