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201 Cards in this Set

  • Front
  • Back
The orbit contains _____, ____, ____, & ____.
eyeball, muscles & nerves that supply eyeball, & lacrimal apparatus
The 4 margins of the orbit are _____, _____, _____, & ____.
supraorbital; lateral; infraorbital; medial
The supraorbital margin is formed by ______.
frontal bone
The lateral margin is formed by ______.
The infraorbital margin is formed by ______.
zygomatic & maxillary bones
The medial margin is formed by ______.
frontal process of maxilla & a little bit of lacrimal bone
The roof of the orbit is formed by ______ & ______.
orbital plate of frontal bone & and some lesser wing of sphenoid posteriorly
The floor of the orbit is 1º formed by the _____. The ___ & ___ contribute a little.
orbital surface of maxillary bone; zygomatic bone & palatine process
The lateral wall of the orbit is formed by _______.
greater wing of sphenoid & zygomatic bone
The medial wall of the orbit is formed 1º by the _____, and somewhat by the _____.
orbital plate of ethmoid bone (thin!, also called lamina papyracia), & lacrimal bone
Which one of the orbital walls is the only one that is thick?
What are the fissures through which objects enter & exit the orbit?
optic canal; sup. & inf. orbital fissure; ant. & post. ethmoidal foramina; lacrimal gland
The optical canal transmit CN ___ & ____ artery.
CN II (optic nerve); opthalmic artery
The opthalmic artery is a branch of _______.
The _____ separates the roof from lateral wall of the orbit.
superior orbital fissure
_______ lies b/tw the greater & lesser wings of the sphenoid bone.
The superior orbital fissure
The superior orbital fissure connects with the ____ cranial fossa.
The superior orbital fissure transmits which MOTOR nerves?
The superior orbital fissure transmits which SENSORY nerves?
V1 (opthalmic nerve)
The ____ vein, which drains the orbit, passes through the orbit.
The ______ separates the floor and the lateral wall.
inferior orbital fissure
The inferior orbital fissure allows the orbit to communicate with ____ & ___.
infratemporal fossa & pterygopalatine fossa
The inferior orbital fissure transmits ____.
infraorbital nerve, artery, & vein
The infraorbital nerve is a continuation of the ______.
The maxillary nerve (V2)changes its name to infraorbital when it enters _____.
inferior orbital fissure
The infraorbital artery is a branch of ______.
maxillary artery
The zygomatic nerve is a posterior branch of ____ that comes off and enters orbit.
V2 (maxillary nerve)
The zygomatic branch is 1º a _______ nerve innervating skin of face & temple.
The infraorbital nerve, artery, & vein run in the ___ before emerging thru ___.
infraorbital groove (floor of orbit); infraorbital fossa
The ____ are found on medial wall of the orbit, close to jxn of frontal & ___ bones.
anterior & posterior ethmoidal foramina; ethmoid
The anterior & posterior ethmoidal foramina transmit _______.
anterior & posterior ethmoidal nerves & vessels
The anterior & posterior ethmoidal nerves are branches of the _____ nerve.
V1 (opthalmic)
The fossa for the lacrimal sac is formed by ____ & ___ bones.
lacrimal & maxillary
The lacrimal gland lies in the ______ corner of the orbit in a ____ of frontal bone.
anterior, superolateral corner; small depression
Where does the nasolacrimal canal (w/duct) begin & end?
begins: floor of orbit
ends: nasal cavity
Where is the common tendinous ring found?
In the apex of the orbit
The nasociliary nerve is a branch of ____ & passes through ____.
V1; superior orbital fissure
Superiorly, the orbit may be related to _______.
frontal air sinus (frontal bone forms orb. plate, which is roof of orbit)
The front of the brain lies on what structure?
orbital plate of the frontal bone
____ separates the floor of the orbit from the maxillary sinus (inferiorly).
A thin plate of bone
A blowout fracture occurs _____ & may cause the eye to _____, causing what?
floor of orbit; sink into maxillary sinus, causing double vision
Double vision is also refered to as ______.
