Structures related to medial orbital wall; nerve supply to medial and inferior rectus muscles
The eye and optic nerves have been removed to display the medial rectus muscle, the superior oblique muscle and its trochlea, as well as related blood vessels and nerves. The lacrimal canaliculi(8) are cut across at the point at which they penetrate the lacrimal fascia. Short ends of muscle fibres (9) indicate the attachment of the lacrimal part of the orbicularis oculi muscle (Horner's muscle). The attachment of the medial check ligament (7) to the posterior lacrimal crest is shown, although the relation of this fascial band to the medial rectus muscle has been disturbed.
Tendon of superior oblique muscle
Supratrochlear nerve (cut off within orbit but shown here in relation to trochlea and its anastomosis with the infratrochlear nerve)
Superior oblique muscle
Infratrochlear nerve (palpebral branches visible posterior to pointer)
Dorsal nasal artery
Anterior ethmoidal nerve
Medial check ligament (attached to posterior lacrimal crest)
Lacrimal duct (cut off)
Lacrirnal part orbicularis oculi muscle (attached to lacrimal fascia)
Upper pointer: Medial wall of orbit Lower pointer: Inferior wall of orbit
Inferior rectus muscle
Inferior oblique muscle
Infraorbital sulcus
Nasociliary nerve
Superior oblique muscle
Medial rectus muscle
Position of common annular tendon (cut through)
Optic nerve (II)
Oculomotor nerve (III) (branches of inferior division of nerve enter medial and inferior rectus muscles)