Brainscape's Knowledge GenomeTM

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


See full index

Head and Neck Anatomy > The eye and the orbit > Flashcards

The eye and the orbit Flashcards

1
Q

what bones make up the orbit?

A 
frontal 
zygomatic 
maxillary 
lacrimal 
ethmoid 
sphenoid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what do vessels and nerves which supply the orbit enter?

A

through foramina;
optic foramen
superior orbital fissure
inferior orbital fissure

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

which structures pass through the optic foramen?

A

optic nerve

ophthalmic artery

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

which structures pass through the superior orbital fissure?

A 
ophthalmic vein
ophthalmic nerve (V1)
occulomotor nerve (III)
trochlear nerve (IV)
abducent nerve (VI)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

which structures pass through the inferior orbital fissure?

A

maxillary nerve (V2)

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

what is the depth of the eyeball and the orbit?

A 
eyeball = 24mm
orbit = 40mm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

apart from the eye, what mainly fills the orbit and why is this of clinical significance?

A

fat tissue
it is one of the last reserves of fat that we lose if we go into starvation
thats why if someone has sunken in eyeballs it means they have lost a lot of body fat

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

what muscles control the eyelids and what are their functions?

A

orbicularis oculi - depresses/closes the eyelid

levator palpebrae superioris - elevates/ opens the eyelid

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

what is the nerve supply of the levator palpebrae superioris?

A

CN III - Occulomotor nerve

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

what helps the orbit eep its shape?

A

hard palate (tarsal palate)

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

what is found within the tarsal/hard palate of the orbit and what is its function?

A

meibomian glands

helps prevent evaporation of the eyes tear film

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

what type of glands are found are the eyelashes?

A

sebaceous glands

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

describe the covering of the conjunctiva.

A

covers the inside of the eyelids and loops back over the sclera
continues to the fornix (conjunctival fornices)
stops at the corneosclera junction

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

what part of the eye does the cornea and sclera cover?

A

cornea covers the anterior 1/6

sclera covers the posterior 5/6

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

what is the functions of the iris, ciliary body and choroid?

A

iris controls diameter of the pupil and thus the amount of light that enters
the ciliary body suspends the lens and produces aqueous humour
the choroid supplies blood to the outer layers of the retina

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

what is the function of the aqueous and venturous humour?

A

aqueous helps control intraocular pressure

venturous humour cushions the retina

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

what are the different chambers of the anterior segment of the eye?

A

anterior chamber infant of the iris

posterior chamber behind the iris

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

describe the drainage of the aqueous humour.

A

produced from ciliary body and secreted into posterior chamber
comes through the pupil until it reaches a corner - the angle of the anterior chamber
enters trabecular meshwork at this corneosclero junction
enters the schemms canal this drains into veins in the sclera - episclero veins

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

wha are the functions of the intrinsic and extrinsic muscles of the eye?

A

intrinsic controls pupil diameter and helps alter lens curvature to enable us to see near objects
extrinsic muscles move the eye

20
Q

what are the intrinsic muscles and their nerve supply?

A

cilliaris muscle - occulomotor nerve III
constrictor pupillae - occulomotor nerve III
dilator pupillae - sympathetic plexus

21
Q

which muscle helps the us to see near objects and how?

A

cilliaris muscle

alters lens curvature

22
Q

what are the extrinsic muscles and their nerve supply?

A 
superior, inferior, medial and lateral rectus 
superior and inferior oblique 
superior orbital = trochlear nerve IV
superior rectal = abducent nerve VI
everything else = Occulomotor nerve III
23
Q

which muscle originates from the lesser wing of the sphenoid (roof of orbit posteriorly) ?

A

superior oblique

24
Q

which muscle originates in the medical part of the orbit floor (anteriorly) ?

A

inferior oblique

25
Q

where do the extrinsic muscles attach to the sclera?

A

rectus muscles anteriorly

oblique muscles posteriorly

26
Q

what is the nerve innervation of the lacrimal gland?

A

parasympathetic facial nerve VII

27
Q

regarding the lacrimal gland, what happens when we close our eye lids?

A

constriction of the orbiculares oculists muscle creates a negative pressure opening up the lacrimal sac so the fluid is sucked into the punctae for drainage into the lacrimal duct

28
Q

where is the lacrimal gland situated?

A

anteriolaterally of the orbit

29
Q

before tears enter the lacrimal sac, what is it sucked through?

A

punctae found on the medial side of each eyelid

30
Q

what supplies motor and sensory innervation to the orbit?

A

motor ;

  • optic (CN II)
  • occulomotor (III)
  • trochlear (IV)
  • abducent (VI)

sensory - ophthalmic V1 and maxillary V2 branches of the trigeminal

31
Q

what foramen does the sensory innervation of the orbit pass through?

A

opthalmic nerve V1 - superior orbital fissure

maxillary nerve V2 - inferior orbital fissure

32
Q

what are the main branches of the ophthalmic nerve?

A

nasociliary branch
lacrimal branch
frontal branch

33
Q

what does the maxillary branch V2 supply?

A

sensory innervation to the lower part / floor of the orbit and eyelids

34
Q

arterial supply is via what main artery?

A

opthalmic artery which is a main branch of the internal carotid

35
Q

the opthalmic artery goes through the orbital cavity via what foramen?

A

optic foramen

36
Q

what branches does the ophthalmic artery give off?

A

central retinal artery

short and long posterior ciliary arteries

37
Q

which arteries supply the choroid and which parts?

A

short posterior ciliary artery supplies the posterior part of choroid
long posterior ciliary arteries supply anterior choroid, iris and ciliary body

38
Q

what is the blood supply of the retina?

A

the outer layer supplied by the choroid (which is supplied by the short and long posterior ciliary arteries)
the inner layer supplied by the central retinal artery

39
Q

what does the central retinal artery travel within?

A

the substance of the optic nerve

40
Q

how can you view the blood supply of the eye?

A

through an ophthalmoscope (fund picture)

41
Q

what is the bright small circle found in the fund picture?

A

optic disc

42
Q

what do you find at the optic disc?

A

the start of the optic nerve

in the centre you find the central retinal artery and vein

43
Q

what is the name of the venous sinus which drainage of the orbit leads to?

A

cavernous sinus

44
Q

where are the venous sinuses situated?

A

between the layers of the dura matter

45
Q

what is the epithelium lining of the venous sinus?

A

squamous epithelium (endothelium)

46
Q

where do you find the cavernous sinus?

A

situated on either side of the body of the sphenoid bone where the pituitary fossa is

47
Q

what structures lie within/near the cavernous sinus?

A

within the sinus = internal carotid artery
lying superior = optic nerve
lying within the walls of the dura matter are the nerves which enter the orbit through the superior orbital fissure - III, IV, VI, opthalmic and optic nerves

Head and Neck Anatomy (13 decks)

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