In human anatomy, what action is described by the term adduction?

Adduction refers specifically to the movement of a limb or body part toward the midline of the body. This terminology is commonly used in anatomy to describe how body parts move in relation to the body's central axis. For instance, when you bring your arms down to your sides after extending them outwards, that action is classified as adduction. This concept is crucial in understanding the mechanics of movement and is often contrasted with abduction, which involves moving a limb away from the midline. The other terms in the options describe different types of movements; for example, movement away from the midline is referred to as abduction, circular motion pertains to rotation, and movement along a straight path does not specifically describe any angular relationship with respect to the midline. Thus, adduction is correctly understood as movement towards the midline, making it the accurate response.