Anatomy Mt. 1 Eyeball Stuff

Front 1

What does the petrous portion of the temporal bone hold?

Back 1

Middle and inner ear.

Front 2

Explain how a CN6 Palsy with papilledema can occur?

Back 2

CN 6 runs over the ridge of the petrous portion and is more susceptible to increased ICP.

Front 3

What are the signs and symptoms of CN6 Palsy?

Back 3

Horizontal diplopia and papilledema.

Front 4

The optic foramen/optic canal/optic nerve runs through this bone?

Back 4

Lesser wing of sphenoid

Front 5

What passes through the Foramen Rotundum?

Back 5

Maxillary (V2 of CN5)

Front 6

What passes through the Foramen Ovale?

Back 6

Mandibular (V3 of CN5)

Front 7

What passes through the foramen spinosum?

Back 7

Middle meningeal artery.

Front 8

What passes through the Superior Orbital Fissure?

Back 8

CN3, 4 and 6. V1 of CN5 (ophthalmic)

Front 9

What can happen with the ethmoid air cells?

Back 9

Infection in sinus can get through here to eye.

Front 10

What nerve can get affected in a blow out fracture?

Back 10

Infraorbital nerve in cheek.

Front 11

What is the thinnest bone in the medial wall of the orbit?

Back 11

Ethmoid bone (lamina papyracea)

Front 12

What is the horizontal dimension of the orbital margin?

Back 12

4cm

Front 13

What is the vertical dimension for the orbital margin?

Back 13

3.5cm

Front 14

How deep is the orbital margin?

Back 14

4.5cm

Front 15

What goes through the optic canal AND A.O.Z.

Back 15

Optic nerve and ophthalmic nerve

Front 16

What goes through the superior orbital fissure ABOVE the AOZ

Back 16

Lacrimal, frontal and trochlear nerves.

Superior ophthalmic vein.

Front 17

What goes through the superior orbital fissure AND AOZ

Back 17

CN3, nasocicilary (V1) and CN6 (abducens)

Front 18

What goes through inferior orbital fissure BELOW AOZ

Back 18

infraorbital nerve (V2), infraorbital artery and inferior ophthalmic vein.

Front 19

What is the function of sinuses?

Back 19

Lighten the skull and add resonance to the voice.

Front 20

What are the signs of orbital cellulitis?

Back 20

Double vision, infects EOMS, proptosis.

Looks like swollen red eyelid.

Infection gets in orbit, has easy access to brain.

Front 21

What is the periorbita?

Back 21

Outermost tissue that covers bones. Thickens to form AOZ. Carries blood supply to bones.

Front 22

What is the orbital septum continuous with?

Back 22

Rim of orbit and goes to tarsal plate. It's circular.

Front 23

What are two functions of the orbital septum?

Back 23

Holds fat in place and barrier against infection.

Front 24

What is the function of the muscle pulleys and check ligaments?

Back 24

Stabilizes muscles and prevent overreaction (especially MR)

Front 25

What is found inferiorly that supports the globe?

Back 25

Suspensory ligaments of Lockwood.

Front 26

What is a barrier to infection of the globe?

Back 26

Tenon's capsule.

Front 27

What is the sarcolemma?

Back 27

Plasma membrane that surrounds each of the muscle fibres and passes action potentials along the cell to stimulate muscles.

Front 28

Is myosin thicc or thin?

Back 28

dum thiccccc

Front 29

Actin is thicc or thin?

Back 29

thin

Front 30

Where do troponin and tropomyosin lie?

Back 30

within grooves of actin

Front 31

What is the A band?

Back 31

Myosin fibre with some actin

Front 32

What is the H zone?

Back 32

Central zone, only contains myosin

Front 33

What is the I band?

Back 33

Light, made of actin only

Front 34

What is the Z line?

Back 34

bisects I band attachment for actin

Front 35

What are two characteristics of EOMs?

Back 35

Denser blood supply and densely innervated. This allows for finer motor control, high velocity of movement accuracy.

Front 36

What is the global layer of EOM responsible for?

Back 36

Movement

Front 37

What is the orbital layer of EOM responsible for?

Back 37

Stabilizes and acts as a muscle pulley.

Front 38

Which two muscles also attach to the dural sheath of the optic nerve?

Back 38

MR and SR

Front 39

What is the order of the muscles from inner to outer on the spiral of tillaux?

Back 39

MILS

Front 40

What is the origin, insertion, pathway and innervation for MR

Back 40

O: OAZ/optic nerve sheath

I: 5.5mm from limbus

Path: Parallel medial wall-->CT pulley then follows globe.

Nerve: CN 3 (inferior division)

Front 41

O, I, Path, Nerve for LR

Back 41

O: AOZ/greater wing of sphenoid.

I: 6.9mm from limbus

Path: Lateral wall then CT pulley, then follows globe.

Nerve: CN 6 (Abducens)

Front 42

O, I, Path, Nerve for SR:

Back 42

O: AOZ/optic nerve sheath

I: 7.7mm from limbus

Path: Beneath levator, they share a sheath. Parallels roof then CT Pulley then follows globe.

Nerve: CN3 (superior)

Front 43

O, I, Path, Nerve for IR:

Back 43

O: AOZ

I: 6.5mm from limbus

Path: IR sheath-->Inferior tarsal plate.

Nerve: CN3 (inferior)

Front 44

O, I, Path, Nerve for SO:

Back 44

O: Anatomical: Lesser wing of sphenoid Effective: trochlea

I: Super posterior lateral position on globe.

Path: Passes anterior to trochlea, poster to insertion. **Lies inferior to SR**

Nerve: CN 4

Front 45

O, I, Path, Neve for IO:

Back 45

O: Medial orbital floor (maxillary)

I: Posterior lateral inferior globe

Path: Medial inferior orbit to lateral globe.

Nerve: CN 3 (inferior)

Front 46

What is the function of the CT pulleys?

Back 46

Act as functional origin of the muscles.

Front 47

What are three functions of CT pulleys?

Back 47

May changes the function of the rectus muscles in tertiary gaze.

Refine coordination of muscle movements

Prevents sideslip of the rectus muscles when the eye moves to secondary gaze.