Ocular Anatomy and Physiology Lecture Powerpoint Flashcards Preview

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Flashcards in Ocular Anatomy and Physiology Lecture Powerpoint Deck (24):
1

Orbit

Bony cavity that houses eye and surrounding tissues, composed of 4 walls and housing the nerves, blood vessels, lacrimal glands, and extraocular muscles

2

4 walls of the orbit

Roof, lateral wall (strongest), medial wall, and floor

3

LR6SO4

Refers to how lateral rectus muscle is innervated by abducens (CN VI) and superior oblique is innervated by abducens (CN IV), with the rest of them being innervated by CN III (oculomotor)

4

4 layers of the eyelid

-skin
-orbicularis oculi muscle (closes eyelid and innervated by facial nerve CN VII)
-tarsal plate (contains meibomian glands)
-conjunctiva

5

2 eyelid retractor muscles

-levator palpebrae superioris (CN III) provides majority of lift
-mueller's muscle (superior tarsal muscle) smooth muscle innervated by sympathetic fibers and not much lift is provided

6

Orbital septum

Important landmark because anterior infection to it is not as serious as one posterior to it

7

Lacrimal gland

Located superior and lateral in the anterior portion of the orbit and produces tears to lubricate the cornea and conjunctiva

8

Lacrimal drainage and percentages

20% from the upper punctum
80% from the lower punctum

9

Conjunctiva

Clear mucus membrane that covers sclera (bulbar) and posterior surface of the eyelids (palpebral) that creates a complete seal preventing it from traveling beyond the fornix, houses a lot of blood vessels

10

Sclera

Tough outer part of globe forming white part of eye, varries in thickness with thinnest portion at the limbus (junction between cornea and sclera and site where most likely to injure)

11

Cornea

Transparent avascular collagen that has the greatest focusing power of the eye, richly innervated by ophthalmic division of CN V (trigem), made of same tissue type as the conjunctiva

12

Anterior chamber

Space between the cornea and the iris, filled with aqueous humor produced by ciliary body that flows out to the front of the lens to the anterior chamber draining into schlemm's canal

13

Uveal tract

Middle layer of eye that houses 3 components from anterior to posterior being iris, ciliary body, and choroid

14

Iris

Colored part of eye that is a thin contractile pigmented diaphragm, allows light to enter eye and stimulate the retina and contains 2 muscles being the sphincter pupillae muscles that contract to constrict pupils and are innervated by parasympathetic fibers on CN III, and dilator muscles which result in dilation and are sympathetically innervated

15

Ciliary body

Posterior to iris and connects to the suspensory ligament of the lens (called a zonule), produces aqueous humor to nourish cornea and drain out thru trabecular meshwork, contraction of ciliary body allows for accommodation, provides blood supply to the outer retina

16

Lens

Biconvex, avascular transparent tissue 2nd most powerful refractive tissue, attaches to ciliary body via the zonule, opacification of lens is called cataracts

17

Accommodation

Ability of eye to focus at various distances by changing lens shape, loss begins at age 40's and results in presbyopia (diminished ability to focus)

18

Vitreous humor

Clear gelatanous avascular structure that fills space between lens and retina and is mostly composed of water and hyaluronic acid, firmly adherant to the optic disc, blood vessels, and anterior most portion of retina

19

Vitreous detachment

Causes floaters

20

Retina

Innermost layer of eye, supplied by central retinal artery, thin transparent neurovascular tissue that transmits info to the optic nerve

21

Macula

Area between the superior and inferior temporal vascular arcades where majority of cone cells are to allow for color vision

22

Fovea

Center of macula responsible for sharp focus vision, contains only cone cell receptors responsible for color vision

23

Optic disc

Most anterior portion of optic nerve, area where central retinal artery and vein enter the eye and divide into vascular arcades, enlarged in glaucoma, surrounded by meninges and bathed in CSF, transmits visula info from the retina to the brain, leaves orbit via optic canal

24

Scotomas

Areas of decreased or absent vision, often due to lesions of different pathways