PA Anatomy: Limbs: Case 1

The oval region overlying the shaft of the femur is darker in color than the surrounding muscle, so it is made of fat. Most of the body tissues are similar in density: muscle, fascia, organs, blood, tumors, and watery fluids, and cannot be told apart on radiographs. But fat is low enough in density that it can be seen, usually as dark streaks when it is between structures, or as a darker layer of variable thickness in the subcutaneous region. Can you tell whether the fat collection is in the anterior or posterior thigh?

the shaft of the bone is called the DIAPHYSIS

the flared portion near the end of the bone is called the METAPHYSIS

the end of the bone near the joint surface is called the EPIPHYSIS

there is often a faint line separating the METAPHYSIS from the EPIPHYSIS that marks the prior position of the growth plate (dotted line)