Orbit

Front 1

Bones of the Orbit

Back 1

Lesser wing of sphenoid
Superior orbital fissure
Greater wing of sphenoid
Frontal bone
Optic Canal
Ethmoidal foramina
Ethmoid Bone

Front 2

The shape of the orbit is almost _____

Back 2

pyramidal

Front 3

Medial walls of the orbit are ____. Lateral walls are __________.

Back 3

parallel; at right angles

Front 4

The orbit is comprised of all or part of ____ bones and lined with_________which forms a funnel shaped fascial sheath that encloses the orbital contents.

Back 4

Seven; periorbita (orbital periosteum)

Front 5

Orbital margin of the orbit

Back 5

Frontal bone
Maxilla
Zygomatic bone

Front 6

Superior wall or roof

Back 6

Frontal bone (orbital plate)
Lesser wing of the sphenoid bone
(Posterior part)

Front 7

Medial wall of orbit

Back 7

a. Ethmoid - lamina papyracea
b. Frontal bone
c. Lacrimal bone
d. Sphenoid bone

Front 8

Inferior wall - or Floor; separated from lateral wall by the inferior orbital fissure

Back 8

a. Maxilla - orbital surface
b. Zygomatic bone
c. Palatine bone – (orbital process)

Front 9

Lateral Wall of orbit

Back 9

a. Zygomatic bone - frontal process
b. Sphenoid bone - greater wing

Front 10

Orbital margin fractures

Back 10

fractures at the suture

Front 11

Blowout fractures

Back 11

medial and inferior walls are thin and may fracture while the margin remains intact

Front 12

Superior wall is ________ but still thin and can be penetrated by sharp objects. Problematic because it is directly related to the _______.

Back 12

stronger; frontal lobe

Front 13

Openings into the Orbit

Back 13

Superior orbital fissure
Inferior orbital fissure
Optic Canal

Front 14

Optic Canal

Back 14

- transmits optic nerve (CN II), ophthalmic artery

Front 15

Superior Orbital Fissure

Back 15

- transmits oculomotor nerve (CN III), trochlear nerve (CN IV), ophthalmic division of trigeminal nerve (CN V1), abducens nerve (CN VI) and superior ophthalmic vein

Front 16

Inferior orbital fissure

Back 16

- transmits maxillary division of the trigeminal nerve (CN V2) and the infraorbital artery and vein

Front 17

Soft tissues of the orbit are called

Back 17

the eyelids

Front 18

Soft tissues of the orbit include

Back 18

Skin
Tela subcutanea
Orbicularis oculi muscle
Fibrous layer (for upper lid)
Conjunctiva
Muscles responsible for opening and closing palpebral fissure

Front 19

SKin of the orbit

Back 19

thin, delicate and transparent

Front 20

Tela Subcutanea of the orbit

Back 20

loose, allows accumulation of fluid (edema or “black eye”)

Front 21

Orbicularis oculi muscle

Back 21

1. Closes palpebral fissure
2. Muscle of facial expression

Front 22

Muscle of facial expression of the orbit

Back 22

a. Palpebral part
b. Orbital part
c. Lacrimal part

Front 23

Fibrous Layer (described for upper lid) of the orbit

Back 23

1. Orbital septum
2. Aponeurosis of levator palpebrae superioris muscle
3. Superior tarsal muscle
4. Tarsal plate

Front 24

Orbital septum

Back 24

continuous with the periorbita inside the orbit and the periosteum covering frontal bone
Part of the fibrous layer of the orbit

Front 25

Aponeurosis of levator palpebrae superioris muscle

Back 25

part of the fibrous layer of the orbit

Front 26

Superior tarsal muscle

Back 26

smooth muscle innervated by sympathetic n.s.
part of the fibrous layer of the orbit

Front 27

What is the major support for the eyelid?

