The Orbit And The Eye Part 1

Front 1

the eyelids are covered internally by___(which is continuous with__)?

Back 1

palpebral conjunctivum (which is continuous with the bulbar conjunctivum)

Front 2

___form the "skeleton of the eyelids?

Back 2

tarsal plates (dense fibroeleastic tissue)

Front 3

what are tarsal plates?

Back 3

dense fibroelastic tissue that form the "skeleton" of the lids

Front 4

what forms the muscular portion of the lids? what is it innervated by?

Back 4

the orbiularis oculi ; innervated by the facial nerve (CN VII)

Front 5

what muscle is involved in the blink reflex?

Back 5

the orbicularis oculi (innervated by the facial nerve)

Front 6

what lubricates the edges of the eyelids?

Back 6

tarsal, meibomian, glands

Front 7

what is the corneal reflex?

Back 7

reflex that protects the eye:

-stimulus to cornea carried in afferent axons in the trigeminal nerve (CN V)

-efferent axons in the facial nerve contract orbicularis oculi muscle

Front 8

loss of the corneal reflex with ___injury, causes?

Back 8

with facial nerve injury causes corneal damage and ulceration

Front 9

what muscle elevates the eyelids? and what is it innervated by?

Back 9

levator palpebrae superioris muscle; innervated by the oculomotor nerve (III)

Front 10

Muller's muscle is ___muscle? it is innervated by? and paralysis causes?

Back 10

-is smooth muscle

-innervated by postganglionic sympathetics from the superior cervical ganglion

-paralysis causes ptosis or drooping of the upper lid (part of Horner's Syndrome)

Front 11

tears from the lacrimal gland contain?

Back 11

lysozyme and IgA

Front 12

tear production in the lacrimal gland is controlled by? the lacrimal gland also has __innervation?

Back 12

tear production controlled by parasympathetic innervation from facial nerve (VII)

-also sympathetics

Front 13

the tear film ___out of the lacrimal gland?

Back 13

continues

Front 14

tears from the lacrimal gland drain into ___and via ___into lacrimal sac that empties via ___into__?

Back 14

drain into lacrimal puncta and via caniliculi into lacrimal sac that empties via nasolacrimal duct into inferior nasal meatus

Front 15

what make up the four walls of the orbit?

Back 15

superior- orbital portion of frontal bone

medial- mostly ethmoid bone

inferior- mainly maxillary bone w/ contributions from zygomatic and palatine bones

lateral- frontal portion of zygomatic bone and greater wing of the sphenoid bone

Front 16

where is the apex of the orbit located?

Back 16

at the optic canal in the lesser wing of the sphenoid

Front 17

what are the angles of the walls of the orbit and the orbital axes?

Back 17

-medial walls are parallel, one to another

-lateral walls are approx at right angle to one another

-orbital axes diverge at 45 degrees

Front 18

in orbital blowout fractures, the thin walls allow fractures that can involve?

Back 18

involve the sinuses

Front 19

medial wall orbital blow fractures can involve the __?

injury to the floor can involve the___?

damage to the roof can involve?

Back 19

medial- ethmoid sinuses

floor- maxillary sinus

roof- frontal lobe of the brain

Front 20

after an orbital blowout fracture, bleeding into the orbit may cause?

Back 20

eye to protrude, this is called exopthalmos

Front 21

orbital contents?

Back 21

periorbita (periosteum)

orbital fat

nerves and vessels

extraoccular muscles

eye (bulbus oculi)

lacrimal apparatus

Front 22

orbital fat functions?

Back 22

-padding

-allows eye movements

Front 23

what is the major blood supply to the orbit? and its a branch of?

Back 23

the opthalmic artery

-first branch of internal carotid artery

Front 24

one of the smallest branches off the opthalmic artery is the ___, occlusion of which can cause?

Back 24

is the central artery of the retina, occlusion of which can cause blindness in that eye

Front 25

the opthalmic artery gives off what branches and where do they go?

Back 25

-central retinal a. that enters optic n. to get to the retina

-posterior ciliary arteries penetrate sclera to supply choroid and outer retina (pigment epithelium and rods and cones)

Front 26

what four muscles arise from the tendinous ring and what is there function?

Back 26

-lateral rectus--abduction

-inferior rectus--downward gaze

-medial rectus-- abduction

-superior rectus--upward gaze

Front 27

oculomotor nerve (CN III) innervates the levator palpebrae superiors as well as what extrinsic eye muscles?

Back 27

superior rectus, medial rectus, inferior rectus, inferior oblique

Front 28

the trochlear nerve (CN IV) innervates what extrinsic eye muscles?

Back 28

superior oblique

Front 29

the abducens nerve (CN VI) innervates what extrinsic eye muscles?

Back 29

lateral rectus (abducts the eye)

Front 30

angle of gaze coinciding with angle of superior rectus?

Back 30

-elevation only

23 degrees

Front 31

angle of gaze coinciding with angle of inferior rectus?

Back 31

-depression only

23 degrees

Front 32

angle of gaze coinciding with angle of superior oblique?

Back 32

-depression only

51 degrees

Front 33

angle of gaze coinciding with angle of inferior oblique?

Back 33

-elevation only

51 degrees

Front 34

to test the extrinsic muscles of the eye individually, you must ___?

Back 34

you must line the axis of the eyeball with the axis of muscle pull

Front 35

to test the muscles individually you must line the axis of the eyeball with the axis of the muscle pull, to do this for the superior and inferior recti, you?

Back 35

you ask patient to look laterally, i.e. abduct the eye being tested

Front 36

to test the muscles individually, you must line the axis of the eyeball with the axis of muscle pull, to do this for the obliques, you?

Back 36

you ask the patient to adduct the eye being tested

Front 37

when muscle testing the superior and lateral rectus, you have the patient look ___, then __for superior rectus, and ___for inferior rectus?

Back 37

look laterally, then

-up for superior rectus

-down for inferior rectus

Front 38

when muscle testing the superior oblique and inferior oblique, you ask the patient to look ___, then __for inferior oblique, and ___for superior oblique?

Back 38

look medially, then up for inferior oblique, and down for superior oblique

Front 39

with regards to muscle testing, ___are self evident?

Back 39

medial and lateral recti are self evident

Front 40

abducens palsies affects ____, so when staring straight ahead (primary gaze), affected eye is __by__?

Back 40

-affects lateral gaze

-affected eye pulled medially by unopposed medial rectus

Front 41

trochlear palsy causes ___, which makes the affected eye __?

Back 41

causes hypertropia-- affected eye looks upward when patient asked to stare ahead

Front 42

with trochlear palsy, patient suffers from ___? the compensate for this , patient ___?

Back 42

-suffers from diplopia

-pt tilts head downwardly away from affected eye to compensate

Front 43

oculomotor palsy affects?

Back 43

4 of 6 extraocular muscles

Front 44

with oculomotor palsy, affected eye___?

Back 44

affected eye stares down and out due to unopposed actions of lateral rectus and superior oblique muscles

Front 45

with oculomotor palsy, patient cannot___? and they have ___? the pupil of the affected side is?

Back 45

-patient cannot elevate upper lid

-cannot stare at object as it is moved toward face (impaired adduction)

-diplopia

-pupil of affected side dilated due to unopposed action of sympathetics on dilator pupillae muscle