12 Pharm of the Eye Flashcards
Don’t forget picture of eye anatomy in your notes.
Yay, good job looking at it.
Mydriasis is?
dilation
Miosis is?
constriction[think of cells undergoing meiosis constricting till they split in half]
Consensual pupil response assesses?
“brain damage”
What muscle does mydriasis?
-Radial smooth muscle contracts
What happens to sympa/parasympa when mydriasis occurs? (2)
-inhibit para (M3 muscarinic antagonists in iris) [strong dilation]-stimulate sympa (alpha 1 agonists in iris) [weak dilation]
What muscle does miois?
constrictor pupillae contracts
What things happen with sympa/parasympa when miosis occurs? (3)
-stimulate para (M3 muscarinic agonists in iris) [strong contract]-inhibit symmpa (alpha 1 antagonist in iris) [weak contraction]-stimulate (agonist) opioid receptor in the CNS -> “pinhole” pupil [strong contraction]
Of the things that affect refractive power, what are the 2 (of the multiple) ways we need to know?
-air:cornea interface-lens curvature
What suspends the lens?
“suspensory ligaments” (I think these are zonular fibers) attached to ciliary muscle.
When ciliary muscle contracts what happens?
Relaxation of lens -> increased radius -> see close up. (The natural state of the lens is to be round, contraction of ciliary muscle relieves the tension on the zonula fibers. This relief causes the lens to return to the natural round state)
What receptor agonist contracts the ciliary muscle?
Muscarinic agonsits (carbachol & pilocarpine?)
What is cyloplegia?
Blocked accomodation reflex. (muscarinic antagonists, ex atropine)
Atropine side?
Acute glaucoma
T/F Ciliary muscle is influenced by sympa?
F. No adrenergic receptors.
What is presbyopia?
lens loses accomodation (flexibility) w/ age[12 diopter accomodation young adult, 1 diopter by age 50]
What secretes aqueous humor?
blood vessels of ciliary body!
What path does aqueous humor take?
thru anterior chamber/pupil, drains to:-trabecular meshwork ->-canal of Schlemm ->-Episcleral vein ->-Uveoscleral outflow