Which term describes the process of straightening a body part?

The term that describes the process of straightening a body part is extension. When a joint is extended, the angle between the bones that form the joint increases, effectively allowing the body part to move away from a flexed position. This movement is commonly observed when straightening the arm at the elbow or the leg at the knee, where the body part transitions from a bent position back to a straight alignment.

In contrast, flexion refers to the bending of a joint, which decreases the angle between the bones. Abduction involves moving a body part away from the midline of the body, while adduction is the movement of a body part toward the midline. These terms describe movements that are distinct from the action of straightening a body part and highlight different directional motions within the anatomy.