anatomy of the eyeball

Question 1

what covers the iris?

Answer 1

cornea

Question 2

where is the lacrimal gland located?

Answer 2

beneath the eyebrow

Question 3

what is the anatomical name for the tear duct?

Answer 3

lacrimal lake

Question 4

what covers the sclera?

Answer 4

conjunctiva

Question 5

what forms the deepest layer of the eyelid?

Answer 5

palpebral conjunctiva

Question 6

what is the conjunctiva?

Answer 6

thin mucous membrane that is reflected onto sclera of the eyeball (bulbar conjunctiva)

Question 7

what does the fibrous layer consist of?

Answer 7

sclera and cornea

Question 8

what does the sclera provide?

Answer 8

attachment for the extraocular muscles

Question 9

what is light entering the eye partially refracted by?

Answer 9

cornea

Question 10

what does the uvea consist of?

Answer 10

iris
ciliary body
choroid

Question 11

what is the iris?

Answer 11

pigmented membrane with a central opening (pupil) which adjusts in size in response to light

Question 12

what does the pupil do?

Answer 12

regulate the amount of light that reaches the retina

Question 13

what is the diameter of the pupil altered by?

Answer 13

smooth muscle fibres within the iris, innervated by autonomic nervous system

Question 14

what does the ciliary body do?

Answer 14

adapt the shape of the lens, anchors lens and produce aqueous humor

Question 15

what are the 2 parts of the ciliary body?

Answer 15

ciliary muscle and ciliary processes

Question 16

what does the ciliary muscle consist of?

Answer 16

collection of smooth muscle fibres which are attached to lens of the eye by the ciliary processes

Question 17

what is the choroid?

Answer 17

layer of connective tissue and blood vessels which provide nutrition and gas exchange to outer layers of the retina

Question 18

what is the fundus of the eye?

Answer 18

the inferior surface opposite the lens which light is focused

Question 19

what does the fundus consist of?

Answer 19

retina
optic disc
macula
fovea
posterior pole

Question 20

what is the retina?

Answer 20

light detecting component of the eye

Question 21

what are the 4 main layers of the retina?

Answer 21

retinal pigment epithelium
rods and cones
bipolar neurons
ganglion neurons

Question 22

what do axons of ganglion neurons form?

Answer 22

optic nerve

Question 23

where do the retinal veins and arteries lie?

Answer 23

anterior to retina

Question 24

why is the optic disc called the “blind spot”?

Answer 24

no photoreceptors

Question 25

what forms the optic disc?

Answer 25

axons of ganglion cells that leave eye to form optic nerve (CN II)

Question 26

what is the only point of entry/exit for blood vessels and axons of optic nerve (CN II)?

Answer 26

optic disc

Question 27

which part of the retina contains the greatest density of cones?

Answer 27

macula

Question 28

what is the fovea responsible for?

Answer 28

high acuity vision

Question 29

what does complete interruption of retinal artery branch/retinal vein indicate?

Answer 29

loss of field of vision at area of ischaemia (nasal or temporal)

Question 30

what does complete interruption of flow of the central artery (end artery) or vein indicate?

Answer 30

monocular blindness

Question 31

what are the two segments?

Answer 31

anterior posterior

Question 32

where is the anterior chamber?

Answer 32

in front of lens

Question 33

what is the anterior segment divided into?

Answer 33

anterior chamber posterior chamber

Question 34

where is the anterior chamber located?

Answer 34

between cornea and iris

Question 35

where is the posterior chamber located?

Answer 35

between iris and suspensory ligaments

Question 36

what is the anterior chambers filled with?

Answer 36

aqueous humor

Question 37

what is the role of aqueous humor?

Answer 37

nourished and protects eye

Question 38

where is the posterior segment?

Answer 38

behind lens, 2/3 of eye

Question 39

what does the posterior segment contain?

Answer 39

vitrous body which has vitreous humor

Question 40

what is viterous humor a common location for?

Answer 40

"floaters"

Question 41

what do ciliary processes secrete?

Answer 41

aqueous

Question 42

what are the steps of circulation of aqueous in anterior segment?

Answer 42

1. ciliary body - SM and BV, ciliary processes secrete aqueous 2. aqueous circulates within post chamber to nourish lens 3. aqueous passes through pupil into anterior chamber to nourish cornea 4. aqueous reabsorbed into scleral venous sinus (Canal of Schlemm) at iridocorneal angle

Question 43

what can raised intra-ocular pressure cause?

Answer 43

ischaemia of retina glaucoma

Question 44

what is a cataract?

Answer 44

clouding of lens

Question 45

what is another word for corneoscleral junction?

Answer 45

limbus

Question 46

where does the eyeball receive arterial blood supply from?

Answer 46

ophthalmic artery

Question 47

what is the ophthalmic artery a branch of?

Answer 47

internal carotid artery

Question 48

what artery supplies some of the structures in the floor of the orbit?

Answer 48

infraorbital artery

Question 49

what is the infraorbital artery a branch of?

Answer 49

external carotid artery

Question 50

what artery supplies the internal surface of the retina?

Answer 50

central artery of retina

Question 51

what would occlusion of the central artery cause and why does this occur?

Answer 51

blindness as it's an end artery

Question 52

what is venous drainage of the eyeball carried out by?

Answer 52

superior and inferior ophthalmic veins

Question 53

where do the superior and inferior ophthalmic veins drain into?

Answer 53

cavernous sinus via superior orbital fissure

Question 54

what is the only vein that drains the retina?

Answer 54

central vein of retina

Question 55

in the danger triangle it is possible that infection from this area can spread to the brain, why is this?

Answer 55

because of venous communication between facial vein and cavernous sinus via ophthalmic veins

Question 56

when light from objects in the left visual field, which does it hit on the left and right eye?

Answer 56

left - nasal retina right - temporal retina

Question 57

when light from objects in the right visual field, which does it hit on the left and right eye?

Answer 57

right - nasal retina left - temporal retina

Question 58

what transmits neurochemical signals from retina to visual centres in brain?

Answer 58

nerve fibres in optic nerve

Question 59

where do nerve fibres from the nasal retina cross to opposite sides of the brain?

Answer 59

optic chiasm

Question 60

where is light from the left visual field processed?

Answer 60

right primary visual cortex