Back 27

Tarsal plate

Front 28

Tarsal plate

Back 28

a. major support for the eyelid
b. plate of dense connective tissue anchored to the anterior lacrimal crest medially and the orbital tubercle of zygomatic bone laterally
c. embedded within it is the tarsal gland (responsible for increasing the viscosity of tears and decreasing their evaporation
Part of the fibrous part of the orbit

Front 29

Conjunctiva of the eye

Back 29

1. Palpebral conjunctiva- continuous with bulbar conjunctiva at superior and inferior conjunctival fornices)
2. Orbital (bulbar) conjunctiva
3. Conjunctival fornix - junction of palpebral and orbital (bulbar) conjunctivae

Front 30

Palpebral conjunctiva

Back 30

continuous with bulbar conjunctiva at superior and inferior conjunctival fornices)

Front 31

Conjunctival fornix

Back 31

junction of palpebral and orbital (bulbar) conjunctivae

Front 32

Conjunctivitis

Back 32

conjunctiva is colorless except when vessels are dialated/congested; conjunctivitis results from bacterial or viral infections or severe allergies

Front 33

Subconjunctival hemorrhage

Back 33

can occur due to injury/inflammation

Front 34

Muscles responsible for opening palpebral fissure.

Back 34

a. Levator palpebrae superioris - comprised of skeletal muscle; innervated by Cranial Nerve III
b. Superior tarsal muscle - comprised of smooth muscle; innervated by sympathetic nervous system; see section VIII - Smooth Muscle of the Orbit

Front 35

Levator palpebrae superioris

Back 35

comprised of skeletal muscle; innervated by Cranial Nerve III

Front 36

Superior tarsal muscle

Back 36

comprised of smooth muscle; innervated by sympathetic nervous system; see section VIII - Smooth Muscle of the Orbit

Front 37

Closure of the eyelid is done by _____ ____.

Back 37

orbicularis oculi - comprised of skeletal muscle; innervated by Cranial Nerve VII

Front 38

Orbicularis oculi is innervted by

Back 38

Cranial nerve VII

Front 39

Lacrimal Apparatus includes

Back 39

A. Lacrimal gland
B. Lacrimal Puncta
C. Lacrimal Canaliculi
D. Lacrimal Sac
E. Nasolacrimal Duct
F. Lacrimal Gland Secretion

Front 40

Lacrimal Gland

Back 40

1. Located in lateral aspect of the orbit posterior to the orbital septum
2. Curves around lateral edge of aponeurosis of levator palpebrae superioris muscle
3. Tears are secreted into the superior fornix of conjunctival sac and washed across the eyeball to the lacrimal lake to then enter:
B. Lacrimal Puncta
C. Lacrimal Canaliculi
D. Lacrimal Sac
E. Nasolacrimal duct

Front 41

Tears are secreted into the ________ of conjunctival sac and washed across the eyeball to the lacrimal lake to then enter:

Back 41

superior fornix


B. Lacrimal Puncta
C. Lacrimal Canaliculi
D. Lacrimal Sac
E. Nasolacrimal duct

Front 42

Nasolacrimal duct

Back 42

Connects lacrimal sac to the inferior meatus

Front 43

Lacrimal Gland Secretion is a result of stimulation of _______.

Back 43

postganglionic parasympathetic fibers in lacrimal n.

Cell bodies: pterygopalatine ganglion
Preganglionic parasympathetic fibers have their cell bodies in the superior salivatory nucleus and leave the brainstem in the facial nerve (CN VII).

Front 44

Cell bodies of Lacrimal gland secretion are located in

Back 44

pterygopalatine ganglion

Front 45

Preganglionic parasympathetic fibers have their cell bodies in the________ and leave the brainstem in the ______.

Back 45

superior salivatory nucleus; facial nerve (CN VII

Front 46

Superior Oblique muscle is innervated by the ______ and the cell bodies are in the ____

Back 46

the Trochlear N; Trochlear nucleus

Front 47

The origin of the superior oblique muscle is

Back 47

the body of the sphenoid

Front 48

The Lateral Rectus muscle is innervated by the ___ and the cell bodies are in the ____

Back 48

Abducens N; Abducens nuclues

Front 49

The levator palpebrae superioris is innervated by the _____ and the cell bodies are located in the _____.

