Orbital Vasculature Part I Flashcards
(130 cards)
1
Q
What kind of BV carry oxygenated blood away from the heart
A
Arteries
2
Q
What blood vessels are under higher pressure?
A
Arteries
3
Q
What are the layers of the arteries
A
- external tunic (adventitia)
- tunica media
- tunica intima
- internal elastic lamina
- external elastic lamina
4
Q
External tunic (adventitia) of arteries
A
Collage fibers/connective tissue
5
Q
Tunica media of arteries
A
Composed of smooth muscle and elastic tissue
6
Q
Tunica intima of arteries
A
Composed of endothelial cells (direct contact with lumen)
7
Q
Internal elastic lamina of arteries
A
Outer most portion of the tunica intima
8
Q
External elastic lamina of arteries
A
Inner most portion of the tunica adventitia
9
Q
Where do arteries drain to
A
Arterioles
10
Q
Primary site of vascular resistance
A
Arterioles
11
Q
Where do arterioles drain to
A
Capillaries
12
Q
What is the tunica media of arterioles like compared to the arteries
A
Thinner
13
Q
Endothelial cells and their basement membrane
A
Capillaries
14
Q
What lines the external surface of the capillaries?
A
Pericytes
15
Q
What is the function of the capillaries
A
exchange of nutrients and metabolic waste
16
Q
What are venules lined with
A
Endothelial lining Tunica media (thin) Tunica adventitia
17
Q
Where do venules drain to
A
Veins
18
Q
Carry deoxygenated blood to heart
A
Veins
19
Q
Tunica of veins
A
Same as arteries, but tunica media is much thinner and the tunica adventitia is much thicker. They lack elastic lamina
20
Q
What does the brachiocephalic artery give rise to
A
The right subclavian and tight common carotid artery
21
Q
Where do the left common carotid artery and the left subclavian artery branch from?
A
Directly from the Arch of the aorta
22
Q
When does the common carotid artery bifurcate and what does it bifurcate into?
A
After it enters the carotid sheath, it bifurcate into the internal and external carotid artery
23
Q
As the internal carotid artery ascends into the neck inside the carotid sheath, what does it carry with it?
A
A plexus of postganglionic sympathetic nerve fibers
24
Q
Does the internal carotid artery have any branches outside of the skull?
A
No
25
How does the internal carotid artery enter the skull
Through the carotid canal
26
Where does the internal carotid artery emerge from and into what fossa?
Emerges from the petrous portion of the temporal bone and into the middle cranial fossa
27
How does the internal carotid course?
Anterior over the foramen lacerum
28
What sinus does the internal carotid artery enter after it courses over the foramen lacerum?
Cavernous sinus
29
The ________ nerve sits inferolateral to the internal carotid artery within the cavernous sinus
Abducens (CN VI)
30
What cranial nerves sit lateral to the internal carotid artery and course in the lateral wall of the cavernous sinus?
- oculomotor nerve (CNIII)
- trochlear nerve (CNIV)
- ophthalmic and maxillary divisions of the trigeminal nerve (CNV)
31
Where does the carotid artery exit the roof of the cavernous sinus?
Just medial to the anterior clinic process
32
As the internal carotid artery dips inferior to the optic nerve, what happens?
It gives off the ophthalmic artery at the posterior opening of the optic canal
33
Where does the ophthalmic artery enter the optic canal?
Inferior and lateral to optic nerve
34
How does the ophthalmic artery course in the dural sheath of optic nerve?
Anterior, and then pierces dural sheath and lies just lateral to the optic nerve in the orbit
35
Once the ophthalmic artery pireces the dural sheath of the optic nerve, what does it do?
Courses anterior for a shirt distance stalling lateral to the optic nerve, then makes an abrupt medial turn over the optic nerve and is joined by the nasociliary nerve
36
As the ophthalmic artery joins the nasociliary nerve, how does it run?
