Cranial Nerves
3rd Edition

Trochlear IV

Description Labelled Unlabelled
Figure IV–1 A, Apex of the right orbit illustrating the tendinous ring. B, Dorsal aspect of the brain stem. C, Somatic motor tracts from the trochlear nuclei in the brain stem to the superior oblique muscles.
Somatic motor efferent (pink)
Figure IV–2 Slice through the right cavernous sinus showing the relationship of CN IV to other structures coursing through the sinus.
Somatic motor efferent (pink)
Figure IV–3 Movements of the right eye produced by the action of the superior oblique muscle in different eye positions (viewed from above). For rotation around axes, see Figure IV–4.
Figure IV–4 Right eye movements around the “X,” “Y,” and “Z” axes. Movements driven by CN IV are highlighted in pink.
Figure IV–5 Ocular rotation. A, Before infarction of CN IV; B, after infarction of CN IV.
Figure IV-6 Lakshmi is unable to move her right eye downward when her right eye is adducted.