Back 49

Oculomotor N; oculomotor nucleus

Front 50

The inferior rectus, medial rectus, superior rectus, levator palpebrae superioris, and inferior oblique muscles are all innervated by the _____ and the cell bodies are in the _____

Back 50

Oculomotor N; oculomotor nucleus

Front 51

The origin of the levator palpebrae superioris muscle is the

Back 51

lesser wing of sphenoid

Front 52

The origin of the inferior rectus muscle, medial rectus muscle, and superior rectus muscle is the

Back 52

common tendinous ring

Front 53

The origin of the inferior oblique muscle is the

Back 53

anterior floor of orbit

Front 54

Medial rectus muscle functions only in

Back 54

adduction

Front 55

Lateral rectus muscle functions only in

Back 55

abduction

Front 56

Primary and secondary action of superior rectus m.

Back 56

P-elevation
S-adduction

Front 57

Primary and secondary action of the inferior rectus

Back 57

p-depression
s-adduction

Front 58

Inferior oblique primary and secondary action

Back 58

p-elevation
s-abduction

Front 59

Superior oblique muscle primary and secondary action

Back 59

p-depression
s-abduction

Front 60

Testing of Extraocular Muscles

Back 60

1. Each muscle is examined at its position of greatest efficiency
2. The medial and lateral recti can be tested easily for their single actions
3. The other four muscles must be specially positioned so that the muscle being tested is the only muscle capable of performing the required primary action.
a. Eye abducted - superior rectus elevates, inferior rectus depresses
b. Eye adducted - inferior oblique elevates, superior oblique depresses

Front 61

Eye abducted (what muscles)?

Back 61

superior rectus elevates, inferior rectus depresses

Front 62

Eye adducted (what muscles)?

Back 62

inferior oblique elevates, superior oblique depresses

Front 63

Arterial supply to the orbit and eyeball includes

Back 63

branch of internal carotid
branches of ophthalmic artery
1. Posterior ethmoidal
2. Anterior ethmoidal
3. Dorsal nasal
4. Supratrochlear
5. Supraorbital
6. Central artery of the retina - an end artery
7. Ciliary arteries - long and short posterior ciliary arteries
8. Lacrimal
9. Palpebral arteries


infraorbital A.

Front 64

branches of Ophthalmic A that supply orbit and eyeball

Back 64

1. Posterior ethmoidal
2. Anterior ethmoidal
3. Dorsal nasal
4. Supratrochlear
5. Supraorbital
6. Central artery of the retina - an end artery
7. Ciliary arteries - long and short posterior ciliary arteries
8. Lacrimal
9. Palpebral arteries-to supply the upper and lower lids

Front 65

Veins of the orbit communicate with the dural venous sinuses (via the cavernous sinus), with the _____, and with the veins of the face via the _____

Back 65

pterygoid plexus; angular vein

Front 66

Veins of the orbit

Back 66

1. Supraorbital vein
2. Infraorbital vein
3. Superior ophthalmic vein
4. Inferior ophthalmic vein

Front 67

Nerves of the orbit

Back 67

A. Optic (CN II)
B. Oculomotor (CN III)
1. Superior Division: levator palpebrae superioris, superior rectus
2. Inferior Division: medial rectus, inferior oblique and inferior rectus
C. Trochlear (CN IV)
D. Ophthalmic - V1 (sensory)
1. Frontal nerve
a. supraorbital
b. supratrochlear
2. Nasociliary nerve
3. Anterior ethmoid
4. Infratrochlear
5. Long ciliary
6. Short ciliary
E. Abducens (CN VI)

Front 68

What muscles does the superior division of the oculomotor N innervate?

Back 68

levator palpebrae superioris, superior rectus

Front 69

What muscles does the inferior division of the oculomotor N innervate?

Back 69

medial rectus, inferior oblique and inferior rectus

Front 70

The three-layered sphere of the eyeball contain what three structures?

