Exam 1 - 004 Overview of Ocular Circulation Flashcards

(38 cards)

1
Q

Pathway of the Ophthalmic Artery

A

 Branches from the internal carotid artery
 Enters the orbit through the optic canal
• Inferior and lateral to the optic nerve
• Lies within the muscle cone formed by the four rectus muscles that arise from the common tendinous ring
 In the orbit it runs forward a short distance between the optic nerve and lateral rectus
 Turns medial
 Crosses above the optic nerve
 Proceeds to the medial wall with the nasociliary nerve
 Travels forward along the medial wall with the nasociliary nerve, giving off branches as it goes

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

Branches of the Ophthalmic Artery

A
	Central Retinal A*
	Lacrimal A
	Muscular branches
	Posterior Ciliary arteries
•	Long posterior Ciliary A. (LPCA)*
•	Short Posterior Ciliary A (SPCA)*
	Supraorbital A
	Supratrochlear A
	Anterior Ethmoidal A
	Posterior Ethmoidal A
	Medial Palpebral A
	Dorsal Nasal A
	Meningeal A
•	Variable
•	Runs posteriorly through SOF to anastomose with the middle meningeal artery in the middle cranial fossa
*supplies the eyeball, along with anterior ciliary arteries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the direct origin of the medial and lateral palpebral arteries?

A

Lacrimal artery

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

What is the pathway of the lacrimal artery?

A

 Lacrimal A. Runs forward on the upper border of the lateral rectus (with the lacrimal nerve
• While in the orbit it supplies the lacrimal gland
 Pierces the orbital septum
 Terminates as the lateral palpebral arteries (2)
• Supplies that skin and conjunctiva of the lateral half of the upper and lower eyelids

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

Origin of SPCA

A

 Medial and lateral posterior ciliary arteries

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

Origin of LPCA

A

 Posterior Ciliary Arteries

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

Pathway of the central retinal artery

A

• Branches from the ophthalmic artery after it enters the orbit
• Runs under the optic nerve
• Eventually pierces the optic nerve about 10-12 mm posterior to the eyeball
o Passes through the center of the optic nerve

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

Structures supplied by the central retinal artery

A
  • The central part of the optic nerve from its point of entry into the optic nerve to the posterior border of the lamina cribrosa
  • INNER layers of the retina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Path of the short posterior ciliary arteries

A

 Arise from the medial and lateral Posterior Ciliary Arteries (about 7-10 of them)
 Pierce the back of the eyeball in a ring around the optic nerve
 Run forward in the space between the sclera and the choroid
• The space is called suprachoroidal space

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

Structures supplied by the SPCA

A

 Sclera near where they enter the eyeball
 Some supply the posterior portion of the choroid up to the equator
 Others anastomose in the sclera to supply the laminar part of the optic nerve
• As the circle of Zinn-Haller

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

Pathway of the LPCA

A

 Branch from the Posterior Ciliary Arteries (one medial and one lateral)
 Pierce the sclera at the back of the eyeball
 Run forward in the suprachoroidal space to the ciliary body
• Divides into superior and inferior branches at the ciliary body
• Superior and inferior branches anastomose with each other and the anterior ciliary arteries
o forms the major arterial circle of the iris (a discontinuous arterial ring which is in the CILIARY BODY)
 LPCA gives off 3-5 recurrent branches at the ora serrata
• Pass directly back to the choroid anterior of the equator

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

Structures supplied by LPCA

A

 Sclera where they enter the eyeball
 Iris at the major arterial circle of the iris
 Ciliary body the major arterial circle of the iris
 Choroid anterior to the equator of the eyeball (supplied by the recurrent branches)

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

Pathway of the anterior ciliary arteries and their recurrent branches

A

 Originate from the muscular arteries that supply the four rectus muscles
• 2 for SR, MR and IR
• 1 for LR
 After supplying the muscles, the 7 muscular arteries continue anteriorly as the anterior ciliary arteries
• ACA pass forward
• Bifurcates just beyond the rectus muscle insertions
o Some branches continue forward beneath the bulbar conjunctiva (episcleral arteries)
o Some branches pierce the sclera (major perforating branches)
 Gives off 8-12 recurrent branches that pass backwards to supply the choroid anterior to the equator of the eyeball
 After giving off the branches, MPB joins the LPCA in the ciliary body to form the major arterial circle of the iris (MAC)

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

Structures supplied by the anterior ciliary arteries and their recurrent branches

A

 Sclera (major perforating branches)
 Choroid anterior to the equator of the eyeball (recurrent branches)
 Iris (MAC)
 Ciliary Body (MAC)

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

What is the major arterial circle of the iris (MAC)?

A

o It is the anastomosis of the superior and inferior branches of the LPCA with the anterior ciliary arteries

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

What makes up the MAC

A

o 2 LPCA
 Superior and inferior branches
o 7 anterior ciliary arteries

17
Q

What supplies the choroid?

A
	Anterior to the equator
•	2 LPCA
•	7 anterior ciliary arteries
	Posterior to the equator
•	15-20 short posterior ciliary arteries
18
Q

What supplies the central part of the optic nerve behind lamina cribrosa?