Infections from the maxillary sinus can spread through _____.
the floor of the orbit--affects orbital contents
Tiny spaces in the ethmoid bone are also called _____.
ethmoidal air cells (infections may arise here)
A very thin medial wall of the orbit may be a potential danger because _______.
when cleaning/irrigating ethmoidal air cells, optic nerve may be damaged due 2 thin wall
The lateral wall of nose, sometimes used for __, is associated w/what cranial fossa?
surgery; middle cranial fossa (which contains temporal lobe)
The _____ part of the retina is the part with the photo-receptors (rods & cones).
_____ converges at the optic disk (optic papilla).
A layer of ganglion cell axons
After converging at the optic disc, the axons turn ____ & constitute the OPTIC n.
posteriorly (leave retina)
There are no rods or cones in the _______; therefore, it is called the ______.
retina; blind spot
Developmentally, the retina is an outgrowth of ______.
the brain
Since the retina is an outgrowth of the brain, the optic nerve is considered __.
nerve tract (connects one part of brain with another)
The retina is surrounded by how many layers of meninges?
all 3
The _____ & _____ are contained within the optic nerve.
cerntral artery & vein of the retina (they therefore pierced all 3 menin. layers)
The outer sheath of optic nerve is formed by ____; inner sheath formed by ____.
outer: dura & arachnoid mater;
inner: pia mater
Extension of subarachnoid space that surrounds optic nerve is called ______ space.
intervaginal (subarachnoidal)
The intervaginal space of the optic nerve contains _____.
If CSF pressure rises (i.e. brain tumor), what can be compromised?
optic nerve
The central vein of the retina is very vulnerable to _______. Why?
CSF pressure; it's thin-walled & can be easily compressed
Increased pressure will cause ______ to swell.
optic disc
Swelling of the optic disc/papilla is a.k.a. _______.
Papilledema could be a diagnostic sign related to ____.
brain tumors & intracranial pressure increase
The optic nerve is ___ (GVA, GVE, SVA, SVE....).
SSA Special Somatic Afferent
What are the 2 sets of muscles in the eye?
intrinsic & extrinsic
Intrinsic muscles of the eye are _____ muscle & under ____ control.
smooth; involuntary
The _____ is the white of the eye.
The lens is a ______ shape.
The ciliary body of eye contains the ______.
The ciliary is attached to the lens by ______.
ciliary zonule (a.k.a. suspensory ligament of the lens)
What does the contraction of the cilary muscle do to the ciliary zonule (susp. lig.)?
RELAX the tension in ciliary zonule (susp. lig. of lens)
What does the contraction of the cilary muscle do to the lens?
allows it to BECOME MORE SPHERICAL in shape; & in turn SHORTENS FOCAL LENGTH
What does the contraction of the cilary muscle do to one's vision?
allows you to focus on nearby objects; process called ACCOMODATION
When looking at objects far away, describe the shape of the lens.
FLATTENED (ciliary zonule tension is tighter)
The iris of the eye contains which 2 muscles?
sphincter & dilator muscles of pupil
The contraction of _____ causes the pupil to become smaller & constrict.
sphincter pupili
The pupil is dilated by the ______.
dilator pupili
The _____ muscle allows less light to reach the eye. How?
sphincter pupili; it contracts & constricts pupil
_____ = making pupil smaller;
_____ = making pupil larger;
(hint:myosis is shorter word)
The sphincter, dilator, & ciliary muscles are all under ______ control.
The ______ & _____ are under parasympathetic control.
sphincter & ciliary muscles
The dilator pupili muscle is under _____ control.
The cell bodies of PS, presynap. neurons of eye are in ______.
midbrain (Edenger-Westphal nucleus/Accessory Oculomotor nucleus)
The axons of PS, presynap. cell bodies leave in CN ___.
