Posted by esb on October 10, 2011 at 16:59:45:
In Reply to: Orbit and Globe - Part II posted by lae2 on October 10, 2011 at 14:22:34:
: Orbit and Globe - Learning Objectives and Review Questions
: True/False
: True/False - October 08, 2011 - Dr. Quillen
: 1. The lens provides 66% of the refractive index of the globe and the cornea provides 33%.
F - cornea provides ~2/3
: 2. The orbital septum separates the region of the face from the orbit.
T? - extends around around the orbital rim and separates eyelid tissues from the orbit
: 3. The upper medial superior conjunctival fornix receives tears from the ducts of the lacrimal gland.
F - lateral superior conjunctival fornix?
: 4. The eyelids play a critical role in protecting the eye.
T
: 5. The meibomian glands secrete tears in response to irritation and the lacrimal gland secretes tears to assure lubrication.
F - lacrimal gland secretes tears in response to irritation
: 6. The meibomian glands are also known as the tarsal glands.
T
: 7. The lacrimal gland is mostly involved with reflexive tearing and the accessory lacrimal glands are primarily responsible for tear film.
T
: 8. The vascular tone of the conjunctiva, if low, leads to conjunctival injection (red eye).
T? - since this would be synonymous w/ blood vessel dilation?
: 9. Loss of sympathetic tone to the orbit is a cause of conjunctival injection.
T? - See above?
: 10. Conjunctival injection is a symptom of Horner's syndrome.
T
: 11. Total refraction of the eye is 1/3 by cornea and 2/3 by lens.
F - flip the proportions. Isn't this the same as Q1?
: 12. Flattening the cornea changes the refractive properties of the eye.
T - yay Lasik!
: 13. The corneal arterial plexus is derived from the lacrimal artery.
T? - is this refers to the anastemosing conjunctival arteries around the rim of the cornea. There's also an annular nerve plexus that innervates the cornea itself, derived from the ciliary nerves.
: 14. End arteries feed the cornea and blockage of these arteries leads to corneal necrosis.
T? - I'd assume blockage of the blood supply could lead to necrosis, but the more common mechanisms for corneal ulceration are bacterial
: 15. The pain of corneal abrasions is minor because the neural supply to the cornea is slight.
AHAHAHAHAHAHA...I wish. False.
: 16. The primary sensory cell bodies that mediate corneal pain are located in the geniculate ganglion.
F?