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84 Cards in this Set
- Front
- Back
what bones form the margin of the orbit?
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frontal bone
zygomatic bone maxillary bone |
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what bones form the medial wall of the orbit?
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lacrimal bone
ethmoid bone |
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what bones form the lateral wall of the orbit?
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zygomatic bone
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what bones form the floor of the orbit?
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maxillary bone
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what bones form the roof of the orbit?
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orbital plate of the frontal bone
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what forms the deep wall of the orbit?
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greater and lesser wings of the sphenoid bone
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where is the superior orbital fissure?
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between the greater wing and lesser wing of the sphenoid bone
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where is the inferior orbital fissure?
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between the maxillary bone and the greater wing of the sphenoid bone
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where does the optic canal lie?
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in the root of the lesser wing of the sphenoid bone
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how do the medial walls of the orbit relate to one another? the lateral walls?
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medial walls are parallel
lateral walls diverge |
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what forms the fibromuscular cone around the eyeball?
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continuous fascial sheath around and between the muscles of the eye
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what fills the interior of the fibromuscular cone of the eye?
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fat
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where is the levator palpebrae superioris?
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superior to the cone of the eye, below the roof of the orbit
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what are the attachments of the levator palpebrae superioris?
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from back of orbit
to upper eyelid |
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what supplies innervation to the levator palpebrae superioris?
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CN III
sympathetic nerves |
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what is the result of a lesion of one of the nerves supplying the levator palpebrae superioris?
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ptosis
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what is ptosis?
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drooping of the eyelid
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what is the purpose of the lacrimal fluid?
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moistens and lubricates the conjunctiva and cornea
provides nutrients and dissolved oxygen to the cornea |
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what conveys lacrimal fluid from the lacrimal gland to the lacrimal sac?
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lacrimal ducts
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what are lacrimal canaliculi?
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tubes that drain the lacrimal fluid to the lacrimal sac, starting from the punctum
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what is a punctum?
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minute orifice through which the lacrimal canaliculi open onto the interior surface of the eyelid
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what drains lacrimal fluid from the lacrimal sac?
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nasolacrimal duct
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where does the nasolacrimal duct go?
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from the nasolacrimal sac to the inferior nasal meatus (back of nose and throat)
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how are parasympathetic secretomotor fibers carried to the lacrimal gland?
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facial nerve (pre) -> greater petrosal nerve (pre) -> nerve to pterygoid canal (pre) -> pterygopalatine ganglion (syn) -> zygomatic n. (post) -> lacrimal n. (post) -> lacrimal gland
pre=preganglionic syn=synapse post=postganglionic |
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from what nerve is the zygomatic nerve a branch?
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maxillary division of the trigeminal nerve (V2)
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from what nerve is the lacrimal nerve a branch?
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ophthalmic division of the trigeminal nerve (V1)
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what is the function of the lateral rectus muscle?
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abductor of the eye (turns pupil laterally)
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what is the function of the medial rectus muscle?
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unilaterally - adductor of the eye (turns pupil medially)
bilaterally - convergence of gaze (focuses eyes on nearby object) |
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what is the function of the superior rectus muscle?
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turns the pupil superiorly and medially
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what is the function of the inferior rectus muscle?
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turns the pupil inferiorly and medially
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where does the superior oblique muscle of the eye run?
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along medial wall to reach trochlea, looping posteriorly through a fascial sling before being attached to the the eyeball (deep to superior rectus muscle)
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what is the function of the superior oblique muscle of the eye?
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incyclotorsion (primary)
depression (secondary) abduction (tertiary) |
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where does the inferior oblique muscle of the eye run?
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from floor of orbit laterally below the eyeball, attaching to the eyeball laterally
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what are the functions of the inferior oblique muscle of the eye?
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excyclotorsion (primary)
elevation (secondary) abduction (tertiary) |
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what muscles are required to look straight up?
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superior rectus
inferior oblique |
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what muscles are required to look straight down?
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inferior rectus
superior oblique |
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what muscles are required to look to the left?
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left lateral rectus
right medial rectus |
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from what artery does the ophthalmic artery arise?
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internal carotid artery
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from what artery does the central artery of the retina arise?
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ophthalmic artery
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where does the central artery of the retina travel?
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enters the optic nerve, travels near its center to the eyeball, and after going into the eyeball, divides into nasal and temporal branches (with corresponding veins)
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what are the arteries which can be seen with an ophthalmoscope?
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nasal and temporal branches of the central artery of the retina
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what are the two end branches of the ophthalmic artery?
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dorsal nasal artery
supratrochlear artery |
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what are the branches of the ophthalmic artery?
