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Refractive State, Motor and Sensory System
Exam I OP
37
Pharmacology
Undergraduate 2
09/13/2011

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Cards

Term
What direction do efferent signals travel?
Definition
Brain to eye
Term
What direction do afferent signals travel?
Definition
Eye to brain
Term
What are the four ophthalmic formulations that act on the ocular and autonomic system?
Definition
Adrenergic Agonists, Adrenergic Antagonists, Cholinergic Agonists, Cholinergic Antagonists
Term
What two systems make up the Autonomic Nervous system?
Definition
Sympathetic and parasympathetic nervous system
Term
What are the two branches of the Nervous system?
Definition
CNS and PNS
Term
What are the three trajectories of the 3rd order neuron trajectory of the efferent Oculosympathetic pathway?
Definition
External Carotid, Internal carotid, and middle ear. The middle ear will join the tympanic branch of of the glossopharengeal (IX) carotic-tympanic nerve. It rejoins the trajectory, goes through the cavernous sinius, ophthalmic nerve (SOF) and is the nasociliary nerve/ long ciliary nerve, dilator pupillae/ ciliary body.
Term
Where does the Effernt oculosympathetic pathway originate?
Definition
Hypothalamus (posterior and lateral nuclei)
Term
What is the NT for the efferent oculosympathitic pathway?
Definition
Acetylcholine
Term
What would happen if there was a lesion of the fibers running along the carotid artery?
Definition
Vasodilation of that side of the face and anhydrosis (the inactivation of sweat glands)
Term
What is the NT of the 2nd order neuron trajectory of the Effernt Oculosympathtic Pathway?
Definition
Acetylcholine.
Term
Which order neurons innervate the inferior and superior muller muscle and the sweat glands of the forehead?
Definition
3rd order neuron trajectory of the oculosympathtic pathway
Term
What are the three main ocular structures involved in post-ganglionic synapsis?
Definition
iris dilator muscle, iris sphincter and the ciliary body
Term
What type of receptors are in the Iris dilator muscle?
Definition
Mainly Alpha 1 receptors but also a few beta receptors.
Term
The contraction of the iris dilator muscle causes what?
Definition
Mydriasis=dilation
Term
Does the sphincter muscle respond more to the sympathetic or parasympathetic activity?
Definition
Parasympathetic (muscarinic). Very little response to sympathetic stimulation although beta receptor stimulation does cause soem degree of muscle fiver relaxation.
Term
What type of oculosympathetic receptors predominate in the ciliary body?
Definition
Beta receptors predominate.
Term
Beta receptor stimulation in the ciliary body will cause what?
Definition
an excitatory response. (increase in active secretion of aqueous humor)
Term
An Alpha receptor stimulation in the ciliary body will cause what?
Definition
Inhibitory response. (decrease in active secretion of aqueous humor)
Term
How much of the secretion of aqueous humor is an active process?
Definition
70% 30% is passive diffusion
Term
Direct sympathomimetics are also known as what?
Definition
Adrenomydriatics
Term
What do direct sympathomimetics stimulate?
Definition
post-ganglionic receptors.
Term
What is the counterpart of norepinephrine?
Definition
endogenous epinephrine
Term
What are the two types of direct sympathomimetics discussed in class?
Definition
Epinephrine and Phenylephrine
Term
Why is epinephrine not used anymore in optometry?
Definition
It causes a hypotensive effect. Tx POAG increases uveal scleral outflow.
Term
What receptors does phenylephrine effective on?
Definition
Alpha. Little or no effect on beta.
Term
What concentrations are available for Phenylephrine? and what are the uses of each?
Definition
.12% causes vasoconstriction but no dilation. 2.5% dilates and 10% is no longer used due to side effects.
Term
When dilating with phenylephrine, what condition do you need to watch out for?
Definition
Hypertension
Term
How does phenylephrine affect the dilator pupillae, arterioles, and muller's muscle?
Definition
contracts the dilator pupillae and smooth muscle of the conjunctival arterioles. Stimulates mueller's muscle thus increasing palpebral fissure
Term
Does phenylephrine cause cycloplegia?
Definition
No. (no effect sphincter muscle) sympathetic is only system involved.
Term
Cycloplegia involves what two muscles?
Definition
Dilator muscle and the sphincter muscle.
Term
What is the maximum effective concentration of Phenylephrine?
Definition
5% although there is little significant difference in 2.5% and 10% in dark eyes.
Term
What are the clinical uses for Phenylephrine?
Definition
Posterior synechiae (10%), pupillary cysts (2.5%), Horner's ptosis (.125%), Dx Horner's (1%), Conjunctival hyperemia (.125%).
Term
What ocular conditions do you have to be aware of when using phenylephrine?
Definition
Narrow angles and can have hyper reactive effect in cases of corneal abrasion. (1-1.5 mm mydrasis)
Term
What is a posterior synechiae?
Definition
it is when the posterior iris is impacted on the crystalline lens. It affects the aqueous humor movement. Caused by many things but most commonly chronic uveitis. Limits flow from posterior to anterior chamber. Phenylephrine is used to pull the sphincter muscle away from the lens.
Term
What type of drugs cause pupillary cysts?
Definition
Really strong myotics. No longer used.
Term
What are the ocular side effects of phenlephrine?
Definition
Lacrimation due to irritative effect, pain, keratitis, allergic dermatitis, iris pigment drop out, rebound miosis, decrease in conunctival and iris po2 with chronic use.
Term
What does a decrease in conjunctival and iris po2 cause? and chronic use of what drug causes this?
Definition
Vasoconstriction of conjunctival and iris vasculature. Blood flow restriction. Hypoxia. Phenylephrine
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