6. Sensory Nerves
*The Nasociliary
nerve--> long
posterior ciliary nerve
(globe) , senosry fibers
through ciliary
ganglion, and nasal
mucosa, skin at tip of
nose.
(Hutchinson’s Sign)
7. Ciliary Ganglion
• 1.5 mm Lateral to the
apical optic nerve.
• Sensory branches from
nasociliary nerve.(pass
through only).
• Parsympathetic fibers
from (ciliary body and
sphincter pupillae).
(synapse)
• Sympathetic fibers
from ICA for iris
dilator muscle. (pass
through only)
11. Infra-orbital Nerve
• Main continuation of V2.
• Infra-orbital groove (surgical
land mark)
• Provides sensation of lower
lid,cheek, medial upper lip.
• * Zygomatic branch-->
zygomaticomaxillary, and
zygomaticfacial to innervate
zygoma and lateral orbit.
12. Pterygopalatine
Ganglion (PG)
* Parasympathetic
ganglion of the head and
neck.
* Greater Palatine nv.
->Palatine nerve-> PG->
Zygomaticotemporal->
Lacrimal nv.
13. Motor Nerves
Oculomotor
Oculomotor
• Exits brain stem between post-
communicating and superior cerebellar
artery.
• Lateral wall of cavernous sinus and divides
into superior and inferior division.
• Through SOF through annulus of Zinn.
21. Ophthalmic Artery
• Only ICA branch that
enters the orbit.
• Aastomoses with ECA
branches.
• Enters orbit inferolateral
to optic nerve.
• At orbital Apex
Branches: to retina
(CRA) and choroid
(PCA).
• Short PCA : 15-20 from
LPCA pierce sclera and
supply ONH and
choroid.
23. Branches of External
Carotid Artery
* Orbital circulation has high
degree of collateralization with
ECA .
* Supra-orbital and
Supratrochlear<--> Superficial
temporal Art.
* Dorsonasal <--> Angular Art.
*Ant and Post. Ethmoidal <-->
Sphenopalatine
* Lacrimal Art. <--> Middle
Meningeal Art.
25. Venous Outflow
• Valveless veins which drain posteriorly.
• The Superior orbital vein (SOV) is a
confluence of angular, naso-frontal, and
Supra-orbital vein.
• Directed from medial to lateral.
• Starts near trochlea, medial to SR--
>beneath SR--> Lateral to SR--> SOF.
26. Inferior Orbital Vein
• Drains posteriorly (anastomoses with
Supra-orbital vein)--> Inferior orbital
fissure--> into Pterygoid venous plexus and
Inferior orbital fissure.
29. Orbital Vasculature
• Ophthalmic artery (1st Branch of ICA).
• Primary blood supply (small contribution
from ECA: maxillary and middle meningeal
arteries).
• Branches variable.
• Ophthalmic artery enters the optic canal.
30. Branches of
Ophthalmic Artery
• Central retinal artery (Retina).
• Long posterior ciliary arteries (Choroid) ; 1)Short
Posterior Ciliary Arteries (15-20) supply choroid and
optic nerve head. 2) Long Post Cililary (2) for Iris and
Ciliary body.
• Lacrimal artery. (gland) recurrent meningeal art.
anastomosis
• Anterior & Posterior ethmoidal.
• Muscular Branches (divides into 2 long anterior ciliary
arteries except LR has 1 only).--> anastom with long
post. ciliary arteries (supply anterior segment).
34. Maxillary Artery
• Infra-orbital artery is the terminal end.
• Muscular branches to IR and IO.
• Anastomoses with angular artery and
inferior palpebral vessels.
37. Venous Drainage of
Orbit
• Valveless superior and inferior ophthalmic veins.
• Confluence of the angular, supraorbital, and
supratrochlear veins form superior ophthalmic
vein.
• Inferior ophth vein receives tribuatries from
muscular, vortex, and medial and lateral collateral
veins.
• IOV communicates with pterygoid plexus via IOF.