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central retinal artery
lacrimal artery posterior ciliary arteries supraorbital artery posterior ethmoidal artery anterior ethmoidal artery medial palpebral artery dorsal nasal artery supratrochlear (frontal) artery |
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where does the lacrimal artery run?
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along the lateral wall of the orbit
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what is supplied by the lacrimal artery?
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lacrimal gland
eyelids |
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how many long posterior ciliary arteries branch from the ophthalmic artery?
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2
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how many short posterior ciliary arteries branch from the ophthalmic artery?
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many
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what is supplied by the posterior ciliary arteries?
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choroid inside the eyeball
short - back of eyeball long - corneoscleral junction |
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where do long posterior ciliary arteries break up into branches?
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corneoscleral junction
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from what arteries do the anterior ciliary arteries branch?
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lacrimal artery and/or posterior ciliary arteries (long or short)
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what is supplied by the anterior ciliary arteries?
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choroid in the front of the eyeball
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what is supplied by the supraorbital artery?
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scalp
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what is supplied by the anterior and posterior ethmoidal arteries?
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ethmoidal air cells
upper part of nasal mucosa (posterior only) |
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what branch from the ophthalmic artery continues into the nasal cavity?
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posterior ethmoidal artery
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into what do the veins of the orbit drain?
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superior ophthalmic vein
inferior ophthalmic vein |
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with what do the superior and inferior ophthalmic veins communicate?
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cavernous sinus
pterygoid plexus of veins |
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what is an ethmoidal air cell?
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paranasal sinus
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where does CN IV enter the orbit?
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above the fibrous ring (outside of muscular cone)
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where does CN IV enter the superior oblique?
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the upper border of the superior oblique
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where does CN VI go immediately after entering the orbit?
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enters within the muscular cone and immediately turns lateral to enter the lateral rectus
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where are the two branches of CN III within the orbit?
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above and below the nasociliary nerve within the muscular cone
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what is innervated by the superior branch of CN III?
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rectus superioris
levator palpebrae superioris |
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what is innervated by the inferior branch of CN III?
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rectus medialis
rectus inferioris obliquus inferioris |
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what nerve carries preganglionic parasympathetic fibers, which are destined for the eyeball?
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oculomotor branch to inferior oblique muscle
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from where do the preganglionic parasympathetic fibers for the eyeballs arise?
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Edinger-Westphal nucleus in the midbrain
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where do parasympathetic fibers for the eyeball synapse?
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ciliary ganglion
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what carries postganglionic parasympathetic fibers to the back of the eyeball?
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short ciliary nerves
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what is supplied by the postganglionic parasympathetic fibers of the short ciliary nerves?
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ciliaris muscle
sphincter papillae |
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from where do all sensory nerves of the orbit branch?
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ophthalmic division of the trigeminal nerve (V1)
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what are the branches of CN V in the orbit?
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frontal nerve
lacrimal nerve nasociliary nerve |
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where do the branches from CN V enter the orbit?
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frontal nerve - above fibrous ring
lacrimal nerve - above fibrous ring nasociliary nerve - within fibrous ring |
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on what does the frontal nerve lie?
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directly below the roof of the orbit, the frontal nerve lies on the levator palpebrae superioris
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what are the branches of the frontal nerve?
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supraorbital nerve
supratrochlear nerve |
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what is supplied by the supraorbital nerve?
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scalp
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what is supplied by the supratrochlear nerve?
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scalp
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what is innervated by the lacrimal nerve?
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sensory to skin of eyelids
postganglionic parasympathetic secretomotor fibers to lacrimal gland |
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to what artery is the nasociliary nerve's course similar? in what ways is it different?
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ophthalmic artery
short ciliary nerves from ciliary ganglion, not nasociliary nerve lacrimal nerve is a separate branch from ophthalmic division |
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what nerve gives rise to the two long ciliary nerves entering the back of the eyeball?
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nasociliary nerve
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what type of fibers are carried by the long ciliary nerves?
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postganglionic sympathetic fibers for dilator pupillae
sensory fibers for cornea |
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what is supplied by the sympathetic fibers of the long ciliary nerves?
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dilator pupillae
cornea |
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from where do the postganglionic sympathetic fibers of the long ciliary nerves arise?
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superior cervical ganglion
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from which nerve is the posterior ethmoidal nerve a branch?
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nasociliary nerve
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from which nerve is the anterior ethmoidal nerve a branch?
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nasociliary nerve
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what are the two terminal branches of the nasociliary nerve?
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anterior ethmoidal nerve
infratrochlear nerve |