Brainscape's Knowledge GenomeTM

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


See full index

BMB Test 3 > B7.040 Eye, Orbit, and Cranial Fossa > Flashcards

B7.040 Eye, Orbit, and Cranial Fossa Flashcards

1
Q

sclera

A

dense connective tissue continuous with dura mater of optic nerve and brain
white of eye

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

iris

A

pigmented diaphragm which surround the pupil

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

cornea

A

clear extension of the sclera which covers both the iris and pupil
provides 2/3 of focusing power of the eye

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

bulbar conjunctiva

A

thin, moist mucous membrane covering sclera

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

papebral conjunctiva

A

mucous membrane on inner surface of eyelids

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

lacrimal apparatus

A

lacrimal gland keeps mucous membranes of the eye moist
lacrimal caruncle in medial angle accumulates tears
superior lacrimal punctum is just lateral to the caruncle and is the beginning of the lacrimal canaliculus where tears are carried to the lacrimal sac
tears end up in nasolacrimal duct and drain into nasal cavity

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

pathway of tears

A 
lacrimal gland
caruncle
punctum
canaliculus
sac
nasolacrimal duct
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why do you sniffle when you cry

A

tears usually dry up before entering the nasal cavity, but with excessive tears they do not and they cause sniffles

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

lacrimal gland

A

almond sized
in anterior/superior portion of orbit
produces 1 ml of tears each day
controlled by parasympathetic nerves from CN VII

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

eyelids

A

protect eye from drying and light

lined by thin skin on external surface and highly vascular palpebral conjunctiva on inner surface

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

tarsal plate

A

dense connective tissue plate that gives form to each eyelid

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

Meibomian glands

A

glands within the tarsal plates which secrete fatty lubricants which prevent the lids from sticking

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

orbital septum

A

normally keeps orbital fat within orbit

prevents herniation

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

what is a sty

A

acute purulent inflammation of the eyelid, generally caused by staph aureus

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

treatment of sty

A

resolves in days to weeks

warm washcloth helps melt lipids that cause blockage of sebaceous glands

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

internal sty

A

inflammation of a Meibomian gland just under conjunctival side of eyelid

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

external sty

A

arises from an eyelash follicle or lid-margin gland (sebaceous or apocrine)

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

chalazion

A

Meibomian gland lipogranuloma
lump on eyelid as a result of chronic blockage of a tarsal gland
same treatment as sty, may require lancing if warm compresses doesn’t work
usually not infected and not painful

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

conjunctivitis

A

can be called pinkeye

commonly caused by allergic reaction (non infectious) or infections which are usually viral, but sometimes bacterial

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

allergic conjunctivitis

A

typically itchy

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

viral conjunctivitis

A

associated with a cold

watery discharge, variable itch

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

bacterial conjunctivitis

A

marked grittiness/irritation and a stringy, opaque, grey or yellowing mucopurulent discharge that may cause the lids to stick together

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

conjunctivitis prophylaxis

A

newborns delivered vaginally get antibacterial agents to protect against venereal diseases

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

2 muscles which raise the upper eyelid

A 
levator palpebrae superioris
superior tarsal (Muller)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

levator palpebrae superioris

A

skeletal muscle under voluntary control innervated by CN III

main elevator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

superior tarsal

A

smooth muscle innervated by sympathetic fibers

if innervation is lost, can cause 2 mm droop (ptosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

horner’s

A
  1. ptosis (loss of superior tarsal innervation)
  2. miosis (loss of dilator muscle in pupil)
  3. anhidrosis (loss of sym input to sweat gland)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

muscle that closes the eyelid

A

orbicularis oculi

innervated by CN VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is an orbital blow out fracture

