LECTURE: Orbit Flashcards
(92 cards)
1
Q
What sinuses lie between the orbits?
A
ethmoid
2
Q
The contents of the orbit are surrounded by
A
bone and orbital fascia
3
Q
What makes up the bony orbital walls? (4)
A
- Medial: ethmoid bone, maxillary bone and lacrimal bone
- Floor: maxillary bone.
- Lateral: sphenoid bone and zygomatic bone.
- Roof: frontal bone.
4
Q
What are the openings in and around the orbit? (5)
A
- supraorbital foramen
- infraorbital foramen
- superior orbital fissure
- inferior orbital fissure
- optic canal
5
Q
What travels through the superior orbital fissure?
A
III, IV, V1, VI
6
Q
What travels through the optic canal?
A
optic nerve and opthalmic artery
7
Q
colored part of eye
A
iris
8
Q
white wall of eye
A
sclera
9
Q
opening in iris
A
pupil
10
Q
small mass of mucous membrane at medial corner of eye
A
lacrimal caruncle
11
Q
small openings above and below caruncle for collection of tears
A
lacrimal puncta
12
Q
A
13
Q
produces tears
A
lacrimal gland
14
Q
transports tears to lacrimal sac
A
lacrimal canaliculi
15
Q
collects tears
A
lacrimal sac
16
Q
drains tears into nasal cavity
A
nasolacrimal duct
17
Q
A
18
Q
connective tissue plates that give the eyelids support
A
tarsi
19
Q
transparent anterior surface of eye
A
cornea
20
Q
focuses incoming light onto retina
A
lens
21
Q
posterior lining of eye with specialized photoreceptors
A
retina
22
Q
cavity located posterior to lens
A
posterior cavity
23
Q
transparent, gelatinous substance within posterior cavity
A
vitreous body
24
Q
space anterior to lens
A
anterior cavity
25
space between cornea and iris
anterior chamber
26
space between iris and lens
posterior chamber
27
clear, watery fluid in anterior cavity
aqueous humor
28
29
circular smooth muscle that affects shape of lens
ciliary muscle
30
connects ciliary muscle to capsule of lens
suspensory ligament
31
circular smooth muscle that affects size of pupil
sphincter pupillae
32
drains fluid from anterior cavity
canal of Schlemm
33
Blockage of the canal of Schlemm leads to what?
glaucoma
34
mucous membrane of anterior eye and eyelids
conjunctiva
35
skeletal (voluntary) muscle that elevates the upper eyelid
levator palpebrae superioris
36
superior tarsal (Muller’s) muscle helps with what?
elevation of upper eyelid
37
Parasympathetic innervation makes the pupil …
contract
38
Sympathetic innervation makes the pupil …
dilate
39
What ligaments pull on the lens to make it thinner?
suspensory ligaments
40
During relaxation of ciliary muscle, the suspensory ligaments are …
pulling on the lens, causing it to become thinner
41
During contraction of the ciliary muscle, suspensory ligaments are …
slacking, reducing the pull on the lens and allows it to become thicker
42
Describe lens shape for distant vision
43
Describe lens shape for near objects
44
depression in retina that represents the area of greatest visual acuity
fovea
45
There are how many extraocular muscles which move the eyeball, and a muscle that elevates the upper eyelid?
6
46
Classify the 6 extraocular muscles
4 rectus
2 oblique
47
48
Which eye muscle runs from the common tendinous ring to the superior aspect of the eyeball?
superior rectus
49
Contraction of this muscle causes the eyeball to elevate and adduct (move superiorly and medially).
superior rectus
50
Which eye muscle runs from the common tendinous ring to the inferior aspect of the eyeball?
inferior rectus
51
Contraction of this muscle causes the eyeball to depress and adduct (move inferiorly and medially).
inferior rectus
52
Which eye muscle runs from the common tendinous ring to the medial aspect of the eyeball?
medial rectus
53
Contraction of this muscle causes the eyeball to move inward, or adduct.
medial rectus
54
Which eye muscle runs from the common tendinous ring to the lateral aspect of the eyeball?
lateral rectus
55
Contraction of this muscle causes the eyeball to move outward, or abduct.
lateral rectus
56
All rectus muscles are innervated by what nerves?
