Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RB Y2 Ophthamology > Anatomy: The Orbit and the Eye > Flashcards

Anatomy: The Orbit and the Eye Flashcards

1
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

where is the optic canal

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how many bones make up the orbit

A

6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the thinnest bone of the optic canal

A

ethmoid - medial wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where is the apex of the bony orbit located

A

nasal side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what bones form the orbital margins

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what forms the orbital rim

A

combiend orbital margins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what function does the orbital rim have in respect to orbital trauma

A

nothing wider than diameter of orbital rim can hit the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe the angle of the orbital rim

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

orbital blowout fracture

A

force on orbital rim damages medial wall (ethmoid) and orbital floor (maxilla) which are extremely thin

can damage the infraorbital NVB resulting in general sensory deficit of facial skin

typically entraps the inferior rectus - patients will complain of pain on upward gaze

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which direction does a fractured zygoma tend to rotate, and what can this result in clinically

A

medially towards orbit floor

as the suspensory ligament of the eye attaches to the zygoma laterally, the eye may be lowered towards the orbital floor

results in diploplia (double vision)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the difference between notch and foramen

A

notch is an incomplete circle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

outer eyelid:

name the 2 parts of the orbicularis oculi

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe the functions of the orbital and paplebral parts of the orbicularis oculi

A

orbital part closes the eye tightly

palpebral part is involved in normal blinking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the orbicularis oculi innervated by

A

CNVII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is another name for the superior tarsal muscle (connective tissue?)

A

Muller’s muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

medial eyelid layer:

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the orbital septum made of and what is its function

A

sheet of fascia

helps to prevent spread of infection from superficial to deep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

inner eyelid layer:

tarsal glands

A

also called Meibomian glands

glands embedded in the tarsal muscles, responsible for lipid secretion

they secrete a layer of oil on top of tears to stop them from evaporating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

tears:

  • antibacterial properties
  • pH
A

antibacterial properties due to action of lysozyme

pH of around 7.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

describe the conjunctiva - 2 types and where they meet

A

the inner surface of the eyelid is lined by palpebral conjunctiva

the eyeball is lined by bulbar conjunctiva

meet at the fornix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

conjunctival fornix

A

connects the conjunctiva lining the inside of the eyelid with that covering the eyeball

