Orbit

Question 1

Parasagittal plane

Answer 1

Parallel to the Sagittarius suture of the skull

Question 2

7 bones that make up the orbit

Answer 2

palatine 
lacrimal 
zygomatic 
maxillary 
ethmoid 
sphenoid 
frontal

Question 3

unpaired/ single bones that make up the orbit

Answer 3

sphenoid
ethmoid
frontal

Question 4

depth from the back of the eye to the optic foramen

Answer 4

18mm

Question 5

Inferiors orbital fissure separates

Answer 5

floor of the orbit and the lateral wall

Question 6

What makes up the roof of the orbit

Answer 6

lesser wing of sphenoid and frontal bones

Question 7

the lesser wing of sphenoid contains

Answer 7

forms the apex of the orbit
contains the optic canal
contains communication with middle cranial fossa

Question 8

orbital plate of the frontal bone contains

Answer 8

lacrimal fossa , supraorbital notch , fovea for trochlea of superior oblique

Question 9

superior orbital fissure is located____

and separates ___

Answer 9

b/w lesser and greater wing of sphenoid

separates roof and lateral wall of orbit

Question 10

floor of the orbit is made up of

Answer 10

maxilla, zygomatic and palatine bones

Question 11

infraorbital grove is located ____ communicates with _____ and transmits

Answer 11

• floor of orbit/ maxillary bone
• pterygopalatine fossa
• infraorbital nerve CNV2 and vessels

Question 12

what enters the orbit from the pterygopalatine fossa

Answer 12

infraorbital and zygomatic nerves of the cranial fossa

Question 13

blow out fracture usually involves the

Answer 13

orbital floor

infraorbital groove

Question 14

bones that make up the medial wall of the orbit

Answer 14

sphenoid, ethmoid, lacrimal , maxillary

Question 15

thinnest wall of the orbit?

Answer 15

medial wall

Question 16

where is the lacrimal sac located

Answer 16

in the medial wall of the orbit

Question 17

where are the anterior and posterior crests of the lacrimal sac located ?

Answer 17

anterior: maxillary bone

posterior : lacrimal bone

Question 18

the lacrimal sac fossa continues inferiorly within the maxillary bone as the

Answer 18

nasolacrimal canal then the nasal cavity

Question 19

where are the anterior and posterior ethmoidal foramina located? what do they transmit?

Answer 19

located between ethmoid and frontal bones

transmit: ethmoidal artery, vein and nerve ( branch of nasociliary: CNV 1 ) and lymphatics

Question 20

bones that make up the lateral wall of the orbit?

Answer 20

zygomatic and greater wing of sphenoid

Question 21

where is the meningo orbital foramen located

Answer 21

sphenoid bone, lateral wall

Question 22

Whitnall’s turbercle

Answer 22

1. check ligament of lateral rectus muscle
2. suspensory ligament (lockwood)
3. lateral horn of levator aponeurosis
4. lateral palpebral ligament

Question 23

where is the lateral orbital tubercle?

Answer 23

zygomatic bone, 4-5mm internal to the lateral orbital rim

Question 24

bones that make up the orbital margin

Answer 24

zygomatic, frontal, maxillla

Question 25

what margin is discontinuous and why?

Answer 25

medial margin dude to lacrimal sac fossa

Question 26

major orbital openings include?

Answer 26

1. optic foramen and canal 2. SOF 3. IOF 4. infraorbital groove, canal, and foramen 5. ethmoidal foramina 6. supraorbital notch/ foramen

Question 27

optic foramen/ canal is located in? and transmits? and opens to which fossa?