3 (oculomotor)
When CN 3 enters the orbit, it gives off ____ branch.
oculomotor root of ciliary ganglion
Presynap. fibers of PS travel in oculomotor root & go to _____ ganglion.
Synapse of PS fibers for intrinsic eye muscles occurs in ____.
ciliary ganglion
Postsynap. fibers (PS) from ciliary ganglion travel thru _____ to reach the eyeball.
SHORT ciliary nerves
Short ciliary nerves travel in the ___ of the eyeball to reach ____ & cause constriction.
wall; sphincter pupili & ciliary muscle
Presynap. symp. neurons are found in ______.
lateral horns of T1-T3
Presynap. symp. neurons leave the spinal nerves via ____ & ascend to ______.
white rami comunicantes;
cervical sympathetic trunk
Synapse of intrinsic eye muscle sympathetic neurons occurs in _____.
superior cervical ganglion (uppermost ganglion at base of skull)
Postsynap. symp. neurons travel up ______ and form ____ plexus.
internal carotid artery (ICA); IC plexus
SOME ICA fibers (postsyn. symp.) leave IC plexus & travel w/____.
Where does V1 lie?
in the dura mater of the lateral wall of the cavernous sinus
V1 (w/ SOME postsyn. symp. fibers) enters the ORBIT & gives off ______ nerves.
LONG ciliary
The LONG ciliary nerves convey ______ fibers to the eyeball, which do what?
postsynaptic sympathetic (only some from the IC plexus); DILATE eyeball
SOME postsyn. symp. neurons travel along the __ artery & exit ciliary ganglia via ____.
opthalmic artery;
sympathetic root
The postsyn. symp. fibers pass that pass thru ciliary gang use __ to reach dilator pupila.
SHORT ciliary nerves
All postsynaptic, sympathetic fibers will involve the _____ plexus.
IC (Internal Carotid)
LONG ciliary nerves contain ______ neurons (postsynaptic PS or sympathetic?).
SHORT ciliary nerves contain ______ neurons (postsynaptic PS or sympathetic?).
The extrinsic muscles of the eye are under ____ control. What action do they have?
VOLUNTARY; move eyeball & eyelids
Levator palpebrae superioris inserts into ______.
skin of upper eyelid & superior tarsal plate
The levator palpebrae superioris is innervated by _____.
CN3 (oculomotor nerve)
It's a striated muscle
The _____ muscle also elevates the eyelid.
superior tarsal
The superior tarsal is under ____ control by _____ fibers.
autonomic; sympathetic
The superior tarsal is ____ muscle that inserts into _____.
superior tarsal plate
If there is damage to the oculomoter n., _____ may result.
drooping of eyelid (ptosis)--caused by paralyis of sup. tarsal or lev.palp. sup.
The optic nerve takes a _____ course, allowing for what?
wavy; free movement of the eyeball
The 4 rectus muscles of the eye are ____, ____, ____, & _____.
superior, inferior, lateral & medial
The rectus muscles all originate from ____.
comon tendonous ring (common annular ring)
The rectus muscles pass ___. Then, they diverge & insert into ______.
anteriorly; anterior part of sclera, just behind jxn w/ cornea
There are ____ oblique muscles. What are they?
2; superior, inferior
The superior oblique originates ____ & inserts into _____.
sphenoid bone (post. orbit); posterior lateral portion of sclera
The superior oblique starts post. & runs along ____ wall.
Along the medial wall, the sup. oblique passes through a cartilaginous pulley, ____.
After passing over the trochlea, the sup.oblique runs ___ & attaches into ___.
posteriolateraly; lateral part of sclera
When the sup. oblique is contracted, _____ is its functional origin.
