Ocular Anatomy and Physiology Lecture Powerpoint

Question 1

Orbit

Answer 1

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

Question 2

4 walls of the orbit

Answer 2

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

Question 3

LR6SO4

Answer 3

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)

Question 4

4 layers of the eyelid

Answer 4

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

Question 5

2 eyelid retractor muscles

Answer 5

• 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

Question 6

Orbital septum

Answer 6

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

Question 7

Lacrimal gland

Answer 7

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

Question 8

Lacrimal drainage and percentages

Answer 8

20% from the upper punctum

80% from the lower punctum

Question 9

Conjunctiva

Answer 9

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

Question 10

Sclera

Answer 10

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)

Question 11

Cornea

Answer 11

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

Question 12

Anterior chamber

Answer 12

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

Question 13

Uveal tract

Answer 13

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

Question 14

Iris

Answer 14

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

Question 15

Ciliary body

Answer 15

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

Question 16

Lens

Answer 16

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

Question 17

Accommodation

Answer 17

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)

Question 18

Vitreous humor

Answer 18

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

Question 19

Vitreous detachment

Answer 19

Causes floaters

Question 20

Retina

Answer 20

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

Question 21

Macula

Answer 21

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

Question 22

Fovea

Answer 22

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

Question 23

Optic disc

Answer 23

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

Question 24

Scotomas

Answer 24

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