Posted by CB on October 11, 2011 at 19:02:05:
In Reply to: Orbit - Part III posted by lae2 on October 11, 2011 at 08:54:05:
: True/False - October 10, 2011 - Dr. Wilkinson
: The questions were not submitted by the lecturer
: 1. Dura provides protection for the subarachnoid space from orbital fractures. True.
: 2. Both the inferior and superior divisions of the oculomotor nerve pass through the annulus tendineus. True.
: 3. The trochlear nerve passes through the inferior orbital fissure and outside of the annulus tendineus. False- superior.
: 4. Of the seven skeletal orbital muscles, only one takes origin from the anterior aspect of the orbit. True- inferior oblique.
: 5. The facial arterial tree participates in an arterial anastomosis between the external and internal carotid arterial trees. True- internal via the supratrochlear artery and angular arteries.
: 6. Posterior venous drainage of the orbit is into the cavernous sinus. True. Superior opthalmic drains.
: 7. Infections of the eyelids run the risk of intracranial infections. True.
: 8. Pulsatile exophthalmos may reflect an arteriovenous shunt within the cavernous sinus. True.
: 9. The cavernous sinus is complex. True- as of today. Maybe not so bad after Sarah's lecture.
: 10. Oculomotor nerve palsy causes the resting position of the globe to be abducted. True- lateral rectus is quite strong apparently. Also, blown pupil and constricted blood vessels.
: 11. Abducens nerve palsy caused the resting position of the eye to be adducted. True, medial recctus takes over.
: 12. Oculomotor nerve palsy causes frank ptosis but some elevation of the superior lid is possible. True- superior tarsal muscle.
: 13. Emotional crying and irritant crying both involve the primary lacrimal gland but emotional crying, unlike irritant crying, does not involve the trigeminal nerve. True. GSA from V1 would mediate irritant crying.
: 14. The nasolacrimal duct empties into the inferior nasal meatus. True.
: 15. The superior margin of the lacrimal sac is superior and posterior to the medial palpebral ligament. True.
: 16. A fracture of the orbital floor may cause dryness of the maxillary sinus but spare lacrimation. False? Orbital floor contains zygomatic nerve carrying post-ganglionic parasympethics to the lacrimal gland.