L4 The Orbit & Eye

Question 1

Eyelid

Answer 1

Question 2

Tarsal plates
P608

Answer 2

Question 3

Ligaments

Answer 3

check left and right before crossing the street

Question 4

Bones

Answer 4

Question 5

Bones around the eye

Answer 5

Question 6

What are in these orbital foramina?

Answer 6

Question 7

The orbit

Lateral walls are … degrees to each other
Optical axes are … degrees in relation to each other

Answer 7

Lateral walls are 90 degrees to each other
Optical axes are 45 degrees in relation to each other

Question 8

Eyeball

Answer 8

Question 9

Retina
Macula only has?
Blind spot is where? Doesn’t have?

Answer 9

Question 10

Aqueous humor
— Produced by?
— Drains into?

Answer 10

Question 11

Vitreous humor — what does it do?

Answer 11

Supports the retina

Question 12

Intrinsic muscles
Innervation is in orange
Which muscle dilates the pupil?
By which innervation?
Which muscle constricts the pupil?
By which innvervation?
Which muscle changes the shape of the lens?
By which innvervation?

Answer 12

Which muscle dilates the pupil? dilator pupilae
By which innervation? sympathetic

Which muscle constricts the pupil? sphincter pupilae
By which innvervation? PNS via CN III

Which muscle changes the shape of the lens? intrinsic eye muscle
By which innvervation? CN III

Question 13

Extraocular muscles
— What are the 7 muscles?
— Which two are posterior to the equator?

Answer 13

Question 14

Eye muscle action and innvervation — look at muscle table

Answer 14

Note that they are all Oculomotor CN III
Except:
Lateral rectus: LA6 (for CN IV Abducens)
Superior oblique: SO4 (CN IV Trochlear)

Question 15

Clinical testing for extraocular muscles

Answer 15

Question 16

Pathway

Answer 16

Question 17

Related nerves

Answer 17

Opthalmic branch of the
Remember LR6 and SO4 — see the nerves innvervating the respective muscles
Ciliary ganglion is where SNS and PNS synapse

Question 18

Superior orbital fissure
Note what is inside and outside the ring

Answer 18

Opthalmic artery is a branch of the ICA
Which gives off: supraorbital and supratrochlear

Outside
— Lacrimal
— Frontal
— Trochlear
nobody can see me crying OUT front

Question 19

Related nerves — know this for practical
P609
The frontal nerve is a continuation of which nerve?
What does the frontal nerve continue as towards the eyeball?
Which branch comes off medially
Which branch comes off laterally?

Answer 19

The frontal nerve is a continuation of which nerve? Trigeminal CN V, V1 Opthalmic nerve
What does the frontal nerve continue as towards the eyeball? supraorbital
Which branch comes off medially? supratrochlear
Which branch comes off laterally? lacrimal

Question 20

What nerve is this?

Answer 20

Question 21

Short and long ciliary nerves

Answer 21

Question 22

Nasociliary nerve

Answer 22

Question 23

Identify the nerves

Answer 23

Question 24

Arterial blood supply
Branches of which artery supply the eyeball?
Which comes off which main artery?

Answer 24

Branches of the opthalmic artery supply the eyeball
The Ophthalmic artery is a branch of the ICA

Question 25

Venous blood supply
All the venous branches around the eyeball drain into which vein?

Answer 25

Ophthalmic vein

Question 26

Lacriminal apparatus
Nerve, artery, vein? Super simple…
The nerve is a branch of?

Answer 26

Lacrimal nerve, artery and vein!
lacrimal nerve is a branch of the ophthalmic nerve

Question 27

Autonomic innervation
Innvervation of the lacrimal gland

Answer 27

Facial nerve is coming from the Pons
Greater petrosal — pre-ganglion PNS