Final answer:
There are six extrinsic eye muscles attached to the exterior surface of each eyeball, facilitating various eye movements.
Step-by-step explanation:
Each eyeball is controlled by six extrinsic eye muscles that originate outside of the eye and are attached to the exterior surface of the eyeball. These muscles facilitate the movement of the eye in various directions. The extraocular muscles include four rectus muscles (superior, inferior, medial, and lateral) and two oblique muscles (superior and inferior).
The extraocular muscles are innervated by three cranial nerves: the abducens nerve for the lateral rectus, the trochlear nerve for the superior oblique, and the oculomotor nerve for the rest of the muscles. The motor nuclei of these nerves are connected to the brain stem, which coordinates rapid and precise eye movements, crucial for tasks such as reading and scanning faces.