Orbit Contents (M1)

Question 1

how many coats (tunics) does the globe (eyeball/eye) have and what are the 3 chambers

Answer 1

3 coats (tunics):
- outer fibrous later (cornea and sclera)
- middle vascular layer or uvea (iris, ciliary body, choroid)
- inner neural layer (retina)
3 chambers filled with fluid:
- anterior chamber
- posterior chamber
- vitreous chamber

Question 2

location of tenon’s capsule (bulbar fascia)

Answer 2

anteriorly: merges with sclera/conjunctiva at limbus
posteriorly: continuous with dural sheath of ON

Question 3

composition of tenon’s capsule

Answer 3

sheet of dense connective tissue that covers sclera and tendons of EOMS as they insert into sclera

Question 4

function of tenon’s capsule

Answer 4

alarm system.
provides a strong barrier - separates globe from contents of orbit and prevents orbital infections from entering globe

Question 5

composition of orbital septum (palpebral fascia)

Answer 5

sheet of dense connective tissue that extends the entire rim of the orbit to the tarsal plate; continuous with periosteum at superior and inferior orbital rim

Question 6

function of orbital septum

Answer 6

anterior barrier of orbit: separates eyelids and lacrimal sac from orbit
- prevents facial/eyelid/nasolacrimal system infections from entering orbit
keeps orbital fat in place

Question 7

composition of periorbita (orbital fascia, periosteum)

Answer 7

sheet of dense connective tissue that covers bones of orbit

Question 8

location of periorbita

Answer 8

anteriorly: continuous with periosteum of facial bones and orbital septum
posteriorly: continuous with dural sheath of ON and forms common tendinous ring

Question 9

function of periorbita

Answer 9

attachment sit for muscles, tendons, and ligaments.
support structure for vascular supply to the orbital bones

Question 10

composition of Whitnall’s Ligament (superior transverse ligament)

Answer 10

transverse dense connective tissue located in superior orbit - courses from lateral orbital wall to medial orbital wall

Question 11

function of Whitnall’s Ligament

Answer 11

provides support and maintains spatial relationships between anatomic structures in the superior orbit

Question 12

where is Whitnall’s Ligament formed?

Answer 12

formed by condensation of levator muscle - point where levator muscle fibers end and levator aponeurosis begins

Question 13

composition of Lockwood’s Ligament (Suspensory ligament)

Answer 13

transverse dense connective tissue located in inferior orbit - courses from lateral orbital wall to medial orbital wall

Question 14

function of Lockwood’s Ligament

Answer 14

provides support and maintains spatial relationships between anatomic structures in the inferior orbit.
contributes to the formation of capsulopalpebral fascia

Question 15

composition of medial check ligament

Answer 15

transverse dense connective tissue that is an expansion of the sheath of the medial rectus

Question 16

attachment of medial check ligament

Answer 16

lacrimal bone

Question 17

function of medial check ligament

Answer 17

prevents overaction of the medial rectus

Question 18

composition of lateral check ligament

Answer 18

transverse dense connective tissue that is an expansion of the sheath of the lateral rectus

Question 19

attachment of lateral check ligament

Answer 19

attaches to zygomatic bone

Question 20

function of lateral check ligament

Answer 20

prevents overaction of lateral rectus

Question 21

what ligaments form a supporting hammock-like formation for the globe

Answer 21

Whitnall’s ligament
Lockwood’s ligament
check ligaments

Question 22

function of orbital septum system

Answer 22

web of interconnecting connective tissue septa.
organizes the orbital space surrounding globe - anchors and supports EOMs, nerves, and blood vessels

Question 23

orbital nerves

Answer 23

II optice nerve
III oculomotor
IV trochlear
V1 ophthalmic
V2 maxillary
VI abducens

Question 24

orbit blood vessels

Answer 24

ophthalmic artery and branches
superior and inferior ophthalmic vein and branches

Question 25

orbit muscles

Answer 25

extraocular muscles and eyelid refractors

Question 26

name the extraocular muscles

Answer 26

recti muscles:
- medial rectus (MR)
- lateral rectus (LR)
- superior rectus (SR)
- inferior rectus (IR)
oblique muscles:
- superior oblique (SO)
- inferior oblique (IO)

Question 27

function of extraocular muscles

Answer 27

control movement of globe

Question 28

name the eyelid retractors

Answer 28

levator palpebrae
superior and inferior tarsal muscles
capsulopalpebral fascia (not actually a muscle)

Question 29

function of eyelid retractors

Answer 29

control movement of eyelids