Orbital Contents

Question 1

What six general things does the bony orbit contain?

Answer 1

The globe, CT, EOMs, nerves, vessels, and fat

Question 2

What is the globe?

Answer 2

The eyeball, consisting of 3 tunics and 3 chambers

Question 3

What are the three tunics of the globe?

Answer 3

Outer fibrous, middle vascular, inner neural

Question 4

What are the three chambers within the globe?

Answer 4

Anterior, posterior, and vitreous

Question 5

What is tenon’s capsule?

Answer 5

Aka bulbar fascia, CT covering sclera and EOM tendon insertions, barrier b/w globe and contents of orbit, prevents orbital infections from entering globe

Question 6

What is tenon’s capsule continuous with?

Answer 6

Sclera/conj at the limbus and dural sheath of optic nerve

Question 7

What are the four layers of sclera?

Answer 7

Sclera, episclera, tenon’s capsule, conjunctiva (all continuous with cornea at limbus)

Question 8

What is the orbital septum?

Answer 8

Aka palpebral fascia, dense CT extends the entire rim of the orbit to the tarsal plate, separates the eyelids and lacrimal sac from orbit and keeps orbital fat in place

Question 9

What connective tissue prevents facial/eyelid/nasolacrimal system infections from entering the orbit?

Answer 9

Orbital septum

Question 10

What is the orbital septum continuous with?

Answer 10

Periosteum at superior and inferior orbital rim

Question 11

What CT is the anterior barrier of the orbit?

Answer 11

Orbital septum

Question 12

What CT prevents orbital infections from entering the globe?

Answer 12

Tenons capsule

Question 13

What is the periorbita?

Answer 13

Aka orbital fascia or periosteum, dense CT covering the bones or the orbit

Question 14

What is the periorbita continuous with?

Answer 14

Periosteum of facial bones and orbital septum anteriorly, dural sheath of optic nerve and forms common tendinous ring posteriorly

Question 15

What is whinall’s ligament?

Answer 15

Transverse(horizontal) dense CT in superior orbit, provides support and maintains spatial relationships b/w structures in superior orbit

Question 16

What forms whitnall’s ligament?

Answer 16

Condensation of levator muscle, where muscle fibers end and levator aponeurosis begins (tendon)

Question 17

What is Lockwood’s ligament?

Answer 17

Transverse dense CT in inferior orbit, support, maintains spatial relationships b/w an anatomical structures in inferior orbit

Question 18

What does lockwood’s contribute to?

Answer 18

Capsulopalpebral fascia (dense CT that moves lower lid)

Question 19

What is the medial check ligament?

Answer 19

Transverse dense CT that is an expansion of the sheath of the medial reclusive and attached to the lacrimal bone

Question 20

What is the purpose of the medial check ligament?

Answer 20

Prevent over action of the medial rectus

Question 21

What is the purpose of the lateral check ligament?

Answer 21

Prevent over action of the lateral rectus

Question 22

What is the lateral check ligament?

Answer 22

Transverse dense CT that is an expansion of the sheath of the lateral rectus, attaches to the zygomatic bone

Question 23

What is the orbital septal system?

Answer 23

Web of interconnecting CT septa, organizes the orbital space surrounding the globe, anchors and supports EOMs, nerves, and vessels

Question 24

Which nerves pass through the orbit?

Answer 24

II, III, IV, V1, V2, VI

Question 25

Which vessels pass through the orbit?

Answer 25

Ophthalmic artery + branches, superior and inferior ophthalmic vein + branches

Question 26

What are the EOMs?

Answer 26

Medial, lateral, superior and inferior Recti muscles and superior and inferior obliques

Question 27

What are the eyelid retractors?

Answer 27

Levator palpebrae, muller’s muscle, capsulopalpebral fascia

Question 28

What is orbital fat?

Answer 28

Adipose tissue filling space not occupied by orbital structures, predominant tissue in the orbital apex

Question 29

What is the role of orbital fat in the orbital apex?

Answer 29

Surrounds the optic nerve, separating it from the EOMs, separates the muscles in the orbit from the orbital walls

Question 30

What is the role of orbital fat in the anterosuperior orbit?

Answer 30

2 fat pads are anterior to the levator aponeruosis (preaponeurotic fat pads) founde nasal and central, held in place by orbital septum

Question 31

What is the role of orbital fat anteriorly and inferiorly?

Answer 31

3 fat pads are posterior to the orbital septum and anterior to the capsulopalpebral fascia, located nasal, central, and temporal, held in place by the orbital septum