Lab 21 Orbit

Question 1

Which side of the eyeball is the optic nerve found on?

Answer 1

Lateral side

Question 2

What is a sheet of CT between the tarsal plate and the bony orbital margin?

Answer 2

The orbital septum

Question 3

Prior to and at the optic nerve, the nasociliary nerve gives off what?

Answer 3

Long ciliary nerves

Question 4

What nerve passes directly anterior toward the superior orbital margin and bifurcates at its midpoint?

A. Lacrimal
B. Frontal
C. Trochlear

Answer 4

B. Frontal

Bifurcates into the supratrochlear nerve (more medial) and the supraorbital nerve (more lateral)

Question 5

What connects the ganglion to the posterior surface of the eyeball?

Answer 5

Short ciliary nerves

Question 6

The tarsal plates are found deep to what?

Answer 6

The palpebral portion of the orbicularis oculi muscle

Question 7

What 3 superficial nerves pass from near the apex of the orbit superior to the extraocular muscles?

Answer 7

Frontal nerve
Lacrimal nerve
Trochlear nerve

Question 8

Radial muscle fibers that work slowly to open the pupil

Answer 8

Dilator papillae

Question 9

What do all the rectus muscles have in COMMON?

Answer 9

Common attachment to the common tendinous ring

Question 10

Part of the vascular middle layer (color of eye)

Answer 10

iris

Question 11

Clear, fibrous outer layer (anterior 1/6 of ball, 20%)

Answer 11

Cornea

Question 12

White, fibrous outer layer (posterior 5/6 of ball, 80%)

Answer 12

Sclera

Question 13

Space between the iris and anterolateral part of lens

Answer 13

Posterior chamber

Question 14

What passes through the common tendinous ring? (There are 6 things)

Answer 14

Optic nerve (II)
Abducens nerve (VI) 
Nasociliary nerve
Superior and inferior divisions of the oculomotor nerve 
Central artery of the retina

Question 15

What is a connective tissue sheath that will block the view/access to all contends of the orbit? What can be seen through this?

Answer 15

Periorbita

The frontal nerve can be seen through it

Question 16

Circular muscles of iris that work to quickly close the pupil

Answer 16

Sphincter papillae

Question 17

Where the optic nerve and retinal vessels enter/leave

Answer 17

Optic disc

Question 18

Opening in the middle of the iris

Answer 18

Pupil

Question 19

What nerve is medial to frontal nerve and follows the superior surface of the superior oblique? What does it innervate? ;)

Answer 19

Trochlear nerve, innervates the superior oblique

Question 20

What is the bulbar conjunctiva attached to?

Answer 20

The sclera

Question 21

What nerve crosses at an angle from posterolateral to anteromedial and is superficial to the optic nerve?

What is it a branch of?

Answer 21

Nasociliary nerve is a branch of V1

Question 22

Space between the cornea and the iris/pupil

Answer 22

Anterior chamber

Question 23

Following the inferior oblique muscle posteriorly will lead to the _____ division of the _______ nerve.

A. Inferior, oculomotor
B. Superior, oculomotor
C. Inferior, optic
D. Superior, optic

Answer 23

A. Inferior division of the oculomotor nerve

Question 24

Which muscle bends at an acute angle to attach to the posterolateral portion of the eyeball?

Action(s) in neutral gaze?

Action(s) when abducted?

Action(s) when adducted?

Answer 24

Superior oblique, goes through the trochlea

Neutral gaze- intortion, abduction, depression

Abducted- intort

Adducted- depression

Question 25

What is located superolaterally? A. Trochlea B. Inferior oblique muscle C. Lacrimal gland

Answer 25

C. Lacrimal gland The trochlea is superomedially The inferior oblique muscle is attached inferomedially found more anterior at its origin but pass more posterior to its insertion on the eyeball

Question 26

What is found deep to the lacrimal nerve? Hint: it has 2 heads What passes through the 2 heads? Medial or lateral surface?

Answer 26

The lateral rectus The abducens passes through the 2 heads on the medial surface near the apex of the orbit

Question 27

Put these in order of superficial to deep: Superior rectus Frontal nerve Levator palpebrae superioris CN III

Answer 27

Superficial- frontal nerve, levator palpebrae superioris, superior rectus, CN III- deep

Question 28

What is the ophthalmic artery a branch of? It crosses _______ to the optic nerve from a ______ position. A. Inferior, medial B. Superior, medial C. Superior, lateral D. Inferior, lateral

Answer 28

The internal carotid artery C

Question 29

``` What is a slit like opening between the eyelids? A. Palpebral fissure B. Lacrimal caruncle C. Lacrimal papilla D. Lacrimal puncta ```

Answer 29

A. Palpebral fissure The lacrimal caruncle is a fleshy bump in the medial angle The lacrimal papilla is a small bump on the medial end of the eyelid The lacrimal punta is a small opening at the apex of the papilla (used for dilation)

Question 30

What nerve follows the lateral wall of the orbit to the lacrimal gland?

Answer 30

Lacrimal nerve :)

Question 31

Inner layer, likely detached in cadaver eye

Answer 31

Retina

Question 32

Where the vitreous body once was

Answer 32

Virtuous chamber

Question 33

What is found between the optic nerve and the lateral rectus muscle? Where is this usually found?

Answer 33

The ciliary ganglion Closer to the apex than to the eyeball

Question 34

What is a membrane that lines the surface of the eyeball (sclera)? A. Conjunctival sac B. Palpebral conjunctiva C. Bulbar conjunctiva

Answer 34

C. Bulbar conjunctiva The palpebral conjunctiva is the membrane that lines the inner surface of the eyelid The conjunctival sac is a potential space between bulbar and palpebral conjunctivae