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Flashcards in The Orbit Deck (137):
1

What are the 7 bones that for the orbital surfaces

frontal bone
sphenoid
maxilla
palatine
lacrimal
ethmoid
zygomatic

2

What is contained within the optic canal

CN2, and opthalmic artery

3

What bone is associated with the optic canal

lesser wing of the sphenoid

4

What are the contents of the superior orbital fissure

CN3, CN4, CN6, V1, and superior opthalmic veins

5

What bones are associated with the superior orbital fissure

lesser and greater wings of sphenoid

6

What are the contents of the inferior orbital fissure

infraorbital n,a,v

7

What are the contents of the supraorbital foramen

supraorbital n,a,v

8

What are the contents of the infraorbital foramen

infraorbital n,a,v

9

What is the infraorbital foramen continuous with

The infraorbital groove

10

What is contained within the ethmoidal foramina

ethmoidal n,a,v

11

What is contained in the the nasolacrimal canal

the nasolacrimal duct

12

Which part of the orbit is the thickest

the lateral wall

13

What does the medial wall separate

the orbit from the ethmoid air cells and nasal cavity

14

What does the roof separate

Orbit from the anterior cranial fossa

15

What does the floor separate

orbit from the maxillary sinus

16

Where are the canthi located

edges of the palpebral fissure

17

What is another name for the lateral canthus

temporal canthus

18

What is another name for the medial canthus

nasal canthus

19

What structures are included in the medial canthus

Lacrimal Caruncle
Lacrimal Puncta

20

What is the lacrimal caruncle

fleshy prominence at the medial canthus, contains sebaceous and sweat glands

21

What is the lacrimal puncta

found in the lacrimal papilla, its a pinhole opening that permits draining of lacrimal fluid

22

What help to maintain the shape of the eyelids

Tarsal plates-found deep to skin and muscle

23

What glands are found embedded within the tarsal plates

Tarsal Glands (meibonnian gland)

24

What type of gland are tarsal glands

sebaceous-functions
lubricate the margins of eye
increase surface tension along margins

25

What are the ciliary glands

Glands of Moll
Glands of Zeis

26

What type of gland is the gland of moll

sweat gland

27

what type of gland is the gland of zeiss

sebaceous glands

28

What is a Sty

Hordoleum- infected gland of eyelid

29

What is a chalazion

plugged gland -- cyst like

30

What are the two portions of the conjuctiva

Palpebral portion
Bulbar portion

31

What does the palpebral portion of the conjuctiva cover

the internal surface of the eyelids

32

What does the bulbar portion of the conjuctiva do

reflects onto the eyeball--continuous with the outer cornea

33

Where are the fornices and what are they

recesses of the conjuctiva, and they are where the palpebral conjuctiva meet the bulbar conjuctiva

34

Where is the lacrimal gland located

superolateral position of the anterior orbit

35

What does the lacrimal gland do

secretes serous lacrimal fluid (lacrimation) through series of ducts

36

What is the function of the lacrimal gland

Circulate fluid across corneal surface and inner eyelids to:
moisten
clean
lubricate
"protect"

37

Which part of the spinal cord do the preganglionic sympathetic fibers exit

T1-T5

38

What is the function of the parasympathetic fibers innervating the lacrimal gland

secretomotor-- control lacrimation

39

What nerves are associated with the preganglionic parasympathetic fibers of the lacrimal gland

CN7 and greater petrosal nerve

40

What ganglion is associated with postganglionic parasympathetic neurons of the lacrimal gland

Sphenopalatine ganglion

41

What do the sympathetic fibers of the lacrima gland innervate

the arteries of the gland

42

Whats the function of the sympathetic fibers of the lacrimal gland

vasomotor

43

What ganglion is associated with the postganglionic sympathetic fibers of the lacrimal gland

The superior cervical ganglion

44

How does lacrimal fluid move from lacrimal gland to nasal cavity

Lacrimal Puncta
Lacrimal Canaliculi
Lacrimal Sac
Nasolacrimal Duct

45

How does the lacrimal fluid move through the lacrimal sac

its compressed by the action of blinking pushing the fluid through

46

What are the two layers formed from the separation of the cranial dura upon entrance into the orbit

Peri Orbita
Orbiral Dura

47

What is the Peri Orbita and what are the characteristics

Periosteal layer lining the orbit that easily separates from the bones of the orbit

48

What is the orbital dura and what are the characteristics

Outer meningeal layer of the optic nerve
It follows the optic nerve to posterior eyeball where it becomes continuous with the sclera of the eyeball

49

What is the function of the orbital fat

helps maintain orientation of orbital structures
helps to form soft socket for eyeball

