Anatomy of the eye

Question 1

3 layers of eyeball

Answer 1

Fibrous (collagen, complete coat)
Vscular
Sensoary

Question 2

Whchh nerve of the eyeball?

Answer 2

Optic nerve (cranial nerve II)

Question 3

2 parts of the fibrous coat

Answer 3

-Sclera (opaque, attatchment for eye muscles)
-Cornea (opaque - fibres in the same direction and is transparrent)

Question 4

3 parts of the vascular part

Answer 4

-iris (changes the amount of light let through),
-ciliary body (secretes aqueous humor and suspends the lens)
-Choroid ( supplies blood to the outer layers of the retina)

Question 5

why is cornea transparent?

Answer 5

Because all the collagen fibres are alligned in the same direction, to let light through)

Question 6

What is the retina?

Answer 6

the sensory section of the eye, contains light sensitive rods and cones that allow us to see

Question 7

Post vs anterior segment and filled with

Answer 7

Posterior segment is veerything behind the lens, flled with vitreous Humor (VH)

Anterior segment is everything infront of the lens and filled with aqueous humor (AH)

Question 8

What are zonules

Answer 8

the very thin strings attaching the lens to the ciliary muscle

Question 9

Anterior vs posterior chamber of the anterior segment of the eye

Answer 9

anterior chamber is the section in front of the iris
post. chamber is infront of the lens but behind the iris

Question 10

What is the angle of the anterior chamber

Answer 10

the angle around the iris to Schlemms canal (where all the aqueous humor drains) on the sclera/cornea junctiony kinda

Question 11

What is the pathway of the aqeous humour

Answer 11

from the cliary body (where it’s produced) around the iris and drains in Schlemm’s canal

Question 12

How many bones make up the orbit? WHich bones are they?

Answer 12

7
Frntal,
zygomatic,
maxillary
(pallatine)
Sphlenoid
lacrimal
ethmoid

Question 13

What are the foramen of the eye?

Answer 13

OPtic foramen
Superior Orbital fissure
Inferior Orbital fissue

Question 14

Why are the inferior and medial orbital walls weaker?

Answer 14

Because of the sinuses

Question 15

AP legth of eyeball/AP length of orbit

Answer 15

eyeball = 24mm
Orbit = 40mm

Question 16

What is the role of the fat?

Answer 16

cushions and protects

Question 17

2 conditions that affect the fat on th eeyeball

Answer 17

Starvation - last fat to go so sunken eyeballs menas that theyre at a late stage

Thyroid eye disorder - staring like look, too much fat

Question 18

WHat is the conjunctiva?

Answer 18

mucous membrane undreneath the eyelid, loops back over to the sclera but doesn’t cover the cornea

Question 19

What is the tarsal plate? What mebibomian glands do what?

Answer 19

Hard plat in the eyelid that helps the eye to keep its shape and contains the Meibomian glands which secrete oily substance which helps the tear film not to dry out

Question 20

WHere is the fornix?

Answer 20

It is the mucous membrane (conjunctva) at the part it turns back on itself

Question 21

Does he conjunctiva cover the cornea?

Answer 21

NO!!!

Question 22

What does the lacrimal gland do?

Answer 22

Secretes tears/fluid over the eye to lubricate

Question 23

Extrinsic vs intrinsic muscles of the eye

Answer 23

Extrinsic muscles - on the outside of the eye and help with eye movement

Intrinsic muscles - within and help change lens shape etc

Question 24

What are the 3 intrinsic muscles of the eye? What do they do?

Answer 24

Cilliaris - focusses on near objects)
Constrictor - circular muscle , constricts
Dilator - dilates duh

If it begins with C, its cranial nerve 3 (parasympathetic innervation)

Dilator supplied by sympathetic plexuss (around the blood vessels)

Question 25

What are the 6 extrinsic ocular muscles? (4 and 2)

Answer 25

4 retus's (straigh muscles) Superior rectus, inferiot rectus, lateral rectus and medial rectus. 2 oblique - superior and inferior

Question 26

What does the lps do?

Answer 26

levator palpable superioris - opens the eyelid. Orbicularis oculi closes the eye

Question 27

Innervation of the muscles of the eye

Answer 27

Superior orbital = trochlea (the superior orbital has a trochlear (pully thing) Lateral rectus = an abductor = Abducent nerve Everything else = Oculomotor (III) nerve

Question 28

4 cranial nerve that go to the orbit

Answer 28

trochlear (IV) abducent (VI) oculomotor (III) optic (II)

Question 29

Entry of cranial nerves in the orbit

Answer 29

Optic (II) = Optic foramen Superior orbital fissure = Abducent (VI), Trochlear (IV) and Oculomotor (III)

Question 30

General sensory nerve of the face

Answer 30

Trigeminal

Question 31

How does CN V 1 and V2 into the ee

Answer 31

V1 is sensory above, V2 is sensory below

Question 32

Arterial supply of the orbit

Answer 32

Opthalmic artery (banch of internal carotid)

Question 33

Central retinal artery - enters where? Branch of what?

Answer 33

2nd branch of opthalmic artery, enters with the optic nerve

Question 34

Branches 3,4,5 do what?

Answer 34

Supply the outer retina (post. part of Choroid)

Question 35

branch 6 - lomh posterorior artery supplies what?

Answer 35

anterior choroid, ciliary body and iris

Question 36

7,8 what about 9

Answer 36

7,8 are the anterior and posterior ethmoidal arteries 9 = muscular arteries

Question 37

What are the supplies of the inner and outer retinas

Answer 37

inner retina = 2nd branch (central retinal artery) outer retina = short posterior ciliary arteries

Question 38

qudrants of the retina

Answer 38

Nasal and temporal superior and inferior around the optic blind spot (where the optic nerve comes in)

Question 39

What are thicker on a fundus picture, arteries or veins?

Answer 39

veins (more blood in)

Question 40

Venous drainage of the eye

Answer 40

Superior and inferior opthalmic veins drain into the cavernous sinus

Question 41

What does the eye drvelop from?

Answer 41

ectoderm (Neural tube)

Question 42

What froms the optic vesicles?

Answer 42

from dienecephalic part of neural tube

Question 43

What thickens to form the lens placode? What does the that then form?

Answer 43

Optic vesicles thicken to fromt he lens placode, which then push in to form the optic cup

Question 44

What is formed from the a)Surface ectoderm b) Mesenchyme and c) Les fibres

Answer 44

a) eyelids, conjunctiva, corneal epithelium b) choroid, stroma or cornea, sclera and extraocular muscles c) epithelium of lens vesicle and later loose their nuclei