Courses anterior along the medial wall of orbit between the superior oblique muscle and medial rectus muscle
37
How does the ophthalmic artery terminate
As the supratrochlear and dorsonasal arteries
38
How many arteries branch from the ophthalmic artery?
Eleven branches to supply eye, orbit, and extra orbital structures
Ocular (2)
Orbital (2)
Extraorbital (7) and one sorta
39
What are all the branches of the ophthalmic artery?
- central retinal artery
- ciliary arteries
- Lacrimal artery
- muscular arteries
- supraorbital artery
- posterior ethmoidal artery
- anterior ethmoidal artery
- recurrent meningeal artery
- medial palpebral arteries
- supratrochlear artery
- dorsonasal artery
40
What are the ocular branches of the ophthalmic artery
- central retinal artery
| - ciliary arteries
41
What are the orbital branches of the ophthalmic artery?
- lacrimal artery
| - muscular arteries
42
What are the extra orbital branches of the ophthalmic artery?
- supraorbital
- posterior ethmoidal
- anterior ethmoidal
- recurrent meningeal
- medial palpebral
- supratrochlear
- dorsonasal
43
What is the first and smallest branch of hte ophthalmic artery?
Central retinal artery
44
Where does the central retinal artery branch off of the ophthalmic artery?
Near optic canal and inferior to optic nerve
45
How does the central retinal artery course after it comes off of the ophthalmic artery?
Anterior and pierces the dural sheath of optic nerve 5-15mm from posterior scleral aperture
46
After the central retinal artery pierces the dural sheath of the optic nerve, what does it do?
Obliquely crosses subarachnoid space to enter substance of the nerve and course with the central retinal vein to the lamina cribrosa and enters back of the eye
47
What supplies the pill meninges surrounding the optic nerve?
Small pial branches from the central retinal artery
48
Where does the central retinal artery emerge inside the ey
On nasal side of optic disc just nasal to the central retinal vein
49
Once the central retinal artery enters the eye, how does it branch?
Divides into superior and inferior branches, which bifurcate into temporal and nasal branches
50
What does each branch of the central retinal artery do once it is in the eye?
Provides arterial blood to the inner retinal layers in each respective quadrant
51
Where does the ciliary artery branch from the ophthalmic artery?
As it courses over optic nerve, they arise as medial and lateral trunks that give rise to short and long posterior ciliary arteries
52
Long posterior ciliary arteries
- medial and lateral
- pierce sclera medial and lateral to arterial circle of Zinn-Haller
- travel anterior inside the eye via suprachoroid (perichoroid) space
53
What does the long posterior ciliary arteries supply blood to
Urea anterior to equator
54
Short posterior ciliary arteries
- 10-20 branches
| - pierce sclera and form anastomotic loop around optic nerve known as arterial circle of Zinn (Haller)
55
What does the short postioer ciliary arteries supply
Blood to urea posterior to equator
56
What can the short posterior ciliary arteries give rise to
May give rise to cilioretinal artery
57
Where does the lacrimal artery branch off of the ophthalmic artery?
Near optic canal
58
How does the lacrimal artery course?
On superior border of lateral rectus, superior and inferior lateral palpebral arteries, and zygomatic artery, which branches into zygomaticotemporal and zygomaticotemporal arteries
59
What does the lacrimal branch of the ophthalmic artery anastomose with
Branches of superficial temporal artery (external carotid artery)
60
How does the muscular artery branch from the ophthalmic artery
As medial and lateral trunks
61
What does the medial muscular artery supply?
Inferior rectus, inferior oblique, and medial rectus
62
What does the lateral trunk of the muscular artery supply
SUPERIOR RECTUS, SUPERIOR OBLIQUE, LEVATOR PALPEBRAE SUPERIORIS
63
What do the muscular arteries to the rectus muscles branch into?