A

breakage of maxillary bone (inferior wall of orbit) with subsequent protrusion of orbital contents into maxillary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

clinical features of orbital blow out

A

inability to look up due to trapping of inferior rectus in the maxillary bone fracture
lowered globe level cause by prolapse of soft tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

superior orbital fissure

A

located at apex of orbit
between lesser and greater wings of sphenoid bone
transmits CN III, CN IV, ophthalmic CN V1, CN VI, and superior ophthalmic vein into orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

optic canal

A

transmits optic CN II and ophthalmic artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

rectus muscles

A

move orbit and pull eye deeper into socket

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

oblique muscles

A

cause torsion of the orbit and protrusion of the eye forward within the orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

graves disease eye findings

A

hyperthyroidism
eyes protrude slightly (proptosis)
exophthalmos - may be due to increased size of EOMs and edema within the orbit due to autoimmune reaction to thyrotropin (TSH) receptor antigen which is expressed in retroorbital tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

annual ring of Zinn

A

common tendinous ring which surrounds the optic canal and superior orbital fissure
4 rectus muscles arise from here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

origin of superior oblique

A

runs through a pulley, the trochlea, which is attached to the superior/medial margin of the frontal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

origin of inferior oblique

A

arises from the maxillary bone margin just lateral to the nasolacrimal duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

insertion of superior oblique

A

sclera of eye in the superior, posterior, and lateral portion

40
Q

insertion of inferior oblique

A

sclera of the eye in the inferior surface in the posterior, lateral quadrant

41
Q

strabismus

A

pathological misalignment of the visual axes that cause a loss of depth perception and binocular vision

42
Q

incidence of strabismus

A 
2-3% of general population
3 mil in US annually
more prevalent in Caucasian females
multifactorial inheritance
onset before age of 5
43
Q

cause of strabismus

A

variation in the insertions of EOMs into orbit

44
Q

esotropia

A

one or both eyes turn inward

“cross eyed”

45
Q

exotropia

A

one eye deviates outward

less common

46
Q

eye adductors

A

MR
SR
IR

47
Q

eye abductors

A

IO
SO
LR

48
Q

eye elevators

A

IO

SR

49
Q

eye depressors

A

SO

IR

50
Q

medial rotators (intorsion)

A

SR

SO

51
Q

lateral rotators (extorsion)

A

IR

IO

52
Q

H test important

A

when lateral: SR and IR do vertical movements

when medial: IO and SO do vertical movements

53
Q

oculomotor nerve lesion

A
  1. lateral strabismus (down and out due to unopposed LR and SO)
  2. ptosis (paralysis of levator palpebrae)
  3. dilation of pupil
  4. loss of lens accommodation
54
Q

causes of sudden CN III palsy

A

aneurysm within posterior communicating
cavernous sinus thrombosis
subarachnoid hemorrhage

55
Q

contraction of SO muscle

A

eye rotates outward, downward, and with intorsion

56
Q

lesion of CN IV

A

patient tilts head toward unaffected side bc side with lesion is extorted

57
Q

CN VI palsy

A

weakness or paralysis of LR
eye on affected side rotates inward, medially due to unopposed MR action
causes diplopia

58
Q

cause of CN VI palsy

A

conditions which increase ICP stretch the abducens nerve as brainstem is pushed into foramen magnum
most common CN palsy, found in diabetics

59
Q

anterior chamber

A

anterior to iris and pupil
filled with aqueous humor
drains in canal of Schlemm at junction of the iris which the cornea and sclera (anterior chamber angle) into the venous blood

60
Q

posterior chamber

A

posterior to iris and pupil, but in front of lens and ciliary process
contains ciliary body which produces aqueous humor which flows out of pupil into anterior chamber

61
Q

glaucoma

A

excessive pressure within the eye

second leading cause of blindness in the world (leading in AAs)

62
Q

closed angle glaucoma

A

10%

blockage of fluid drainage at the canal of schlemm

63
Q

glaucoma exam

A

blowing a jet of air into the cornea and measuring the deformity

64
Q

open angle glaucoma

A

90%

overproduction of aqueous humor

65
Q

muscles in the iris

A
  1. radial, dilator muscle

2. circular, sphincter muscle

66
Q

pupil dilator muscle

A

myoepithelial cells innervated by ganglionic sympathetics from superior cervical ganglia
a1 receptors
respond to NE

