CT of the Orbit

Question 1

True or false: Tenon’s capsule is outer to the conjunctiva.

Answer 1

False; it is inner to the conjunctive. It is also outer to the episclera.

Question 2

To what bones does the suspensory ligament attach?

Answer 2

To the lacrimal bone and the zygomatic bone.

Question 3

What is exophthalmos?

Answer 3

A condition in which a space-occupying structure causes protrusion (proptosis) of the globe.

Question 4

What is the difference between extrafusal and intrafusal fibers?

Answer 4

Extrafusal fibers are contractile; intrafusal fibers are not.

Question 5

What is the difference between the global layer and the orbital layer of EOM organization?

Answer 5

Global lays adjacent to the globe, extends the full length of the muscle, and causes movement of the globe.Orbital layer lays adjacent to the bone, ends before the muscle tendon, and works to position CT muscle pulleys that influence muscle rotation.

Question 6

Name the connective tissue that covers the orbital bones.

Answer 6

Periorbita, or orbital periosteum, or orbital fascia.

Question 7

What is the function of the periorbita?

Answer 7

Carry blood and nerve supply to bones.Attachment for muscles, tendons, and ligaments.

Question 8

What is the function of the orbital septum?

Answer 8

Prevent infections of face from entering orbit.

Question 9

What is the orbital septum’s relationship with the check ligaments?

Answer 9

Anterior to both the medial and lateral check ligaments.

Question 10

What is the orbital septum’s relationship with the palpebral ligaments?

Answer 10

Anterior to the lateral palpebral ligament BUT posterior to the medial palpebral ligament.

Question 11

What is the orbital septum’s relationship to the lacrimal sac?

Answer 11

Posterior to the lacrimal sac, which is on the medial side.

Question 12

What is the orbital septum’s relationship to Horner’s muscle?

Answer 12

Posterior to Horner’s muscle, which is on the medial side.

Question 13

What is the name of the hammock-like sheet of dense connective tissue that supports the globe inferiorly?

Answer 13

Suspensory ligament (of Lockwood)

Question 14

What is another name for Tenon’s capsule?

Answer 14

bulbar fascia

Question 15

Where is the bulbar fascia located?

Answer 15

Surrounding the globe, outer to the episclera, inner to the conjunctiva (Tenon’s capsule is another name for bulbar fascia)

Question 16

What is the purpose of Tenon’s capsule?

Answer 16

Protects globe from orbital infection.Attachment for EOM.