Explain how the elbow joint of a human and a cow is similar, but not identical in structure

Both are warm blooded creatures. So you have humerus above and ulna beneath, which partake in the elbow joint. Both the dairy animals and human have pivot sort of joint with two insurance tendons to bolster the joint. The main distinction is that you have 180-degree pivot of humerus in human and not so on account of a dairy animals.