CN III except for lateral rectus which is innervated by CN IV (abducens)
57
Which eye muscle runs from the body of the sphenoid bone (just superiomedial to common tendon) to the superior region of the eyeball?
superior oblique
58
Which eye muscle runs in the medial aspect of the superior orbit before looping around a tendinous trochlea (pulley) in the anterior/medial orbit, changing its angle of attachment?
superior oblique
59
Contraction of this muscle causes the eyeball to depress and abduct (inferior and lateral).
superior oblique
60
Which eye muscle runs from the anterior part of the floor of the orbit, medially, to the inferior aspect of the eyeball?
inferior oblique
61
It causes the eye to elevate and abduct (superior and lateral).
inferior oblique
62
Superior oblique is innervated by what nerve?
CN IV
63
The inferior oblique is innervated by what nerve?
CN III
64
Which muscle runs from the lesser wing of sphenoid bone, near optic canal, to the superior tarsus (upper eyelid)?
levator palpebrae superioris
65
Which nerve carries visual information from retina?
CN II (optic nerve)
66
The lateral half of each retina projects to the ______ of the brain while the medial half projects to the _____ side.
lateral = same side
medial = opposite side
67
The _________ contains crossing fibers.
optic chiasm
68
Where would the lesion be located?
R optic nerve lesion
69
Where would the lesion be located?
optic chiasm lesion
70
Where would the lesion be located?
R optic tract lesion
71
Which nerve carries parasympathetics to the smooth muscle of the lens and pupil?
CN III (oculomotor)
72
The parasympathetics synapse in the ciliary ganglion and then to eyeball via what nerve?
ciliary nerves
73
V1 splits into which nerves?
* frontal nerve
* nasociliary nerve
* lacrimal nerve
74
Which nerve splits into supraorbital and supratrochlear nerves which carry sensation from the forehead?
frontal nerve
75
Which nerve gives rise to anterior and posterior ethmoidal branches before exiting the orbit as the infratrochlear nerve?
nasociliary nerve
76
The ethmoidal nerves handle sensation from (3)
ethmoid air cells (sinuses), nasal cavity and bridge of nose (via the external nasal nerve)
77
Infratrochlear nerve carries sensation from
skin around medial eye
78
Which nerve carries sensation from the cornea?
nasociliary nerve
79
Carries sensation from skin outside the eye
lacrimal nerve
80
The cell bodies of V1 neurons are in the …
trigeminal ganglion
81
Short ciliary nerves vs. long ciliary nerves
* Short ciliary nerves: sympathetic, parasympathetic **and** general sensory
* long ciliary nerves: sympathetic and sensory
82
Although the maxillary division of the trigeminal nerve (V2), does nothing in the orbit, it gives rise to the ______ in the lateral orbit, and then travels along the floor as the infraorbital nerve.
zygomatic nerve
83
V2 receives sensation from skin of the face through what nerves?
zygomaticotemporal, zygomaticofacial and infraorbital nerves
84
V2 carries sensation from the maxillary teeth through what nerve?
superior alveolar nerves
85
The main artery of the orbit
ophthalmic artery
86
The ophthalmic artery is a branch of what artery?
internal carotid artery
87
The ophthalmic artery travels through the ______ with the optic nerve and gives rise to 6 branches.
optic foramen
88
What are the branches of the ophthalmic artery? (6)
1. lacrimal
2. supraorbital
3. supratrochlear
4. anterior/posterior ethmoidal
5. ciliary
6. central artery of the retina
89
What vein drains blood from the orbit?
ophthalmic vein
90
Superior and inferior ophthalmic veins empty into what posteriorly?
cavernous sinus
91
Superior and inferior ophthalmic veins empty into what inferiorly?
pterygoid plexus of veins
92
What provides a pathway for spread of infection from face to venous sinuses?
communication of angular (facial) vein and ophthalmic veins