Anterior ciliary arteries
64
Each muscular artery branches into two anterior ciliary arteries, except the muscular artery to the _______
Lateral rectus, this one branches into only one artery.
65
How many solitary arteries are there in total?
7 (all muscular arteries have to branches of these except the lateral rectus which only has one)
66
Anterior ciliary muscles
Either perforate sclera at tendinous insertions of rectus muscles and join long posterior ciliary arteries to form major arterial circle of iris, or stat superficial and give rise to anterior conjunctival arteries
67
Where does the supraorbital artery branch off of the ophthalmic artery?
After the ophthalmic artery crosses the optic nerve
68
How does the supraorbital artery course?
Courses with frontal nerve between periorbita and levator palpebrae superioris muscle
69
Where does the supraorbital artery exit the orbit?
Supraorbital foramen (notch)
70
What does the supraorbital artery anastomose with?
Supratrochlear artery and superficial temporal artery (external carotid)
71
What supplies blood to levator palpebrae superioris, superior rectus, superior oblique, scalp, and upper eyelid?
Supraorbital artery
72
How does the postioer ethmoidal artery course?
Along the medial wall between the superior oblique and medial rectus
73
What foramen does the postioer ethmoidal artery enter and with what nerve?
Enters the postioer ethmoidal canal with the posterior ethmoidal nerve
74
What gives blood supply to the posterior ethmoidal and sphenoid air sinuses?
Posterior ethmoidal artery
75
Which is the larger of the two ethmoidal arteries?
Anterior ethmoidal artery
76
What Forman does the anterior ethmoidal artery enter and with what nerve?
Anterior ethmoidal canal with the anterior ethmoidal nerve
77
What supplies the anterior and middle ethmoidal air sinuses and the sphenoid sinuses?
Anterior ethmoidal artery
78
What passes through the cribiform plate of the ethmoid bone to supply the nasal cavity and skin of the nose?
Anterior ethmoidal artery
79
How does the recurrent meningeal artery course?
Posterior through superior orbital fissure to supply meninges in middle cranial fossa
80
Medial palpebral arteries
- branch of ophthalmic
- superior and inferior medial palpebral arteries
- one above and one below medial palpebral ligament
- anastomose with lateral palpebral arteries
- supply portion of eye lid
81
What are the two terminal branches of the ophthalmic artery?
Supratrochlear and dorsonasal artery
82
Perforated orbital septum above trochlear for superior oblique muscle
Supratrochlear artery
83
What does the supratrochlear exit the orbit with
Suprartochlear nerve
84
What supplies blood to the skin of the medial forehead and scalp?
Supratrochlear artery
85
What does the supratrochlear artery anastomose with
Supraorbital artery, contralateral supratrochlear artery, and anterior temporal artery (branch of external carotid)
86
Perforated orbital septum below trochlea for superior oblique muscle, but above medial palpebral ligament
Dorsonasal artery
87
How does the dorsonasal artery course and what does it supply?
- courses along the side of the nose
- supplies lacrimal sac
- anastomoses with angular artery, a continuation of the facial artery, which is a branch of the external carotid artery
88
Nasofrontal artery
- part of the ophthalmic artery
- lies outside muscle cone
- located along medial wall between anterior ethmoidal artery and trochlea of superior oblique muscle
- gives rise to supratrochlear artery and dorsonasal artery
89
What technically gives rise to the dorsonasal artery and the supratrochlear artery?
Nasofrontal artery
90
What are the branches of the external carotid artery that supply the orbit?
- facial
- infraorbital
- superficial temporal
91
Facial artery
- branch of external carotid
- loops around margin of mandible
- ascends face
- changes name at all of nose to angular artery
- supplies lacrimal sac
- anastomoses with the infraorbital artery and dorsonasal artery at the medial canthus
92
The infraorbital artery is a branch of what?
Maxillary artery
93
Where does the maxillary artery give off the infraorbital branch?