Answer 27

lesser wing of sphenoid transmits: optic nerve ophthalmic artery and sympathetic nerves opens to middle cranial fossa

Question 28

SOF is divided into superior and inferior portions by

Answer 28

the common tendinous ring (annulis of zinn)

Question 29

SOF transmits (5)

Answer 29

CN III, IV, VI and ophthalmic nerve CNV1 ( branches: lacrimal, frontal, and nasociliary) and ophthalmic vein

Question 30

what's located outside of the annulus of zinn

Answer 30

branch of the lacrimal artery (CNV1 branches) :lacrimal nerve and frontal nerve CNIV : trochlear superior ophthalmic vein

Question 31

whats located inside the annulus of zinn

Answer 31

CNIII (inferior and superior) Nasociliary nerve (CNV1 branch) CNVI abducens

Question 32

structures traveling inside the optic foramen go through the common tendinous ring but not the SOF

Answer 32

true

Question 33

where is the IOF located

Answer 33

between maxilla and greater wing of sphenoid

Question 34

how does the IOF communicate with the orbit

Answer 34

it opens into pterygopalentine and infratemporal fossae

Question 35

what does the IOF transmit

Answer 35

- inferior ophthalmic vein - infraorbital nerve (terminal branch of CNV2) - infraorbital artery and vein - zygomatic nerve of CNV2 - autonomic fibers from pterygopalatine - emissary veins

Question 36

infraorbital foramen transmits

Answer 36

- infraorbital artery (maxillary artery branch) - nerve (terminal branch of CNV2 maxillary nerve) - vein

Question 37

infraorbital nerve course

Answer 37

foramen rotundum to pterygopalatine fossa, IOF to orbit, infraorbital canal to infraorbital foramen

Question 38

supraorbital noth/foramen transmits

Answer 38

supraorbital nerve (terminal branch of frontal nerve) artery (ophthalmic artery branch) and vein

Question 39

orbit innervation

Answer 39

CNV1 branches: nasociliary and its branches AE, PE, IT, frontal with branches SO and ST and lacrimal and CNV2 branches: infraorbital , zygomaticofacial, and zygomaticotemporal

Question 40

where are paranasal sinuses located

Answer 40

within frontal, sphenoid, ethmoid, and maxillary bones | surround the orbit

Question 41

what divides sinuses from the orbit

Answer 41

lamina papyrecea

Question 42

orbital cellulitis can be secondary from

Answer 42

sinusitis mainly ethmoidal

Question 43

periorbita /orbital periosteum is continuous with

Answer 43

dura mater

Question 44

dense connective tissue that lines the bones in the orbit is called? innervated by? derived from?

Answer 44

periorbita CNV periosteal dura matter

Question 45

optic nerve is surrounded by

Answer 45

3 meningeal layers

Question 46

continumm of periorbital into eyelid

Answer 46

orbital septum

Question 47

orbital septum functions

Answer 47

1. barrier to prevent spread of infections from the eyelid into the orbit 2. isolates lacrimal sac 3. maintains orbital fat in place

Question 48

what's the difference b/w preseptal and orbital cellulitis

Answer 48

orbital cellulitis is more serious preseptal: inflammation anterior to the orbital septum orbital: inflammation posterior to orbital septum

Question 49

dermatochalasis

Answer 49

weakening of the orbital septum which causes orbital fat to protrude forward can decrease palpebral fissure eyelid bags

Question 50

tenons capsule

Answer 50

aka bulbar fascia | encloses the eye sclera from the limbus to the optic nerve

Question 51

anteriorly located between the conjunctiva and the sclera and site for injection of anesthesia during eye surgery

Answer 51

tenons capsule

Question 52

where is the suspensory ligament aka Lockwood located

Answer 52

between inferior rectus and inferior oblique muscles

Question 53

where does the suspensory ligament insert

Answer 53

whitnalls tubercle

Question 54

orbital septal system is CT located between

Answer 54

periorbita and the bulbar fascia (tenons capsule

Question 55

intraconal fat is located? | how woulda intraconal mass be shown on the patient ?

Answer 55

inside the CT that connects the 4 rectus EOMS (intermuscular fascia) -eye pushed forward

Question 56

extraconal fat is located | how would a extraconal mass be shown?

Answer 56

b/w the rectus EOMS and the periorbita (outside the intermuscular fascia) eye pushed in and angle

Question 57

exophthalmos is? | most common cause?

Answer 57

proptosis of protrusion of the eyeball - palpebral fissure is larger than 15mm - thyroid eye disease/ grave's disease