3.2 Orbit

Question 1

What part of the orbit are generally the thinest and present significant clinical threat of becoming fractured or eroded in persistent infection?

Answer 1

medial wall & floor

Question 2

Fluid (tears) is drained from the medial corner of the eye through a small opening or … on the medial aspect of each eyelid.

Answer 2

punctum

Question 3

Fluid (tears) are drained from the puncture into the … that opens into the nasal cavity?

Answer 3

nasolacrimal duct

Question 4

The nasolacrimal duct opens into the nasal cavity under the … on the lateral wall.

Answer 4

inferior concha

Question 5

Each eyelid contains a semilunar plate of dense CT called a …

Answer 5

tarsal plate

Question 6

Embedded in each plate are a number of … that secrete a fatty substance keeping the lids from sticking together when closed.

Answer 6

tarsal glands

Question 7

The tarsal plates are anchored to the orbital margin by …

Answer 7

medial and lateral palpebral ligaments

Question 8

Voluntary (skeletal) muscle that raises the upper eyelid.

Answer 8

levator palpeerde superioris

Question 9

In it’s raised position, an involuntary SM is responsible for the “tone” of the eyelid. (eyelid should rest just above the iris of the eye)

Answer 9

superior tarsal muscle (Mueller’s)

Question 10

The superior tarsal muscle is innervated by … that travel with the frontal nerve

Answer 10

sympathetic fibers

Question 11

A lesion of the SNS - superior cervical ganglion (Horner’s syndrome) causes

Answer 11

partial ptosis (drooping of the eyelid)

Question 12

What are the eye abductor muscles?

Answer 12

Lateral rectus (obliques)

Question 13

What are the eye adductor muscles?

Answer 13

Medial rectus (Superior and Inferior recti)

Question 14

What are the eye elevator muscles?

Answer 14

Superior rectus, Inferior oblique

Question 15

What are the eye depressor muscles?

Answer 15

Inferior rectus, Superior oblique

Question 16

What are the eye intortion muscles?

Answer 16

Superior oblique (Superior rectus)

Question 17

What are the eye extortion muscles?

Answer 17

Inferior oblique (Inferior rectus)

Question 18

How should the pt look to test SR?

Answer 18

abduct and look up

Question 19

How should the pt look to test IR?

Answer 19

abduct and look down

Question 20

How should the pt look to test SO?

Answer 20

adduct and look down

Question 21

How should the pt look to test IO?

Answer 21

adduct and look up

Question 22

The external fibrous layer of the eye is composed of the posterior 5/6 which is … and the anterior 1/6 which is …

Answer 22

sclera (white of eye) and cornea

Question 23

A contractile diaphragm anterior ro the lens in the middle vascular layer of the eyeball.

Answer 23

iris

Question 24

What are the 2 muscles of the iris?

Answer 24

sphincter papillae and dilator pupillae

Question 25

What is the principle blood supply to the orbit?

Answer 25

ophthalmic artery

Question 26

The ophthalmic artery is a branch of the ...

Answer 26

internal carotid artery

Question 27

What is the relationship of the ophthalmic a. and the optic n. in the optic canal?

Answer 27

Ophthalmic artery travels superior to the optic nerve (army over navy)

Question 28

The ophthalmic a. passes anteriorly toward the ... wall of the orbit.

Answer 28

medial wall

Question 29

The sup. and inf. ophthalmic veins exit the orbit via the...

Answer 29

superior orbital fissure

Question 30

The sup. and inf. ophthalmic veins empty into the ...

Answer 30

cavernous sinus

Question 31

The sup and inf. ophthalmic veins originate in the anterior aspect of the orbit, as connecting veins from the ...

Answer 31

supraorbital and angular veins

Question 32

The frontal nerve is the largest of the V1 branches and lies on top of ...

Answer 32

levator palpeerde superioris .

Question 33

The frontal n. divides into 2 nerves, the lateral being ... and the medial is ...

Answer 33

supra-orbital n. and supratrochlear n.

Question 34

What is the the lateral branch of V1?

Answer 34

lacrimal n.

Question 35

What is the medial branch of V1?

Answer 35

nasociliary n.

Question 36

What are branches of the nasociliary n. that convey sinus pain?

Answer 36

ant. and post. ethmoidal nn.

Question 37

A branch of the nasociliary n. the long ciliary nn. has what function?

Answer 37

sensory innervation of the iris and cornea

Question 38

Sympathetics hitchhike on the long ciliary nn. to innervate the ...

Answer 38

dilator pupillae m.

Question 39

What branch of the nasociliary n. originates and passes through the ciliary ganglion without synapsing?

Answer 39

Short ciliary nn.

Question 40

The superior division of the Oculomotor n. (CN III), provides motor innervation for ...

Answer 40

levator palpeerde superioris, superior rectus

Question 41

The inferior division of the Oculomotor n. (CN III), provides motor innervation for ...

Answer 41

medial rectus, inferior rectus, and inferior oblique

Question 42

The preganlionic parasympathetic fibers travel via ... of CN III, and synapse in ...

Answer 42

inferior division, ciliary ganglion

Question 43

Postsynaptic parasympathetic fibers travel via ...

Answer 43

short ciliary nn.

Question 44

Parasympathetics of the short ciliary nn. supply the ... that regulates tension on lens for focusing.

Answer 44

sphincter papillae and ciliaris m.

Question 45

What are the symptoms of Oculomotor (CN III) Palsy?

Answer 45

Down and outward glaze (SO and LR only not effected), dilated (no sphincter papillae), and Ptosis (no LPS)

Question 46

Postganglionic sympathetic fibers travel from ... to the orbit, via 2 pathways, short and long ciliary nn.

Answer 46

internal carotid plexus

Question 47

The lacrimal gland is innervated by what cranial nerve?

Answer 47

Facial (CN VII)

Question 48

What gives motor innervation to Superior Oblique muscle?

Answer 48

Trochlear (CN IV)

Question 49

What are the symptoms of Trochlear (CN IV) Palsy?

Answer 49

Extortion (outward rotation) of the affected eye due to unopposed IO, which causes diplopia, the pt may tilt head to manually introit the eye

Question 50

What are the symptoms of Abducens (CN VI) Palsy?

Answer 50

at rest the eye is adducted (since LR can't abduct); when asked to gaze to one side the affected eye can't abduct