A

 Central Retinal Artery

19
Q

What supplies the lamina cribrosa of the optic nerve

A

 15-20 short posterior ciliary arteries

20
Q

What supplies the central retinal layers

A

 Central Retinal Artery

21
Q

What supplies the iris?

A

 2 LPCA

 7 anterior ciliary arteries

22
Q

What supplies the ciliary body?

A

 2 LPCA

 7 anterior ciliary arteries

23
Q

What supplies the sclera?

A

 15-20 short posterior ciliary arteries
 2 LPCA
 7 anterior ciliary arteries

24
Q

Central Retinal Vein

A

 Formed from tributaries corresponding roughly to the branches of the central retinal artery
 Leaves the eye by passing through the optic nerve with the central retinal artery through the SOF

25
What does the central retinal vein receive blood from and drain into?
```  Receives blood from • Capillaries supplying the inner layers of the retina  Drains into • Cavernous sinus OR • Superior ophthalmic vein ```
26
Superior Ophthalmic vein
``` larger than the inferior ophthalmic vein  Receives blood from • Don’t need to know but: o Muscular branches (from SO, SR, MR and levator palpebrae superioris) o Lacrimal vein o Ethmoidal veins • Supraorbital vein • Supratrochlear vein • Angular vein • Central retinal vein (in some cases • Superior vortex veins (which receive blood from the choroid)  Drains into • Cavernous sinus  Passes through the SOF above the common tendinous ring ```
27
Inferior Ophthalmic Vein
 Arises from a venous plexus on the anterior floor of the orbital cavity • SAYS WE DON’T NEED TO KNOW THIS  Passes posteriorly on the inferior rectus muscle  Pathway • Passes through SOF below the common tendinous ring to drain into the cavernous sinus • Passes through the IOF to drain into the pterygoid venus plexus
28
What does the inferior ophthalmic vein receive blood from and drain into?
```  Receives blood from • Angular vein • Inferior vortex vein • Don’t need to know these: o Muscular branches (from IR, IO and LR) o Inferior conjunctiva and lacrimal sac  Drains into • Cavernous sinus • Pterygoid venous plexus ```
29
Vortex Veins
```  Usually four, one for each quadrant of the eye • Can vary from 3 to 6  Receives blood from (drains) • Areas supplied by the LPCA and SPCA including the choroid and portions of the ciliary body and iris  Drains into • Superior side o Superior ophthalmic vein • Inferior side o Inferior ophthalmic vein ```
30
Infraorbital Veins
```  Receives blood from • Facial vein  Drains into • Pterygoid venous plexus  Passes posteriorly through the infraorbital foramen, infraorbital canal and infraorbital groove. Then exits the orbit through the IOF ```
31
Vortex Vein Ampulla
o Located at the equator of the eyeball o The dilated beginning of the vortex vein  Site where the choroidal veins drain  Together, the choroidal veins and the ampula look like an octopus – the choroidal veins are tentacles and the ampula the body o Exits the eyeball about 6 mm posterior to the equator of the eyeball o Readily visible during a DFE with a BIO
32
Supraorbital Artery Pathway
 In the orbit it passes forward above the levator palpebrae superioris • Travels with the supraorbital nerve  Exits the orbit through the supraorbital foramen  Anastomosis with superficial temporal and supratrochlear arteries on the scalp
33
Structures supplied by the supraorbital artery
 Levator palpebrae superioris  Superior rectus  Superior oblique  Skin and muscles of the forehead and scalp
34
Ethmoidal arteries
``` o Anterior Ethmoidal A  Supplies • Anterior, middle and posterior ethmoidal air cells • Frontal sinus • Nasal cavity • Skin of the nose o Posterior Ethmoidal A  Supplies • Posterior ethmoidal air cells • Sphenoid sinus ```
35
Supratrochlear Artery
o One of the terminal branches of the ophthalmic artery o Pathway  Leaves the orbit on the medial side by piercing the orbital septum above the puller for the superior oblique • Travels with the supratrochlear nerve  Anastomosis with superficial temporal and supraorbital arteries in the scalp o Supplies  Skin of the forehead and scalp  Muscles of the forehead
36
Medial Palpebral arteries
o Two arteries o Pathway  Arise from the anterior portion of the ophthalmic artery just below the pulley for the superior oblique  Pierce the orbital septum  Anastomosis with lateral palpebral arteries o Supplies  Medial half of the upper and lower eyelids and conjunctiva
37
Nasal Artery
o One of the terminal branches of the ophthalmic artery o Pathway  Leaves the orbit on the medial side by piercing the orbital septum below the pulley for the superior oblique  Sends branches to the lacrimal sac  Runs along the side of the nose to anastomose with the angular artery
38
Infraorbital Artery
o Pathway  Branches from the maxillary artery  Enters the orbit through the IOF  Passes forward through the infraorbital groove, infraorbital canal and infraorbital foramen  Exits the orbit by passing through the infraorbital foramen  Gives off the anterior superior alveolar artery to supply the maxillary sinus and upper teeth o Supplies  Inferior rectus muscle  Inferior oblique muscle  Lacrimal sac