The inferior oblique arises from ____ & inserts into ____.
anterior medial floor near lacrimal canal; sclera (it runs posterolateral)
Which extrensic eye muscle has a totally distinct origin?
inferior oblique
When is the eye in primary position?
when looking at a distant object
The orbital axis passes from ____ to ____.
apex of orbit to base of orbit
The eyeball has 3 major axes that move & are perpindicular--what are they?
vertical, transverse, anterior-posterior
____ & ____ occur on the vertical axis.
ABduction & aDduction
The _______ muscles cause aDduction. (hint: pass medially to axis)
medial rectus, superior rectus, inferior rectus
The _______ muscles cause aBduction. (hint: cross axis on lateral side)
lateral rectus, superior & inferior OBLIQUES
____ & ____ occur on the transverse axis.
Elevation & depression
___ & ____ cause elevation.
Superior rectus & inferior oblique
___ & ____ cause depression.
inferior rectus & superior oblique
____ & ____ occur around the anterior-posterior axis.
Intorsion & extorsioin
In _____, the superior pole of the eye moves ____ midline.
intorsion; towards
In _____, the superior pole of the eye moves away from ____.
extorsion; away from midline
___ & ____ muscles are responsible for intorsion of eye.
superior oblique; superior rectus
___ & ____ muscles are responsible for extorsion of eye.
inferior oblique; inferior rectus
Intorsion & extorsion come about when you ____ your head & the eyes _____.
tilt; converge & move in concert to one another
How do you get elevation of eyeball (contraction of what muscles)?
superior & inferior RECTUS & OBLIQUE muscles (they all cancel each other out)
If the eye is already aDducted, what muscle causes elevation of eyeball?
inferior oblique
Why is the inferior oblique a good elevator when eye is adducted?
B/c the pull of it is directly perpindicular to transverse axis
If the eye is aBducted, ____ is what elevates it.
superior rectus
The innervation of the eye can be thought of as SO_, LR_, R__
SO4; LR6; R3
The SO (superior oblique) is innervated by _____
hint: it's the only muscle to pass thru trochlea
The LR (lateral rectus) is innervated by ____.
CN6 runs through _____, & is found on the ____ side of the lateral rectus muscle.
superior orbital fissure; MEDIAL side of LR!
Injury to the abducent nerve will cause _____.
eye to turn inward (b/c LR is paralyzed & tone of MR takes over to cause aDduction)
Paralysis of any eye muscle will result in _____.
diplopia (double vision)
Besides the SO & LR, all other extrensic eye muscles (R) are innervated by ____.
CN3 splits into ___ & ___ before entering the superior orbital fissure.
superior & inferior divisions, but both enter the sup. orbital fissure
The superior division of CN 3 innervates ___ & ____.
superior rectus & levator palpebrae superioris
The inferior division of CN 3 innervates ___, ____, & ____.
inferior rectus, inferior oblique, & medial rectus
(hint: IIM)
The ____ is the connective tissue lining of the orbit.
The sensory nerves to the orbit are branches of ____.
V1 (opthalmic nerve)
V1 arises from _____ in the _____.
trigeminal ganglion; middle cranial fossa
After leaving ganglion, V1 travels toward supra orbital fissure embedded in ______.
dura mater of the lateral wall of the cavernous sinus
V1 is what kind of nerve? (G, S, V, E, A...)
GSA--purely sensory
It's possible for ___ fibers from int. carotid plexus to join V1 & innervate ___?
sympathetic; dilator pupili
_____ ciliary nerves originate from V1.
LONG ciliary nerves originate from _____.
CN3 (through oculomotor root going to ciliary ganglion)
Before V1 enters opthalmic fissure, it splits into what 3 terminal branches?
NFL-nasociliary; frontal; lacrimal
The frontal nerve is more or less a continuation of the _____. Where is it found?
opthalmic nerve; just above levator palpebrae superioris
The frontal nerve splits into _____ (more medial) & ______ (more lateral).
supratrochlear (medial)
supraorbital (lateral)
The supraorbital branch of the frontal nerve splits into ____ & ____ branches.
medial & lateral branches
The supraorbital & supratrochlear nerves are _____ & supply ______.
