Orbit And Eye

Front 1

What is tear production controlled by?

Back 1

Tear production controlled by parasympathetic innervation from facial nerve (VII)

Also sympathetics

Front 2

What do tears contain?

Back 2

Tears contain lysozyme and IgA

Tear film continuous

Front 3

What is the path of tear drainage?

Back 3

Tears drain into lacrimal puncta and via caniliculi into lacrimal sac that empties via nasolacrimal duct into inferior nasal meatus

Front 4

What is the superior wall of orbit?

Back 4

0rbital portion of frontal bone

Front 5

What is the Medial wall of orbit?

Back 5

mostly ethmoid bone

Medial walls are parallel, one to another

Front 6

What is the inferior wall of the orbit?

Back 6

mainly maxillary bone with contributions from zygomatic and palatine bones

Front 7

What is the lateral wall of the orbit?

Back 7

frontal portion of zygomatic bone and greater wing of the sphenoid bone

Front 8

What is the apex of the orbit?

Back 8

At the optic canal in the lesser wing of the sphenoid.

Front 9

Orbital axes diverge?

Back 9

At 45 degrees

Front 10

What are the contents of the orbit?

Back 10

Periorbita - Periosteum
Orbital fat
Nerves and vessels
Levator palpebrae superioris muscle and fascial sheath
Extraocular muscles with fascial sheaths
Eye (bulbus oculi)
Lacrimal apparatus

Front 11

Why does the orbital have fat in it?

Back 11

- Padding
- Allows eye movements

Front 12

What is the major blood supply to orbit?

Back 12

Opthalmic artery

1st branch of internal carotid

Front 13

What is the smallest branches of the opthalmic artery?

Back 13

One of smallest branches is the central artery of the retina.

Enters optic nerve to get to retina.

Front 14

Occlusion of the central artery of the retina causes what?

Back 14

blindness in that eye

Front 15

What blood supply penetrates the sclera to supply choroid and outer retina (pigment: rods and cones)?

Back 15

Posterior ciliary arteries

Front 16

What are the two blood supplies to the eyeball?

Back 16

Central artery of the retina, posterior ciliary arteries

Front 17

What are the four muscles that arise from the tendinous ring?

Back 17

Lateral rectus - abduction
Inferior rectus – downward gaze
Medial rectus - aduction
Superior rectus – upward gaze

Front 18

What are eyelids covered internally by?

Back 18

By palpebral conjunctivum

Palpebral conjunctivum is continuous with the bulbar conjunctivum

Front 19

What forms the skeleton of the eyelids?

Back 19

Tarsal plates - (dense fibroelastic tissue)

Front 20

What forms the muscular portion of the eyelids?

Back 20

Orbicularis oculi forms the muscular portion of the lids

Innervation is via the facial nerve (CN VII)

Front 21

What muscle is responsible for the blink reflex?

Back 21

Orbicularis oculi

Front 22

What two glands lubricate the edges of the eyelids?

Back 22

Tarsal glands
Meibomian, glands

Front 23

What muscle elevates the upper eyelid?

Back 23

Levator palpebrae superioris muscle elevates upper lid

Innervated by the oculomotor nerve (III)

Front 24

What does the Muller's muscle do?

Back 24

Smooth muscle that keeps the eyelid from drooping.

Innervated by postganglionic sympathetics from the superior cervical ganglion

Front 25

What occurs if the nerve or Muller's musce is damaged/paralyzed?

Back 25

Paralysis causes ptosis or drooping of the upper lid

Part of Horner’s Syndrome

Front 26

What is the anastamosis around the orbit?

Back 26

Opthalmic --> angular --> infraorbital (branch of maxillary artery off of ext carotid)

Front 27

What is special about the veins around the orbit?

Back 27

They have no valves. They all drain posteriorly into the cavernous sinus, so infection can spread this way.

Front 28

What is the venous drainage around the orbit?

Back 28

Facial vein --> angular vein
Infraorbital vein --> Inferior opthalmic
Supra orbital + nasofrontal--> superior opthalmic

Vorticose veins (from eye)

All into pertygoid venous plexus or to cavernous sinus

Front 29

What is outside the tendinous ring of the orbit?

Back 29

Frontal nerve
Lacrimal nerve
Trochlear nerve
Superior opthalmic vein
Levator palpebrae superioris
Superior oblique
Inferior opthalmic vein
Inferior oblique

Front 30

What is inside the tendinous ring of the orbit?

Back 30

Oculomotor nerve = superior and inferior divisions
Nasociliary nerve
Abducent nerve
Opthalmic artery
Optic nerve

Front 31

Where does the inferior oblique originate?

Back 31

On the maxillary bone

Front 32

What are the nerves that enter the orbit?

Back 32

Frontal nerve
Medial/lateral branch of supraorbital nerve
Supratrochlear
Nasociliary
Lacrimal nerve to gland
Abducent
Trochlear nerve

Front 33

What is the parasympathetic innervation to the eye?

Back 33

Short ciliary nerves off of the ciliary ganglion.

Front 34

What is the name of the tendon that holds the superior oblique muscle in place?

Back 34

Trochlea

Front 35

What is the action of superior oblique?

Back 35

Intorsion of eye (towards nose)

Makes eye look down

Front 36

What is the action of inferior oblique?

Back 36

Extorsion of eye (away from nose)

Makes eye look up

Front 37

How do you test superior rectus?

Back 37

Turn eye laterally to line up with axis. (23 degrees)

Look up.

Front 38

How do you test inferior rectus?

Back 38

Turn eye laterally to line up with axis. (23 degrees)

Look down.

Front 39

How do you test superior oblique?

Back 39

Line eye up with pull of tendon. (51 degrees)

Look medial and down

Front 40

How do you test inferior oblique?

Back 40

Line eye up with pull of tendon. (51 degrees)

Look medial and up

Front 41

What pattern do you use to test the eye?

Back 41

H pattern

Front 42

When one eye abducts, the other eye should?

Back 42

ADDuct

Front 43

How do you test lateral rectus?

Back 43

Look directly lateral

Front 44

How do you test medial rectus?

Back 44

Look directly medial