Autonomics Of Eye

Question 1

Phenylepherine

Answer 1

Alpha 1 adrenergic stimulant used topically to dialate pupil. a1 agonist

Question 2

Epinepherine

Answer 2

Nonspecific for a and beta receptors. In the eye it is used as an a1 agonist to prmote eye dilation for the treatment of glaucoma.

Question 3

Nicotine

Answer 3

Activates nicotinic receptor activating parasympathetics to produce miosis.

Question 4

Cocaine

Answer 4

Dilates eyes if sympathetics are working. It prevents the reuptake of NE, but NE must be released naturally by the cell. No effect indicates sympathetic dysfunction. It is a good test to see if the nerves are working. If absence of a pupillary dilation indicates horner syndrome.

Question 5

Amphetamine

Answer 5

Will dilate eye if postganglionic nerve is present and contains NE. It acts by reversing the axoplasmic pump. Response to amphetamine indicates normal postganglionic nerve. Absence of a response to cocaine and positive response to amphetamine means preganglionic horner syndrome.

Question 6

Pilocarpine

Answer 6

Muscarinic agonist leading to parasympathetic activation and pupilary constriction and enhances aqueous humor drainage through trabecular meshwork and canal of schlemm. if it is ineffective, then teh defect must be in the eye.

Question 7

Phyostigimine

Answer 7

Prevents ACH degredation leading to muscarinic agonism and pupillary constriciton

Question 8

Ecothiophate

Answer 8

Prevents ACH degredation leading to muscarinic agonism and pupillary constriciton

Question 9

Terazosin

Answer 9

a1 receptor antagonist. It is not used in the eye but can have its effects there

Question 10

Reserpine

Answer 10

a1 antagonist. Acts by depleting NE

Question 11

alpha 1 receptor

Answer 11

activation leads to vasoconstriction and pupillary dilation

Question 12

Timolol

Answer 12

Beta blocker that decreases aqueous humor formation to treat glaucoma

Question 13

Latanoprost

Answer 13

Prostaglandin derivative which increases uveo-scleral outflow of aqueous humor.

Question 14

Acetazolamide

Answer 14

Carbonic anhydrase inhibitor which reduces the amount of bicarbonate made which cannot be exchanged for Na and Cl. This prevents a large osmotic difference and lowers pressure in the eye

Question 15

Atropine

Answer 15

Muscarinic antagonist which inhibits the parasympathetic nervous system leading to pupilary dilation.

Question 16

Mydriasis

Answer 16

Term for dilation of the pupil