Inside the pterygopalatine fossa
94
How does the infraorbital artery enter the orbit?
Through inferior orbital fissure where it passes through the inferior orbital fissure as the infraorbital artery
95
How does the infraorbital artery run?
- Follows infraorbital nerve through the inferior orbital groove and canal
- emerges on the maxillary bone via infraorbital foramen
96
What does the infraorbital artery supply?
Inferior rectus, inferior oblique, lower lid and cheek
97
What does the infraorbital artery anastomose with?
Angular artery and dorsonasal artery
98
What is the terminal branch of the external carotid artery?
Superficial temporal artery
99
How does the superficial temporal artery course
Upward behind the ramus of the mandible to the temporal fossa
100
What does the superficial temporal artery give off
The anterior temporal artery that will anastomose with branches from the supraorbital and supratrochlear arteries
101
What does the superficial temporal artery supply
Lateral region around the orbit
102
Ocular and orbital venous drainage system
- tortuous
- no valves
- freely anastomose
- direction of blood flow is related to head posture and gravity
103
What is different about veins in the head compared to the rest of the body?
They do not have veins, blood flow is related to head posture and gravity
104
What drains the retina
Central retinal vein
105
How does the ventral retinal vein exit the eye
Through the optic disc via the lamina cribrosa
, travels in center of optic nerve, crosses subarachnoid space and pierces the dura of optic nerve and exits with central retinal artery
106
Where does the central retinal artery drain to?
Superior ophthalmic vein or cavernous sinus
107
What drains the choroid?
Vortex veins
108
How many vortex veins are there?
4-7 vortex veins located just posterior to the equator
| -at least one vortex vein per quadrant
109
What drains the bulbar conjunctiva?
Anterior ciliary veins
110
Where does the anterior ciliary vein drain into?
Muscular veins, which in turn drain to superior ophthalmic vein
111
What drains the lower cheek and lower eyelid?
Infraorbital vein
112
How does the infraorbital vein enter the skull
Via the infraorbital foramen
113
How does the infraorbital vein drain
Via the inferior orbital fissure to the pterygoid venous plexus
114
What is the largest vein in the orbit?
Superior ophthalmic vein
115
How is the superior ophthalmic vein formed?
By joining of supraorbital and angular vein
116
How does the superior ophthalmic vein course
Posterior in orbit picking up numerous tributaries central retinal vein and upper two vortex veins and crosses lateral under superior rectus
117
Where does the superior ophthalmic vein exit?
Above lateral rectus muscle and annular tendon of Zinn via superior ethmoidal orbital fissure
118
Where does the superior ophthalmic vein drain to
Cavernous sinus in middle Cranial Fossa
119
This forms from tributaries on the floor of the orbit
Inferior ophthalmic vein
120
What does the inferior ophthalmic vein drain?
Inferior rectus, inferior oblique, lateral rectus, lower conjunctiva, lacrimal sac, and lower vortex veins
121
Course of inferior ophthalmic vein
Varies as it may drain to the pterygoid venous plexus, superior ophthalmic vein, or cavernous sinus
122
This anastomoses with supraorbital and supratrochlear veins and drains to the facial vein
Angular vein
123
When does he angular vein become the facial vein
After it passes the ala of the nose
124
Facial vein drains where
Picked up tributaries from veins of face, including infraorbital vein and drains into internal jugular vein
125
Dural venous sinus situated on both sides of the body of the sphenoid bone
Cavernous sinus
126
How does the cavernous sinus run
From the superior orbital fissure (anterior) to the petrous portion of the temporal bone (temporal)
127
What does the cavernous sinus receive
Superior and inferior ophthalmic veins
128
Where does the cavernous sinus drain to
Internal jugular vein via the jugular foramen
129
Ocular lymphatic drainage
None
130
Orbital lymphatic drainage
- lacrimal gland only
| - follows lymphatic pathway from lateral part of palpebrae to preauricular lymph nodes
