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