EXTRAOCULAR MUSCLES



There are seven voluntary (somatic innervation) and at least three involuntary (sympathetic innervation) muscles.

 Voluntary muscles are:

  • Four recti: Superior rectus, inferior rectus, medical rectus, lateral rectus.
  • Two oblique: Superior oblique and inferior oblique
  • One levator: Levator palpebra superioris

Recti muscles arise from common annular tendon (tendinous ring).

 Nerve supply

  • So4: Fourth cranial nerve for superior oblique.
  • Lr6: Sixth cranial nerve for lateral rectus. The remaining are supplied by 3rd cranial is oculomotor nerve.
  • Paralysis of lateral rectus-medial squint
  • Lesion of 3rd oculomotor nerve-lateral quint
  • Lesion of 4th cranial (trochlear)-diplopia