Exam (elaborations)
Fundamentals OKAP Questions And Answers
- Course
- Institution
Fundamentals OKAP Questions And Answers Fundamentals OKAP Questions And Answers Fundamentals OKAP Questions And Answers
[Show more]
Content preview
Fundamentals OKAP QuestionsTotal volume of orbit - ANS 30 mL
Average orbital entrance diameter - ANS 35 mm in height, 45 mm in width (widest approx 1 cm
behind anterior orbital margin)
Depth of the orbit - ANS 40-45 mm
Bones that make up the orbital margin/rim - ANS Frontal bone (superior, top medial, lateral)
Posterior lacrimal crest of lacrimal bone (bottom medial)
Anterior lacrimal crest of the maxillary bone (bottom medial)
Maxillary bone (inferior)
Zygomatic bone (inferior, lateral)
Bones that make up the orbital roof - ANS Orbital plate of frontal bone
Lesser wing of the sphenoid bone
Bones that form the medial wall of the orbit - ANS Frontal process of maxillary bone
Lacrimal bone
Orbital plate of the ethmoid bone
Lesser wing of the sphenoid bone
Lamina papyracea - ANS Orbital plate of ethmoid bone that makes up the largest portion of the
medial orbital wall
Most common site of fracture following blunt trauma to orbit - ANS Lamina papyracea
What is the most direct path to the optic nerve - ANS Along the medial wall
Rule of 12s - ANS Distance from anterior lacrimal crest to the anterior ethmoidal foramen is 24 mm
,Distance from anterior ethmoidal foramen to posterior ethmoidal foramen is 12 mm
Distance from posterior ethmoidal foramen to the optic canal is 6 mm
Bones that form the floor of the orbit (roof of the maxillary sinus) - ANS Orbital plate of the maxillary
bone
Palatine bone
Orbital plate of the zygomatic bone
What is the only extra ocular muscle that does not originate from the orbital apex - ANS Inferior
oblique muscle
Whitnall tubercle - ANS Lateral orbital tubercle
Small elevation of orbital margin of zygomatic bone, lies approximately 11 mm below the
frontozygomatic suture.
Site of attachment for the following structures:
-Ligament of the lateral rectus muscle
-Suspensory ligament of the eyeball (Lockwood suspensory ligament)
-Lateral canthal ligament
-Lateral horn of the levator aponeurosis
What is contained in the optic canal - ANS optic nerve
Ophthalmic artery
Sympathetic fibers from the carotid plexus
What bone does the optic canal pass through - ANS Lesser wing of the sphenoid
What does the supraorbital foramen/notch contain - ANS Blood vessels
Supraorbital nerve (branch of frontal nerve which branches off of CN5 (V1))
,What does the anterior ethmoidal foramen contain - ANS Anterior ethmoidal vessels and nerve
What does the infraorbital canal contain - ANS Infraorbital nerve (branch of CN5, V2 aka maxillary
division)
Superior orbital fissure (contains and location) - ANS Above Annulus of Zinn:
-Lacrimal nerve of CN5 V1
-Frontal nerve of CN5 V1
-CN 4 (trochlear nerve)
-Superior ophthalmic
Within the Annulus of Zinn:
-Superior and inferior divisions of CN3 (oculomotor nerve)
-Nasociliary branch of CN5 V1 (which also carries postganglionic sympathetic fibers in route to the
ciliary ganglion)
-CN6 (abducens nerve)
Located between greater and lesser wings of the sphenoid
Lateral to optic foramen
Annulus of Zinn - ANS Tendinous ring formed by the common origin of the rectus muscles
Inferior orbital fissure contains - ANS Transmits the infraorbital and zygomatic branches of CN5 V2
and orbital nerve from the pterygopalatine ganglion and sometimes the inferior ophthalmic vein
What does the inferior ophthalmic vein drain into - ANS Into the cavernous sinus
Fovea ethmoidalis - ANS Forms the roof of the ethmoid sinuses and is a lateral extension of the
cribiform plate
If damaged, can cause CSF leakage and intracranial injury
, Ciliary ganglion - ANS Located 1 cm in front of the annulus of Zinn
Receives innervation from the sensory root (from nasociliary branch of CN5 V1, contains sensory
fibers), motor root (arises from inferior division of CN3 and carries preganglionlic parasympathetic
fibers from Edinger-Westphal nucleus) and the sympathetic root (postganglionic fibers originating
from the superior cervical canclion because they course superiorly with the internal carotid artery)
Only the parasympathetic fibers synapse in the ciliary ganglion
Short ciliary nerves - ANS Arise from the ciliary ganglion
Enter the sclera around the optic nerve and pass anterior between the choroid and the sclera to the
ciliary muscle
Then form a plexus with the long ciliary nerve that supplies the cornea, ciliary body and the iris
Both sensory and motor nerves
Superior tendon of the annulus of Zinn - ANS Gives rise to the superior rectus muscle, portions of
lateral and medial rectus muscles
Inferior tendon of the annulus of Zinn - ANS Gives rise to the inferior rectus muscle and portions of
the lateral and medial rectus muscles
Where does the elevator palpebrae superioris muscle arises from - ANS The lesser wing of the
sphenoid bone at the apex of the orbit, just superior to the annulus of Zinn
Where does the superior oblique muscle originate from - ANS The periosteum of the body of the
sphenoid bone, above and medial to the optic foramen
Where does the medial rectus insert - ANS Medially, in horizontal meridian 5.5 from the limbus
Blood supply to medial rectus - ANS Medial (inferior) muscular branch of ophthalmic artery
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lectjoseph. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
80796 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now