Which muscle is not considered one of the six extraocular muscles?

The levator palpebrae is indeed not considered one of the six extraocular muscles. The primary function of the extraocular muscles is to control the movements of the eyeball, allowing for various visual directions. These six muscles include the superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, and inferior oblique, all of which are responsible for moving the eye in different directions.

In contrast, the levator palpebrae primarily functions to elevate the upper eyelid, rather than directly moving the eyeball. This distinction is crucial for understanding ocular anatomy and muscular function. Hence, while the levator palpebrae plays an important role related to the eye, it does not fall into the category of muscles directly responsible for eye movement.