this is unit 13 ophthalmic and dermatologic agents your course objectives um or your unit objectives are listed here as usual and along with the associated chapter readings to associate this information to and then also know that there is a powerpoint lecture as well that is associated with this and mainly it's just a bunch of slides with some of the graphics that goes over the anatomy and physiology please make sure to have that powerpoint slide available to you or next to you so that way you can kind of flip back and forth between the lecture content and the slides to help hardwire some of that information the graphics can be helpful so review anatomy and physiology i'm going to go ahead and flip to your powerpoint slide and then just follow along in that manner so anatomy and physiology um anatomy speaking we know that the eye is a sensory organ it converts patterns of light to nerve impulses that are actually sent to the brain and then the brain interprets those impulses and makes some type of meaningful or meaning of that visual input further looking at the anatomy of the eye we have the sclera the sclera is a very tough it's a white coat of fibrous tissue that surrounds the entire eyeball except for the cornea and it helps maintain the shape of the eye and quite commonly we're going to refer to that as the white of the eye or you will hear it referred to as that we also have the musculature of the eye and this is actually um one of the photos here is actually from your textbook and so the musculature of the eye the eye is basically held in place by six muscles and they are controlled by cranial nerves you can see on the different muscles that actually hold that eye in place and allow for movement going back when we are looking at the eyelid and the eyelids are movable they can open or close and they help protect the eye when they're closed and then when they're open it allows for vision to occur we also have what's called the conjunctiva and the conjunctiva is a very clear mucous membrane it lines the inner portion of the eyelid and also covers the exposed anterior surface of the eyeball and tears the front of the eye okay anterior surface of the eyeball and it aids in providing lubrication okay so internal um internal structure of the eye so we have the cornea and the cornea is the very transparent anterior portion of the eye and that it sits in front of the lens and it basically acts as the eyes most outer lens okay it functions like a window that controls and focuses the entry of light there is no blood supply to the cornea but it receives its nourishment from tears and then aqueous humor okay so we also have the anterior chamber um that's basically that bubble like portion of the front of the eye that is between the iris and the cornea so here you have the cornea and then here you have the iris okay the lens the lens is transparent it's that transparent curved structure of the eye and it is actually located behind the iris and the pupil so this is your lens right here okay let me get rid of some of these markings um so it's located behind the iris and the people and along with the coordinate helps to refract light to be focused by the retina and then you have the iris and the iris so this is your iris here okay um you take that marking away so the iris is basically this round muscular portion of the eye and it gives the eye its color and it also controls the amount of light that passes through the pupil how does it do that it's a very uh you think of it as like a muscular curtain so it can actually constrict or dilate so that's the manner in which it controls the amount of light that passes through the pupil okay so it constricts or dilates you have the posterior chamber and cavity right that's the back portion of the eye posterior chamber and it's filled with a watery fluid known as vitreous humor so aqueous passes into that posterior chamber and then it flows forward through the pupil into the anterior chamber of the eye okay so this is our vitreous humor that's in the back of the eye right here see this is the line you have here this is all vitreous humor right and then it's going to flow um outward and drain forward through the people into that anterior chamber of the eye so we have the optic nerve the optic nerve is a major nerve that connects the posterior end of each eye to the brain to which it transmits visual signals and this aids in interpreting incoming visual stimuli and then you have the retina that is the innermost layer of the eye it contains both rods black and white vision and cones which is color vision okay so your rods are responsible for that black and white vision cones are responsible for color vision um so it seems that receives that visual stimuli and that basically transmits them to the optic nerve and then we also have the central retinal artery and vein the artery carries blood into the eye and supplies nutrition to the retina and then the vein carries blood out of the retina so this is all just some basic amp just to remind you hopefully all of this is review though okay so physiology speaking so now we're on a fluid so we have blood flow and that blood flow some of this is going to be a little bit of reiteration of what was already mentioned so we have blood flow through that central artery and vein that carries blood into the eye and supplies nutrition to the retina and carries blood away from the retina so we also have the vitreous humor we already kind of talked about that that's the fluid that actually fills the posterior chamber of the eye and then your aqueous humor is the fluid that fills the anterior chamber of the eye and both of those actually contribute to intraocular pressure that is the pressure that is within the eye we also have our tears or lacrimal glands let me just flip here really quick so we have um these lacrimal glands and their glands are located at the medial corner of the eyelids that produce tears and we also have ducts and we have what's called nasal lacrimal ducts and these are the small tubes that actually drain the tears from the lacrimal glands into the nasal cavity okay so this is why and we're going to go over eye drops and how to properly instill eye drops and this is why we actually as one of the steps in inserting eye drops we actually take our finger or we tell our patient instruct them to take their finger if they're doing eye drops at home and we apply pressure to the corner of the eye here after we install those eye drops so why do we do that this aids in preventing systemic absorption of the drug so the drug therefore stays within the eye and doesn't drain into that nasal lacrimal duct okay we want it to stay in the eye and do its job here and not drain through this duct here so that's why we should be actually applying pressure to the eye whenever we give eye drops after we administer them um so for vision go back here we already talked about rods rods is your black and white and peripheral vision and then the cones are your color and straight ahead vision so that's what those are responsible for muscle movement we've already looked at we already looked at the figure that's actually on page 881 if you wanted to review it but just remember again the eyes held in place by those six muscles and they're controlled by the cranial nerves and then our nervous system our nervous system our nervous tissue in the retina is connected to the brain through the optic nerve