In what order are these structures organized from most superficial to deepest: longissimus, rhomboids, rotatores, trapezius, serratus posterior superior?

The correct sequence organizes the mentioned anatomical structures from most superficial to deepest: trapezius, rhomboids, serratus posterior superior, longissimus, and rotatores.

The trapezius is the most superficial muscle found on the upper back and is responsible for a variety of movements, including scapular elevation and rotation. Just beneath the trapezius lie the rhomboids, which are positioned to connect the spine with the scapula, playing a critical role in retracting the scapula.

Following the rhomboids, the serratus posterior superior is located deeper still, originating from the upper spine and attaching to the ribs. This muscle aids in the mechanics of breathing by elevating the ribs.

Next in depth is the longissimus, a part of the erector spinae group that runs along the length of the spine, extending from the lumbar region to the cervical region. This muscle provides support for extending the back.

Finally, the rotatores occupy the deepest layer among these muscles. These small muscles are primarily functionally involved in the rotation and stabilization of the spine in various movements.

This hierarchical order illustrates the relationship between these muscle structures in terms of their anatomical location relative to the surface of the body and highlights