(b) Source: GAS 849-852, 855; GA 450, 465, 536The right abducens nerve innervates the right lateral rectus, which mediates outward movement (abduction) of the right eye. Inward movement is accomplished by the medial rectus, supplied by the oculomotor nerve. Downward movement in the midline is accomplished by joint activation of the superior oblique and inferior rectus muscle. Downward movement of the pupil from the adducted position is a function of the superior oblique alone, which is supplied by the trochlear nerve. Down and out motion is mediated by the combined actions of the lateral rectus and inferior rectus, which are innervated by the abducens and oculomotor nerves. Downward movement of the pupil from a forward gaze is a result of combined actions of inferior rectus and superior oblique muscles, supplied by oculomotor and trochlear nerves, respectively.