General Sensory; skin of upper eyelid, forehead, & scalp
Apart from skin, the supraorbital nerve also innervates the lining of ___.
the frontal air sinus
The lacrimal nerve runs on the ____ wall of the orbit above what muscle?
lateral; lateral rectus
The lacrimal nerve runs to the ______, and also has a ____ branch.
lacrimal gland
palpebral branch (innervates skin of eyelid)
Before the lacrimal nerve reaches lacrimal gland, it picks up ____ fibers.
The PS (post-synaptic) fibers that join lacrimal nerve come from ______.
the zygomatic nerve
The nasociliary nerve runs obliquely,___-___(med./lat), just ___ to the optic nerve.
lateral to medial; just SUPERIOR
The nasociliary nerve gives off _____ ciliary nerves (long or short?).
LONG ciliary nerves
Long ciliary nerves have ___ fibers that go to the eyeball for _____ .
GSA; general sensation, NOT pain!
If you touch the cornea, it's painful b/c of what nerve?
long ciliary nerves from nasociliary
The long ciliary nerves have post-synaptic sympathetics in them from ______ (where?).
internal carotid plexus (they're going to the dilator pupili
Anterior & posterior ethmoidal nerves come off of ______.
The anterior & posterior ethmoidal nerves leave the orbit through ________.
anterior & posterior foramen
What do the anterior & posterior ethmoidal nerves innervate together?
mucosa lining of ethmoidal air cells
What does the anterior ethmoidal nerve innervate?
gen. sensation in nose; then emerges on nose & supplies skin of lower external nose
The anterior ethmoidal nerve is a terminal branch of the ___ that enters the ______.
nasociliary; nasal cavity
When the anterior ethmoidal nerve exits the nose, it is called the _______.
external nasal nerve
Another terminal branch of the nasiciliary is the _____.
infratrochlear nerve
What does the infratrochlear nerve innervate?
lacrimal sac; general sensation for skin on upper 1/2 of nose
The ______ is the chief blood supply of the orbit.
opthalmic artery
The opthalmic artery is a branch of _____, which lies in the ______.
internal carotid artery (ICA); middle cranial fossa
How does the opthalmic artery enter the orbit?
With optic nerve through optic canal
The opthalmic artery runs obliquely (lateral to medial), parallel to ______.
nasociliary nerve
The opthalmic artery gives off numerous branches, namely ____ & _____.
orbital & ocular branches
The ____ branches of the opthalmic artery supply the eye itself.
ocular branches
The posterior ciliary arteries (ocular branch of opthalmic a.) supply ______.
the eyeball
The most important ocular branch of the opthalmic artery is ______.
central artery of the retina
The central artery of the retina pierces the ____ & is sole arterial supply to ___.
optic nerve;
The orbital branches of the opthalmic artery include ___, ___, ____, ____, & ____.
lacrimal, supratrochlear & supraorbital, ethmoidal, muscular, dorsal nasal aa
The lacrimal artery of the opthalmic goes to the ______.
lacrimal gland
The supratrochlear & supraorbital aa. of opthalmic supply the _____.
The ethmoidal arteries of opthalmic supply blood to ______.
nasal cavity
The muscular branches of the opthalmic supply ______.
muscles of the orbit
The dorsal nasal artery of the opthalmic supplies the _________.
dorsum of the nose
The superior & inferiro opthalmic veings drain the orbit into ___ (posteriorly).
cavernous sinus
_____ veins drain the choroids of the eye. They drain into the _____.
vorticose veins;
opthalmic vein
Anteriorly the opthalmic vein communicates with _____.
angular vein
The communication between angular vein & opthalmic vein is a path for ______.
spread of infection from the face to the cavernous sinus
The inferior opthalmic vein communicates with the _____ through the _____.
pterygoid venous plexus; inferior orbital fissure
The pterygoid venous plexus is a way that _____ can spread.