67
Q

cocaine

A

inhibits reuptake of NE, dilating eye

68
Q

pupil sphincter muscle

A

smooth muscle innervated by postganglionic parasympathetic fibers from ciliary ganglia via short ciliary nerves
muscarinic ACh receptors

69
Q

anticholinergics

A

atropine and tropicamide

cause pupil dilation as dilator muscle is unopposed

70
Q

accommodation

A

lens changes shape to focus on near objects

71
Q

distance vision

A

ciliary muscle is relaxes, ligaments pull on and flatten the lens

72
Q

near vision

A

ciliary muscle contracts, releases tension on the ligaments and the lens becomes more rounded

73
Q

presbyopia

A

lens elasticity lost with age
common
many older individuals have difficult reading without the aid of reading glasses (far sighted)
lens does not round up as much as it used to

74
Q

cataract

A

clouding of the lens
common (half of people in US have them by 80)
develop slowly and can affect one or both eyes, typically in those over 50

75
Q

risk factors for cataracts

A

diabetes, smoking, prolonged sun exposure, alcohol, genetics

76
Q

exposure of central vein and artery to CSF pressure

A

course inside the optic nerve

CSF pressure is transmitted into the orbit

77
Q

papilledema

A

excessive CSF pressure as determined via exam of fundus

causes optic disc to swell and blood, especially venous blood to pool in the veins on the surface of the retina

78
Q

fundus during hypertension

A

arteries become swollen and tend to restrict venous return

venous nicking

79
Q

cavernous sinuses

A

dural sinuses 2 cm long and 1 cm wide located on each side of the sella turcica and body of sphenoid bone
connected by intercavernous sinuses and receive blood from superior and inferior ophthalmic veins, superficial middle cerebral, and sphenoparietal sinus
rained by superior and inferior petrosal sinuses

80
Q

carotid-cavernous sinus fistula

A

rare
if an aneurysm in the internal carotid artery ruptures into the cavernous sinus, then the affected eye/orbit may fill with blood and pulsate
blood suddenly appears in sclera and orbital tissue as superior and inferior ophthalmic veins become pressurized close to arterial pressures

81
Q

AVMs

A

arterial venous malformations
cerebral arteries and veins form abnormal tangles or webs
can be clinically silent or bleed and cause infarction in nearby parts of the brain

82
Q

symptoms of carotid-cavernous sinus fistula

A 
pulsating exophthalmos (forward protrusion of the eye) 
extraocular palsies (CN III, IV, and VI run through cavernous sinus)
83
Q

treatment of carotid-cavernous sinus fistula

A

insertion of a balloon or coil into shunt via a catheter or surgery

84
Q

corneal reflex

A

mediated by sensory fibers of CN V1 and motor fibers of CN VII
bilateral blink response when edge of cornea is touched

85
Q

example of cause of dysfunction of corneal reflex

A

VIII tumors (acoustic neuromas) can compress CN VII in acoustic meatus

86
Q

contents of anterior cranial fossa

A

frontal lobes of the cerebral hemispheres
orbital plates of frontal bones
crista galli and cribriform
plate of the ethmoid bone; the falx cerebri
sphenoid ridge
clinoid processes

87
Q

falx cerebri

A

attaches to frontal crest and crista galli

88
Q

sphenoid ridge

A

formed by lesser wing of the sphenoid

89
Q

clinoid processes

A

site of attachment for tentorium cerebelli

90
Q

contents of middle cranial fossa

A 
temporal lobes
dorsum sellae
posterior clinoid processes
petrous
squamous
91
Q

dorsum sellae

A

behind sella turcica of sphenoid bone

92
Q

posterior clinoid processes

A

of sphenoid bone

93
Q

petrous

A

portion of temporal bones

94
Q

squamous

A

portion of temporal bones

95
Q

posterior cranial fossa

A

occipital lobes lying on tentorium cerebelli, cerebellum, pons, and medulla
occipital bone
tentorium cerebelli

BMB Test 3 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions