Brainscape's Knowledge GenomeTM

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


See full index

OPTHT801 > Orbital vasculature > Flashcards

Orbital vasculature Flashcards

1
Q

What is the origin of the ophthalmic artery?

A

C6 segment of ICA
Within cavernous sinus
Can also arise from C4 or C5 segment. Can also arise from MMA, ACA, ICA bifurcation and basilar artery.

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

What is the course of the ophthalmic artery?

A

Initially lies within dural arachnoid sheath of optic nerve
Then pierces sheath on exiting optic canal, runs inferolaterally along optic nerve, then crosses superomedially (inferomedially in 15% of pop) along optic nerve accompanied by nasociliary nerve

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

Which muscles does the ophthalmic artery lie between?

A

Superior oblique and medial rectus

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

What are the terminal branches of the ophthalmic artery?

A

Supratrochlear artery and dorsal nasal artery

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

What are the branches of the ophthalmic artery?

A 
Central retinal artery
Muscular branches (sup + inf)
Posterior ciliary arteries
Lacrimal artery
Supraorbital artery
Posterior ethmoidal artery
Anterior ethmoidal artery
Medial palpebral arteries

Supratrochlear artery} Terminal branches
Dorsal nasal artery}

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

How do ophthalmic artery aneurysms present?

A

Subarachnoid haemorrhage and visual defecits

Incidental diagnosis 35%

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

Describe the course of the central retinal artery

A

First branch of ophthalmic artery
Starts about 1.25cm behind the eyeball
Pierces dural sheath and passes across subarachnoid space to enter the centre of the optic nerve
Runs with retinal vein and pierces lamina cribosa to enter eyeball

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

What is a key anatomical variant which improves outcomes in central retinal artery occlusion?

A

Presence of cilioretinal artery

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

Describe the lacrimal artery

A 
2nd branch of ophthalmic artery
Runs above lateral rectus
Accompanied by lacrimal nerve
Supplies lacrimal gland and eyelids
Gives rise to lateral palpebral arteries( anastomose and form superior and inferior palpebral arches and anastomses with external carotid artery vis transverse facial artery) and zygomaticofacial and zgyomaticotemporal arteries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where do the anterior ciliary arteries originate?

A

Muscular branch arteries to rectus muscles

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

What is the origin of the long and short ciliary arteries?

A

Posterior ciliary arteries from ophthalmic arteries

Forms major arterial circle of the iris

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

Describe the course of the supraorbital artery

A

Arises from ophthalmic artery as it crosses optic nerve
Passes superiorly around superior rectus and LPS
Exits orbit via supraorbital notch
Supplies LPS, frontal sinus, upper eyelid, skin of scalp and forehead
gives off posterior and anterior ethmoidal arteries

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

Where do the medial palpebral arteries arise from?

A

Inferior part of ophthalmic artery below the SO pulley

Travel behind lacrimal sac and form palpebral arches which supply eyelids and conjunctiva

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

Describe the course of the dorsal nasal artery

A

One of the terminal branches of the ophthalmic artery

Descends down the side of the nose, gives branches to the lacrimal sac and anastomses to the facial artery

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

Describe the course of the supratrochlear artery

A

Leaves orbit via orbital septum above SO pullery accompanied by supratrochlear nerve
Supplies skin of forehead and skull

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

What is the drainage of the orbit?

A

Superior ophthalmic vein
Vortex veins
Drains into cavernous sinus
Communicates with arterial system posteriorly to the orbit, and anteriorly around rim of optic cup

17
Q

How does the ophthalmic artery develop?

A

First portion arises from hyaloid artery

Second portion arises from stapedial artery

18
Q

Which other artery (besides ophthalmic) may be the main orbital artery in some cases?

A

Middle meningeal artery

19
Q

What are the 3 portions of the ophthalmic artery

A

Intracranial (internal carotid artery)
Intracanalicular (optic canal)
Intraorbital (annulus of zinn to intraconal space)

20
Q

Does the orbital portion of the ophthalmic artery run over or under the optic nerve?

A

Medially over (81%) or under (19%)

21
Q

Where does the recurrent meningeal artery run?

A

Passes through superior orbital fissure

22
Q

What does the superior muscular artery supply?

A

SR LR LPS and SO

23
Q

What does the inferior muscular artery supply?

A

IR, MR and IO

24
Q

Which ethmoidal artery is bigger?

A

Anterior ethmoidal artery Passes through anterior ethmoidal canal to reach anterior cranial fossa

25
Q

Describe the course of the infraorbital artery

A

Arises from maxillary artery (external carotid) in the pterygopalatine fossa and enters orbit via inferior orbital fissure
Supplies inferior orbit, branches to IR and IO, lacrimal sac and gland and soft tissues of orbital floor

26
Q

What is the clinical relevance of angular vein?

A

Descends across anterior limb of medial canthal tendon so is at risk during DCR
Continuous with facial vein

27
Q

What is the clinical relevance of the facial vein

A

Vein has no valves

Communicates with pterygoid venous plexus and cavernous sinus so sepsis may spread from face to meninges

28
Q

Where does the superior ophthalmic vein run?

A

Accompanies ophthalmic artery between the optic nerve and SR through superior orbital fissure to cavernous sinus
Drains inferior ophthalmic and middle ophthalmic veins plus 2 vortex veins, muscular, ethmoidal and palpebral veins

29
Q

What is the difference between the middle ophthalmic vein and medial ophthalmic vein?

A

Middle: present in 1-20% of orbits.Runs with inferior ophthalmic vein
Medial: present in 40% of orbits

30
Q

What are the key features of the cavernous sinus

A

3cm long, 1cm high 0.5cm wide
Contains ICA, abducens nerve and sympathetic plexus
Transversed by 3rd 4th and 5th cranial nerves in the lateral wall
Drained by the superior and inferior sinuses and emissary veins

31
Q

What is the lymph drainge of the eyelids?

A

lat 2/3 upper eyelid, lat 1/3 lower eyelid and lat 1/2 conjunctiva =preauricular

med 1/3 upper eyelid,med 2/3 lower eyelid and med 1/2 conjunctiva = submandibular nodes

32
Q

What is the lymphatics of the orbit?

A

Absent

Excess fluid appears to pass posteriorly

33
Q

Where does the inferior ophthalmic vein run?

A

Arises anteriorly on the floor of the orbit from inferior venous network within the muscle cone. Runs backwards on inferior rectus and drains into cavernous sinus. Receives inferior 2 vortex veins

34
Q

What do the superior and inferior roots of the superior ophthalmic vein connect to?

A

superior root: supraorbital vein

inferior root: angular vein

OPTHT801 (20 decks)

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