Back 70

Fibrous coat (sclera and cornea)
Vascular coat (choroid, ciliary body, and iris)
Retina

Front 71

The fibrous coat of the eyeball contains

Back 71

a. Sclera - opaque posterior 5/6; provides shape, resistance, attachment for extraocular muscles and intrinsic muscles of the eye; “white of the eye”
b. Cornea - transparent anterior 1/6

Front 72

Sclera is located in what part of the fibrous coat of the eyeball

Back 72

opaque posterior 5/6; provides shape, resistance, attachment for extraocular muscles and intrinsic muscles of the eye; “white of the eye”

Part of the fibrous coat of the eyeball

Front 73

Cornea is located in what part of the fibrous coat of the eyeball

Back 73

transparent anterior 1/6

part of fibrous coat of eyeball

Front 74

Vascular coat(uvea) contains

Back 74

a. Choroid-between the slera and retina; firmly attached to retina and engorged with blood
b. Ciliary body - suspensory mechanism for lens, ciliary muscle controls shape of lens and thus, focus; ciliary processes secrete aqueous humor
c. Iris - muscular diaphragm to control light entrance; central aperature is the pupil

Front 75

Choroid

Back 75

between the slera and retina; firmly attached to retina and engorged with blood

part of vascular coat

Front 76

Ciliary body

Back 76

suspensory mechanism for lens, ciliary muscle controls shape of lens and thus, focus; ciliary processes secrete aqueous humor

vascular coat of eyeball

Front 77

iris

Back 77

muscular diaphragm to control light entrance; central aperature is the pupil

part of vascular coat of eyeball

Front 78

Retina

Back 78

a. inner layer
b. two parts:
1 optic: light sensitive; terminates along ora serrata
2. non-visual: fundus at posterior part of the eyeball; optic disc –sensory fibers and vessels conveyed by optic nerve enter ; insensitive to light

Front 79

Refractive media of the eyeball includes

Back 79

cornea
aqueuous humor
lens
vitreous body

Front 80

Cornea

Back 80

- transparent due to regular arrangement of collagen fibers and dehydrated state ; sensitive to touch; avascular, nourished by the aqueous humor and lacrimal fluid

Front 81

Aqueous humor

Back 81

made by ciliary processes; provides nutrients to the cornea and lens ; drains to the scleral venous sinus

Front 82

lens

Back 82

a. posterior to iris and anterior to vitreous humor/body
b. transparent, biconvex
c. elastic capsule anchored by zonular fibers to ciliary body and encircled by ciliary processes; contraction of smooth muscle in the ciliary body reduces tension on lens and it rounds up for near vision (accommodation)

Front 83

Vitreous body

Back 83

transmits light and holds retina in place; supports lens

Front 84

Corneal abrasions/lacerations

Back 84

foreign objects produce corneal abrasions

Front 85

Glaucoma

Back 85

a. drainage of aqueous humor thru sclera venous sinus is decreased; pressure builds in anterior and posterior chambers
b. can lead to blindness if pressure isn’t reduced.

Front 86

Cataracts

Back 86

loss of transparency in lens; results in areas of opaqueness

Front 87

Hemmorhage into the anterior chamber

Back 87

result of blunt force trauma to eye

Front 88

Retinoblastoma

Back 88

a. rare childhood cancer
b. can be unilateral or bilateral
c. most common sign: visible whiteness of normally black pupil in flash photography
d. Prototype of cancer with a genetic component: RB1 gene on Chromosome 13q.

Front 89

Ciliary muscle

Back 89

1. Action: narrows diameter of the ring formed by the ciliary body, releasing tension on the zonular fibers which, in turn, increases the curvature of the lens for near vision (accommodation).
2. Innervation: parasympathetic
3. Preganglionic nerves: nucleus of Edinger-Westphal, travel with the oculomotor nerve (III) to the ciliary ganglion
4. Ganglion: ciliary ganglion (comprised of cell bodies of parasympathetic postganglionic neurons which innervate the ciliary muscle and sphincter pupillae muscle)
5. Postganglionic nerves: short ciliary nerves

Front 90

Action of ciliary muscle

Back 90

narrows diameter of the ring formed by the ciliary body, releasing tension on the zonular fibers which, in turn, increases the curvature of the lens for near vision (accommodation).

Front 91

Innervation of ciliary muscle

Back 91

parasympathetic

Front 92

Ciliary muscle preganglionic nerves

Back 92

nucleus of Edinger-Westphal, travel with the oculomotor nerve (III) to the ciliary ganglion

Front 93

Ciliary muscle ganglion

Back 93

:ciliary ganglion (comprised of cell bodies of parasympathetic postganglionic neurons which innervate the ciliary muscle and sphincter pupillae muscle)

Front 94

Ciliary muscle postganglionic nerves

Back 94

short ciliary nerves

Front 95

Sphincter pupillae muscle

Back 95

1. Action: constricts the pupil
2. Innervation: parasympathetic
3. Preganglionic nerves: nucleus of Edinger-Westphal, travel with the oculomotor nerve (III) to the ciliary ganglion
4. Ganglion: ciliary ganglion (comprised of cell bodies of parasympathetic postganglionic neurons which innervate the ciliary muscle and sphincter pupillae muscle)
5. Postganglionic nerves: short ciliary nerves

Front 96

Action of sphincter pupillae muscle

Back 96

constricts the pupil

Front 97

Innervation of sphincter pupillae muscle

Back 97

parasympathetic

Front 98

Preganglionic nerves of Sphincter pupillae m.

Back 98

nucleus of Edinger-Westphal, travel with the oculomotor nerve (III) to the ciliary ganglion

Front 99

Ganglion of sphincter pupillae m.

Back 99

ciliary ganglion (comprised of cell bodies of parasympathetic postganglionic neurons which innervate the ciliary muscle and sphincter pupillae muscle)

Front 100

Sphincter pupillae m. postganglionic nerves

Back 100

short ciliary nerves

Front 101

Dilator pupillae muscle

Back 101

1. Action: enlarges the pupil
2. Innervation: sympathetic
3. Preganglionic nerves: intermediolateral cell column of upper thoracic levels
4. Ganglion: superior cervical ganglion
5. Postganglionic nerves: pass through the ciliary ganglion (without synapsing) and travel to the eye via the short ciliary nerves
Note: The superior tarsal muscle in the upper eyelid is also innervated by sympathetic nerves.

Front 102

Action of dilator pupillae muscle

Back 102

enlarges the pupil

Front 103

Innervation of dilator pupillae muscle

Back 103

sympathetic

Front 104

Preganglionic nerves of dilator pupillae m.

Back 104

intermediolateral cell column of upper thoracic levels

Front 105

Ganglion of dilator pupillae m.

Back 105

superior cervical ganglion

Front 106

Postganglionic nerves of dilator pupillae m.

Back 106

pass through the ciliary ganglion (without synapsing) and travel to the eye via the short ciliary nerves
Note: The superior tarsal muscle in the upper eyelid is also innervated by sympathetic nerves.

Front 107

The ciliary ganglion will have sensory fibers from nasociliary branches (V1), postganglionic sympathetic fibers from the ____, and preganglionic parasympathetic fibers from the ____. ONLY THE PREGANGLIONIC PARASYMPATHETIC FIBERS SYNAPSE IN THE CILIARY GANGLION.

Back 107

carotid plexus; oculomotor nerve

Front 108

Pupillary Light Reflex

Back 108

1. Light enters one eye and both pupils constrict because each retina sends fibers to the optic tract on both sides of the eye
2. One of the first signs of compression of the ophthalmic nerve is ipsilateral slowness of the papillary response to light

Front 109

Horner Syndrome

Back 109

interruption of the cervical sympathetic trunk resulting in absence of sympathetic functions on the ipsilateral side of the head.
Signs include:
-constriction of the pupil
-ptosis
-redness of skin and increased temperature of skin
-absence of sweating

Front 110

What part of the orbit allows accumulation of fluid (edema or 'black eye')

Back 110

tela subcutanea

Front 111

what is the major support for the eyelid?

Back 111

tarsal plate