The Eye

Question 1

Fibrous layer of the eye (2)

Vascular layer of the eye (3)

Inner layer of the eye (1)

Answer 1

Fibrous layer of the eye - sclera, cornea

Vascular layer of the eye - choroid, ciliary body, iris

Inner layer of the eye - retina

Question 2

Palpebral conjuntiva

Answer 2

Lines the innermost part of eyelids (lift up eyelid to see)

Question 3

Bulbar (ocular) conjunctiva

Answer 3

Lines outmost part of eyeball.

Question 4

Function and innervation of superior tarsal m.

Answer 4

Helps to raise eyelid (upper eyelid) and innervated by SNS.

Question 5

Function and innervation of orbicularis oculi m.

Answer 5

Closes eyelids and innervated by CN III.

Question 6

Complete ptosis

Answer 6

Loss of function of LPS m. from GSE fibers of CN III.

Question 7

Partial ptosis

Answer 7

Loss of function of tarsal m. from postganglionic sympathetic fibers from T1.

Question 8

Miosis

Answer 8

Pupillary constrcition from paralysis of dilator pupillae m.

Question 9

Papilledema cause:

Answer 9

Increased intracranial pressure (ICP)

Question 10

Blood supply to the eye

Answer 10

Ophthalmic a. (from ICA) gives short posterior ciliary as.
A posterior ciliary a. enters CN II and the eyeball and is called central retinal a.
Ophthalmic also gives long posterior ciliary as. and a lacrimal a.

Also: ophthalmic a. gives ethmoidal as., dorsal nasal a., supratrochlear a and supraorbital a.

Question 11

What artery does the long posterior ciliary a. anastomose with?

Answer 11

Anterior ciliary a. from the lacrimal a.

Question 12

Venous drainage from the eye

Answer 12

Can go down into infraorbital v. and into the facial v.

Can go posterior to pterygoid plexus.

Can go to superior and inferior ophthalmic vs. and then to the cavernous sinus.

Question 13

Which small veins drain the posterior eyeball? What is the next vein they drain into?

Answer 13

Vorticose veins –> superior/inferior ophthalmic vs.

Question 14

Central Retinal V. occlusion is caused by:

What can it lead to?

Answer 14

“ketchup”
Hardening of the CRA, HTN in the CRA can compress the CRV.

Can lead to hemorrhages and dilated veins.

Question 15

Central Retinal A. occlusion is caused by?

What can it lead to?

Answer 15

“pale and red spot”
Atherosclerosis, embolism.

White appearing retina, cherry red spot, attenuated vessels.

Question 16

Parts of the lacrimal apparatus (4)

Answer 16

Lacrimal gland
Lacrimal canaliculi
Lacrimal sac
Nasolacrimal duct

Question 17

Tear production (3)

Answer 17

1. Greater petrosal n. (CN VII) and deep petrosal n. meet at pterygoid canal.
2. PSNS fibers synapse in pterygopalatine ganglion.
3. Travel with V2, then with zygomatic branch, then to lacrimal n. of V1.

Question 18

Ciliary body

Answer 18

Ciliary body: circumferential tissue inside eye made of ciliary m. and ciliary processes.

Question 19

Ciliary processes function

Answer 19

Secrete aqueous humor which fills anterior and posterior chambers.

Question 20

Where is the anterior chamber?

Answer 20

Space between cornea and iris/pupil.

Question 21

Where is the posterior chamber?

Answer 21

Space between iris/pupil and lens and ciliary body.

Question 22

Flow of aqueous humor

Answer 22

Begins at ciliary process –> posterior chamber –> anterior chamber –> scleral venous sinus (Schemm’s canal)

Question 23

What causes glaucoma?

Answer 23

Blockage of scleral venous sinus (Schemm’s canal) causes increased pressure –> glaucoma.

Question 24

Microhyphema
Grade I
Grade II
Grade III 
Grade IV

Answer 24

Microhyphema - some circulating RBCs.
Grade I - < 1/3 anterior chamber vol.
Grade II - 1/3-1/2 anterior chamber vol.
Grade III - > 1/2 anterior chamber vol.
Grade IV - total anterior chamber vol.

Question 25

What happens when the ciliary ms. contract? (3)

Answer 25

Decreases size of ciliary body.
Reduces tension on suspensory L.
Lens becomes more rounded (for near vision).