50

What is the Tenons Capsule (fascia bulbi)

Smooth thin membranous layer of fascia on anterior edge of the orbital fat (posterior to eyeball)

51

What is the Episcleral Space

The potential space between the sclera and tenons capsule

52

What is formed by the orbital fat, tenons capsule, and the episcleral space

The socket for the eyeball

53

True/False:
There are seven extrinsic muscles of the eyeball and 5 of those muscles move the eyeball

False: 6 move the eyeball and 1 moves the eyelid

54

What is the common tendon that all recti muscles originate from

Annulus Tendineous -- Ring like tendon located at the apex of the orbit near the optic canal and the superior orbital fissure

55

What is the action and innervation of the Lateral Rectus m

CN 6-- pure abduction of the eye

56

What is the innervation and action of the medial rectus muscle

CN3-- fairly pure adduction of eye

57

What is the innervation of the and action of the inferior rectus

CN3-- principle: depression of eye
also: adduction, lateral rotation(extorsion)

58

What is the innervation and action of the superior rectus muscle

CN3-- elevation(principle)
also: adduction, medial rotation (intorsion)

59

What is the origin of the superior oblique muscle

sphenoid above the the annulus tendineous at orbital apex

60

What is the insertion of the superior oblique muscle

passes through trochlea and inserts onto sclera superolaterally

61

What is the trochlea

fibrocartilaginous loop of tissue located on anterosuperomedial aspect of the orbit

62

What is the innervation and action of the superior oblique muscle

CN4-- depression (principle)
also: abduction, medial rotation (intorsion)

63

What is the origin of the inferior oblique muscle

floor of the orbit at the anteromedial aspect

64

Where does the inferior oblique muscle insert

lateral and posterior aspect of the eyeball

65

What are actions of the inferior oblique muscle

elevation (principle)
also: abduction, lateral rotation (extorsion)

66

Why are the medial and lateral recti muscles so important

They produce relatively pure movement, and therefore if paralyzed they would greatly hinder that particular movements

67

Will paralysis of muscles other than lateral and medial recti be noticeable

no since none of them produce a unique movement

68

What are the two types of coordinated movements of the eyes

conjugate: parallel
vergence: divergence, and convergence

69

What is the insertion of the levator palpebral superioris

superior tarsal plate/superior palpebrae

70

What is the innervation and action of levator palpebra superioris

CN3-- elevate the superior eyelid

71

What is the condition when the levator palpebra superioris is paralyzed

Ptosis of the eyelid-- droopy eyelid

72

What are the accessory muscles of the orbit

Tarsal muscles (superior and inferior)

73

What type of muscle are the tarsal muscles

smooth muscle

74

What is the innervation and action of the tarsal muscles

postganglionic sympathetic fibers-- assist in elevating the superior palpebrum and depressing the inferior palpebrum

75

What is opthalmic artery a branch of

the internal carotid

76

Where does the opthalmic artery enter the orbit

through the optic canal travels along medial wall of orbit

77

What are the 7 branches of the opthalmic artery

Central Artery
Lacrimal Artery
Posterior Ciliary Artery
Anterior ciliary a
supraorbital a
ethmoidal a
supratrochlear a

78

What is supplied by the central artery

inner retina

79

What is supplied by the lacrimal artery

elements of lateral orbit
lacrimal glands
lateral eyelids
some skin of lateral orbit

80

What is supplied by the posterior ciliary artery

posterior aspect of eyeball

81

What is the supplied by the anterior ciliary artery

anterior aspect of the eyeball

82

What does the supraorbital artery pass through

supraorbital foramen

83

What is supplied by the supraorbital artery

elements of the superior orbit
cutaneous elements of the upper eyelid and the skin of forehead

84

What is supplied by the ethmoidal arteries

ethmoid air cells
frontal sinus
part of nasal cavity

85

What is the terminal branch of the ophthalmic artery

Supratrochlear artery

86

What is supplied by the supratrochlear artery

top bridge of nose and medial forehead

87

What two branches of the ophthalmic artery supply blood to capillary plexus in choroid layer of eyeball

posterior and anterior ciliary arteries

88

Where does superior ophthalmic vein drain to

through orbit into the cavernous sinus

89

Where does the inferior ophthalmic vein receive blood from

inferior elements of the orbit-- drains into the cavernous sinus

90

Where do the central veins receive blood from and where do they drain to

from the inner retina and drain into ophtalmic veins or directly into cavernous sinus

91

Where do the vortex veins receive blood from and where do they drain to

from the outer layers of the eyeball drain into ophthalmic vv.

