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T/F Autonomic Innervation of the Orbit

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Posted by Ichneumia Rapidae on December 06, 2014 at 13:50:54:

1. The lacrimal gland is reflexive to trigeminal nerve mediated irritation whereas the accessory lacrimal glands provide continuous lubrication to the globe. TRUE

2. The cell bodies that mediate the afferent limb of the corneal blink reflex are located in the (oculomotor nucleus). FALSE?, trigeminal ganglion? Is the question asking where the cell bodies of the afferent nerves that pick up the reflex stimulus in the first place, or the effector nuclei, in which case would be the facial motor nucleus in the brainstem (SVE to Zanzibar - palpebral part of orbicularis oculi?)

3. A lesion of the cervical sympathetic trunk is expected to cause (mydriasis). FALSE, mild ptosis

4. A lesion of the inferior division of the oculomotor is expected to cause miosis. FALSE, mydriasis

5. A lesion of the superior division of the oculomotor nerve is expected to leave the globe in an elevated position. FALSE, depressed

6. The site of the preganglionic cell bodies that mediate accommodation is the Edinger-Westphal nucleus. TRUE, proximal accommodation.

7. The site of the postganglionic cell bodies that mediate accommodation is the (pterygopalatine) ganglion. FALSE, ciliary

8. A lesion of the greater superficial petrosal nerve at the lacerate foramen may cause excessive tearing. FALSE, decreased tearing, what would cause excessive tearing?!

9. The ciliary ganglion is a sympathetic ganglion. Nevertheless, parasympathetic fibers pass through the ganglion without synapsing. FALSE, reverse

10. A lesion of the internal carotid nerve is expected to cause unilateral mydriasis. FALSE, miosis

11. A tumor at the apex of the lung is expected to cause unilateral pupil constriction. TRUE, if it disrupts the sympathetic chain on that side.

12. A cavernous sinus infection is expected to cause unilateral pupil constriction given that the inferior division of the oculomotor nerve remains healthy. TRUE

13. A mild ptosis in a young person is apt to be caused by an autonomic disturbance whereas a frank ptosis is caused by a somatic disturbance. TRUE? Superior tarsal muscle (of Muller) <- sympathetic innervation vs levator palpebrae superioris m. <- GSE oculomotor?

14. Sneezing while looking at bright light is thought to be, in part, mediated by the trigeminal nerve and not the optic nerve. TRUE? (source: lab chat)

15. The short ciliary nerves host postganglionic parasympathetic fibers and postganglionic sympathetic fibers. TRUE, also GSA fibers

16. The motor root (parasympathetic root) of the ciliary ganglion is derived from the inferior division of the oculomotor nerve. TRUE, GSE preganglionic fibers

17. The infraorbital nerve, while in the infraorbital canal, carries postganglionic parasympathetic fibers destined for the lacrimal gland. FALSE? I think that the communicating branch between the maxillary distribution and lacrimal nerve occurs more posteriorly than at the infraorbital canal (bone bound). More likely, the zygomatictemporal branch of zygomatic nerve transmits GVE from pterygopalatine ganglion to distal portion of lacrimal nerve. (Source: Mongoose Logic).

18. The zygomaticotemporal nerve leaves the orbit superior the the exit of the zygomaticofacial nerve. TRUE

19. A lesion of the (lesser superficial) petrosal nerve is expected to cause a mild ptosis. FALSE, deep, A lesion of the LSPN would cause loss of parotid gland secretion on that side of the lesion.

20. The lacrimal nerve proper is GSA only and thus does not mediate lacrimation. TRUE, native fibers of lacrimal nerve don't mediate lacrimation.

21. Traveling along with the distal parts of the lacrimal nerve are postganglionic parasympathetic fibers whose cell bodies are located in the pterygopalatine ganglion. TRUE

22. The sympathetic root of the ciliary ganglion travels through the cavernous sinus before entering the orbit. TRUE, it comes off of the internal carotid plexus on the carotid siphon, a content of the cavernous sinus.

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