The semicircular canals contain three main parts: the horizontal, posterior, and superior canals. Each of these canals provides a separate sense of directional balance. The superior canal detects head rotations on the anterior-posterior (side-to-side movement, like tilting the head toward the shoulders) axis.emicircular canals. The semicircular canals are part of the inner ear. They are lined with cilia (microscopic hairs) and filled with a liquid substance, known as endolymph.