92

Is the ophthalmic nerve sensroy or motor fibers

sensory only

93

What are the branches of the ophthalmic nerve

frontal n
lacrimal n
nasociliary n

94

Which branch is the largest branch of the ophthalmic nerve

frontal n

95

What are the 2 branches of the frontal nerve

supratrochlear n
supraorbital n

96

What does the supraorbital nerve innervate

tissue of forehead
help upper eyelid
help conjuctiva

97

What does the supratrochlear nerve innervate

helps upper eyelid
helps conjuctiva

98

What are the branches off the nasociliary nerve

long ciliary nerves
ethmoidal nerves
infratrochlear nerves
nasociliary communicating rami
Hitchhikers

99

What is innervated by the long ciliary nerves

sensory to the eyeball including the cornea and iris

100

What is innervated by the ethmoidal nerves

ethmoid air cells
frontal sinus
PART of the nasal cavity

101

What is innervated by the infratrochlear nerve

sensory to:
skin of medial canthus of the eye
topmost bridge of the nose

102

What does the nasociliary communicating rami communicate with

Ciliary Ganglion

103

What are usually hitchhiking the nasociliary nerves

postganglionic sympathetic fibers from internal carotid nerve plexus

104

What does the lacrimal nerve provide sensory to

conjuctiva
upper eyelid
superior lateral orbit
lacrimal gland

105

Where do the lacrimal n hitchhikers originate from

postganglionic parasympathetic fibers that originate from the sphenopalatine ganglion

106

What type of innervation do the lacrimal n hitchhikers provide

secretomotor to the lacrimal gland

107

Where are the ciliary ganglion located

near the apex of the orbit between the lateral rectus m. and the optic n.

108

How is the ciliary ganglion connected to the back of the eye

short ciliary nerves

109

What is the ciliary ganglion made up of

postganglionic parasympathetic neurons

110

What is innervated by the ciliary ganglion

constrictor pupillae m.
ciliary m.

111

What are the 2 elements of the outer tunic

sclera
cornea

112

What is the sclera continuous with

posteriorly: orbital dura
anteriorly: cornea at the limbus

113

How many layers make up the cornea

3 anterior, middle, inner

114

T/F: The outer tunic is well vascularized

False
Sclera: poorly vascularized
Cornea: largely avascular

115

What are the 3 layers of the middle tunic

choroid
iris
ciliary body

116

What is the major characteristic of the middle tunic of the eye

highly vascularized

117

What supplies the choroid layer of the middle tunic

dense ciliary plexus supplied by ciliary arteries
vortex veins drain the plexus

118

How is the choroid innervated

Nerve plexus supplied by long and short ciliary including:
V1 sensory fibers
postganglionic sympathetic and parasympathetic fibers

119

What complex structure is found in the iris

Pupil

120

What 2 intrinsic muscles control the pupil

sphincter pupillae muscle
dilator pupillae muscle

121

What orientation are the constrictor pupillae mm found

fibers oriented concentrically

122

What innervates the sphincter pupillae muscle

preganglionic CN3
postganglionic neurons of ciliary ganglion

123

What innervates the dilator pupillae muscle

preganglion fibers of T1
postganglion superior cervical ganglion of sympathetic chain

124

What are the two major functions of the ciliary body

Secrete aqueous humor into posterior chamber of the eye
Help suspend the lens and control tension on lens

125

Where is the aqueous humor resorbed

the irido-corneal angle into sinus venous sclerae canal of schlemm

126

What are the functions of aqueous humor

refractive medium of eye
nutrients and fluid to cornea and lens
circulation dynamic helps to establish intraocular pressure

127

What is glaucoma

condition of interference of circulation of aqueous humor -- usually leads to increase in intraocular pressure

128

If the tension on the lens is increased what happens to the shape

the convexity is decreased

129

If the tension on the lens is decreased what happens to the shape

the convexity is increased

130

What are the 2 layers of the inner tunic

neural layer
pigmented layer

131

What is the outermost layer of the inner tunic

the pigmented layer

132

What is the function of the pigmented layer

absorb light through the neural layer
support and provide growth factors to rods and cones

133

What structures are found in the neural layer of the inner tunic

rods and cones -- the proprioceptive cells

134

What is the function of cones

color vision and high resolution

135

What is the function of rods

peripheral vision and low light vision and low resolution

136

What is the order of innervation starting with the rods/cones

bipolar cells--ganglion cells--ganglion cells converge on posterior aspect of the eyeball to form optic nerve at the optic disc-- ora serrata

137

What is the Ora Serrata

anterior serrated edge of functional retina