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

describe the features of the palpebral conjunctiva

A

has follicles and papillae

contains goblet cells which secrete part of the tear film

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
which conjunctiva is more vascular
palpebral
26
describe the movement the eyelid makes when shutting
sweeping action - lateral to medial this helps to wash debris towards the lacrimal sac
27
what is the iris covered by
cornea
28
what is the sclera covered by and what is it's function
conjunctiva - forms a defensive barrier to foreign bodies penetrating deep to the orbit
29
30
describe the lacrimal apparatus
lacrimal gland produces lacrimal fluid (parasympathetic CNVII) - this washes medially over eye toward medial angle - drains through **lacimral puncta** (openings in **lacrimal** **papillae**) - goes through **canaliculi** to **lacrimal sac** - and then **nasolacrimal** **duct** to reach **inferior meatus** in nose
31
what is the parasympathetic innervation of the lacrimal gland
CNVII
32
33
what can corneal light reflections be used for clinically
clinically to track the symmetry of bilateral eye positions/movements
34
what forms the outer layer of the eye
sclera and cornea
35
what holds 2/3 of the eye's refractive (focusing) power
the cornea
36
describe the layers of the cornea
37
how is the transparency of the cornea maintained
the endothelium maintains transparency by pumping fluid out of the stroma
38
where is the cornea thickest
peripherally
39
what is the stroma of the cornea formed by
reguarly spaced collagen fibres
40
what are the outer and inner parts of the lens known as
cortex and nucleus
41
what forms the middle (uvea - vascular layer) of the eye
*the uveal tract structures are continuous with eachother and pigmented*
42
function of iris
controls pupil diameter
43
function of ciliary body
controls **iris**, **shape of lens** (ciliary muscle) and secretion of **aqueous humour** (ciliary epithelium)
44
function of choroid
* nutrition and gas exchange * supplies the outer retina
45
what forms the inner layer of the eye
retina - photosensitive layer
46
describe the chambers of the anterior segment of the eye
anterior chamber between cornea and iris contains **aqueous humour** posterior chamber between iris and suspensory ligaments contains **aqueous humour**
47
how much of the eye does the posterior segment occupy
2/3rds
48
what does the posterior segment of the eye contain
vitreous body/humour - clear gel
49
what is a common location for floaters in the eye
vitreous body in posterior segment
50
cataract
clouding of the lens
51
52
define limbus
border of cornea and sclera
53
describe the circulation of aqueous
54
how does the composition of aqueous fluid allow for optical clarity
low protein content
55
what angle is being referred to in 'open' and 'closed' glaucoma
the iridocorneal angle
56
what does raised intraocular pressure cause
ischaemia of the retina and glaucoma
57
what is in the cavernous system
cavernous sinus internal carotid artery CNIII, IV, V1, V2, VI
58
59
60
Kiesselbach's area
61
what type of artery is the central artery of the retina
end artery - insufficient anastomoses to maintain viability of the tissue supplied if arterial occlusion occurs
62
what are the central artery and vein of the retina contained in
optic nerve (CNII)
63
what is the ophthalmic artery a branch of
internal carotid artery
64
what supplies the outer layers of the retina
the choroid
65
66
where does the inferior ophthalmic vein drain into
superior ophthalmic vein - to cavernous sinus
67
where does the superior ophthalmic vein leave the eye
via the superior orbital fissure
68
which cranial nerves exit the cranial cavity via the superior orbital fissure
CNIII, IV, V1 and VI
69
danger triangle
infection from here can spread to brain via cavernous sinus eg from popping spot (unlikely though)
70
fundus
interior surface of the eye includes retina, fovea, macula and optic disc can be visualised with fundoscopy
71
optic disc
point of CNII formation - the only point of entry and exit for blood vessels and CNII axons
72
where is one's blind spot
optic disc - there are no photoreceptors 15 degrees temporally in the visual field
73
where is the greatest density of cones
macula
74
where is the fovea
centre of macula it is a small depression in the macula which provides the most acute vision
75
describe the layers of the retina
76
what is the optic nerve formed from
the axons of the ganglion cells
77
how does monocular blindness occur
complete interruption of flow of central artery (end artery) or vein
78
how does loss of an area of visual field occur
complete interruption of flow in a retinal artery branch/retinal vein
79
Right eye:
80
which optic nerves cross at the optic chiasma
nasal retina nerves
81
where is light from objects in the right visual field processed by
left primary visual cortex
82
where do the rectus muscles originate from and insert onto
originate from common tendinous ring insert onto sclera
83
name the extraocular muscles
84
where do the oblique muscles insert
onto sclera
85
what does the levator palpebrae superioris do
lift the upper eye lid
86
describe the somatic innervation of the EO muscles
87
which EO muscles dont have secondary movements
medial and lateral rectus
88
what is the primary position of the eye
gaze directed forward
89
which EO muscle passes through the trochlea
superior oblique (supplied by CNIV)
90
lateral rectus movement and clinical testing
can **only abduct** (CNVI) - bring line of gaze into that of sup and inf rectus
91
superior rectus movement and clinical testing
when in abduction, can only **elevate** | (CNIII)
92
inferior rectus movement and clinical testing
when in abduction, can only **depress** | (CNIII)
93
medial rectus movement and clinical testing
can only **adduct** the eyeball brings line of gaze into that of sup and inf oblique
94
inferior oblique movement and clinical testing
when in adduction, can only **elevate** | (CNIII)
95
superior oblique movement and clinical testing
when in adduction, can only **depress** | (CNIV)
96
which muscles produce the movement of pure elevation
superior rectus and inferior oblique - SR adduction and IO abduction cancel each other out
97
which muscles produce the movement of pure depression
superior oblique (abduction) and inferior rectus (adduction)
98
what is the strongest eye muscle
medial rectus - maybe due to the ammount of accomodation performed

RB Y2 Ophthamology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions