Final Flashcards
What bones form the roof of the orbit?
frontal (orbital process), sphenoid (lesser wing)
What bones form the floor of the orbit?
maxilla (orbital process), zygomatic, palatine (orbital process)
What bones form the lateral wall of the orbit?
zygomatic, sphenoid (greater wing)
What bones for the medial wall of the orbit?
maxilla (frontal process), lacrimal, ethmoid (orbital process)
What part of the orbit is formed by the frontal bone?
roof
What part of the orbit is formed by the sphenoid bone?
roof, lateral wall
What part of the orbit is formed by the ethmoid bone?
medial wall
What part of the orbit is formed by the maxilla?
floor, medial wall
What part of the orbit is formed by the zygomatic bone?
floor, lateral wall
What part of the orbit is formed by the palatine bone?
floor
What part of the orbit is formed by the lacrimal bone?
medial wall
Which orbital foramen is in the lesser wing of the sphenoid?
optic canal
Which orbital foramen is bordered by greater and lesser wings of the sphenoid?
superior orbital fissure
Which oribital foramen is in the ethmoid bone?
ethmoidal foramina
What comes though the optic canal?
CN II, opthalmic a.
What comes through the superior orbital fissure?
CN III, IV, V1, VI, superior opthalmic vv.
What comes through the inferior orbital fissure?
infraorbital n.a.v.
What comes through the supraorbital foramen?
supraorbital n.a.v.
What comes through the infraorbital foramen?
infraorbital n.a.v.
What comes through the ethmoid foramina?
ethmoidal n.a.v.
What comes through the nasolacrimal canal?
nasolacrimal duct
What separates the orbit from the anterior cranial fossa?
orbital roof
What separates the orbit from the maxillary sinus?
orbital floor
What separates the orbit from the ethmoid air cells & nasal cavity?
medial wall of orbit
What part of the orbit is strongest?
lateral wall
What is palpebra?
eyelid
What is the palpebral fissure?
opening between upper & lower eyelids
What are cilia (pf the eye)?
eyelashes
What are supercilia?
eyebrows
What is a canthus?
junction of superior & inferior palpebrae; edges of palpebral fissure
What is the lacrimal caruncle?
fleshy prominence at medial canthus; includes sweat & sebaceous glands
What is the lateral corner of the eye?
lateral or temporal canthus
What is the medial corner of the eye?
medial of nasal canthus
What is the lacrimal puncta?
pin-hole opening in lacrimal papilla; permits draining of lacrimal fluid from cornea
What are tarsal plates?
sheets of dense fibrous CT deep to skin and muscle of eyelids
What are the glands in the tarsal plates?
Tarsal glands = Meibomian glands
What are Meibomian glands?
modified sebaceous glands in the tarsal plates of the eyes
What are the functions of the secretion from Meibomian glands?
lubricate margins of eyelids, help increase surface tension to help lacrimal fluid stay on cornea
What glands are found in the eyelids?
Meibomian & ciliary (Moll & Zeis)
What are the ciliary glands?
glands of Moll, glands of Zeis
What are the glands of Moll?
small modified sweat glands on the eyelids
What are the glands of Zeis?
small modified sebaceous glands on the eyelids
What is a sty?
infected ciliary gland of eyelid
What is a hordeolum?
same as sty
What is a chalazion?
plugged meibomian gland, cyst-like
What is the conjunctiva?
mucous membrane covering inner eyelids and sclera
What are the 2 parts of the conjunctiva?
palpebral (lining inner eyelid) & bulbar (reflects onto eyeball?
What other eye structure is continuous with the conjunctiva?
bulbar conjunctiva becomes continuous with outer cornea
What are conjunctiva fornices?
spaces between eyelid & cornea where palpebral conjunctiva meets bulbar conjunctiva
What gland is in the superior lateral anterior portion of the orbit?
lacrimal gland
What are the functions of lacrimation?
moistens, cleans, lubricates, protects cornea
What kind of nerve provides secretomotor innervation to the lacrimal gland?
parasympathetic
What kind of nerve provides vasomotor innervation to the lacrimal gland?
sympathetic
What is the preganglionic nerve for parasympathetic innervation of the lacrimal gland?
greater petrosal n. (CN VII)
Where are the postganglionic neuron cell bodies for parasympathetic innervation of the lacrimal gland?
sphenopalatine ganglion
Where are the postganglionic neuron cell bodies for sympathetic innervation of the lacrimal gland?
superior cervical ganglion of sympathetic chain
What kind of innervation do parasympathetic fibers provide to the lacrimal gland?
secretomotor
What kind of innervation do sympathetic fibers provide to the lacrimal gland?
vasomotor
What path does lacrimal fluid follow after secretion by the lacrimal gland?
lacrimal gland ducts -> eyeball surface -> lacrimal puncta (at papillae) -> lacrimal canaliculi -> nasolacrimal duct -> inferior meatus of nasal cavity
What causes circulation of lacrimal fluid?
blinking & eye movement
Does lacrimal fluid flow medially or laterally?
medially
What is innervated by the greater petrosal n.?
lacrimal glands
What happens to cranial dura at the orbit?
separates into periorbita & orbital dura
What is periorbita?
continuation of periosteal layer of cranial dura; encapsulates all orbital structures; easily separable from orbital bones
What is orbital dura?
continuation of meningeal layer of cranial dura surrounding CN II
Which layer of cranial dura form periorbita?
periosteal
Which layer of cranial dura forms orbital dura?
meningeal
What fascial structure is formed by the periosteal layer of cranial dura entering the orbita?
periorbita
What fascial structure is formed by the meningeal layer of cranial dura entering the orbit?
orbital dura
What surrounds the optic n. in the orbit?
orbital dura
What eyeball structure is continuous with orbital dura?
sclera
What fascial layer is continuous with the sclera?
orbial dura
What provides packing structure in the orbit?
large amounts of adipose
What is Tenons Capsule?
smooth, thin, membranous layer of fascia on the anterior edge of orbital fat; posterior to eyeball
What is fascia bulbi?
same as Tenons Capsule
What is the episcleral space?
potential space between the sclera and the tenons capsule
What forms the socket for the eyeball?
orbital fat, tenons capsule, episcleral space
What are the 7 extraocular muscles?
4 rectus (lat, med, sup, inf), 2 obliques (sup, inf), levator palpebra superioris
What is the common origin for the 4 rectus muscles of the eye?
annulus tendineous
What is annulus tendineous?
ring-like tendon at apex of orbit; common origin of rectus muscles
Where does the lateral rectus m. insert?
lateral sclera
Where does the medial rectus m. insert?
medial sclera
Where does the inferior rectus m. insert?
inferior sclera (ant/med to vertical axis)
Where does the superior rectus m. insert?
superior sclera (ant/med to vertical axis)
Where does the inferior oblique m. originate?
anteromedial orbital floor
Where does the superior oblique m. originate?
body of sphenoid above annulus tendineous
Where does the inferior oblique m. insert?
lateral posterior eyeball
Where does the superior oblique m. insert?
superior lateral eyeball (posterior to vertical axis)
What is the action of the lateral rectus m.?
abduction of eyeball
What is the action of the medial rectus m.?
adduction of eyeball
What is the action of the superior rectus m.?
elevation w/ adduction and intorsion (MR)
What is the action of the inferior rectus m.?
depression w/ adduction and extorsion (LR)
What is the action of the inferior oblique m.?
elevation w/ abduction and extorsion (LR)
What is the action of the superior oblique m.?
depression w/ abduction and intorsion (MR)
What innervates the lateral rectus m.?
CN VI - abducens
What innervates the medial rectus m.?
CN III - oculomotor
What innervates the superior rectus m.?
CN III - oculomotor
What innervates the inferior rectus m.?
CN III - oculomotor
What innervates the superior oblique m.?
CN IV - trochlear
What innervates the inferior oblique m.?
CN III - oculomotor
What is the common tendon of Zinn?
annulus tendineous
What is the trochlea of the eye?
fibrocartilaginous loop or sling of tissue on anterosuperomedial orbit; superior oblique tendon passes through it
Which extraocular muscles have relatively pure movements?
medial and lateral recti mm.
What 2 movements keep the eyes coordinated?
conjugate/parallel movements & vergence movements
When do the eyes use parallel movements?
tracking a moving object; tracking stationary object while moving
When do the eyes use vergence movements?
changing distance of focus; converging or diverging
Where does the levator palpebra superioris m. originate?
orbital apex
Where does the levator palpebra superioris m. insert?
superior tarsal plate/ superior palpebrum
What is a symptom of paralysis of levator palpebra superioris?
ptosis - upper eyelid droops
What is a cause of ptosis?
paraylsis of levator palpebra superioris m.
Which muscles are considered accessory muscles in the orbit?
tarsal mm.
What muscle type are the tarsal mm.?
smooth muscle
What innervates the tarsal mm.?
postganglionic sympathetic fibers
What muscles open both eyelids?
tarsal mm.
What is a cause of narrowed palpebral fissure?
paralysis of tarsal mm. - sympathetic damage in head
What is the major artery of the orbit?
opthalmic a.
What are the 8 branches of the opthalmic a.?
central, lacrimal, ant & post ciliary, supraorbital, ant & post ethmoidal, supratrochlear
Where is & what is supplied by the central a.?
inside optic n. - inner layers of retina?
Where is & what is supplied by the lacrimal a.?
lateral orbit - lacrimal gland, lateral eyelids, some skin of lateral orbit
Where is & what is supplied by the posterior ciliary a.?
branches of the lacrimal & opthalmic aa. - goes to posterior choroid capillaries of eyeball
Where is & what is supplied by the anterior ciliary a.?
branches of the lacrimal & opthalmic aa. - goes to anterior choroid capillaries of eyeball
Where is & what is supplied by the supraorbital a.?
thru supraorbital notch/foramen - to superior orbit, skin of forehead and upper eyelid
Where is & what is supplied by the supratrochlear a.?
terminal branch of opthalmic a. - to top bridge of nose & medial forehead
Where is & what is supplied by the ethmoidal aa.?
thru ethmoidal foramina - to ethmoid air cells, frontal sinuses, part of nasal cavity
Which arteries supply the eyeball wall and retina?
central a., ant & post ciliary aa.
Which arteries supply inner layers of retina?
central aa.
Which arteries supply lacrimal gland?
lacrimal a.
Which arteries supply lateral orbit & eyelids?
lacrimal a.
Which arteries supply choroid capillaries of eyeball?
ant & post ciliary aa.
Which arteries supply superior orbit?
supraorbital a.
Which arteries supply skin of forehead & upper eyelid?
supraorbital a.
Which arteries supply medial forehead soft tissues?
supratrochlear a.
What arteries supply the top bridge of nose?
supratrochlear a.
Which arteries supply the ethmoid air cells?
ethmoidal aa.
Which arteries supply frontal sinuses?
ethmoidal aa.
Which arteries supply part of the nasal cavity?
ethmoidal aa.
What forms the central a.?
opthalmic a.
What forms the lacrimal a.?
opthalmic a.
What forms the posterior ciliary a.?
opthalmic & lacrimal aa.
What forms the anterior ciliary a,?
opthalmic & lacrimal aa.
What forms the supraorbital a.?
opthalmic a.
What forms the supratrochlear a.?
opthalmic a.
What forms the ethmoidal aa.?
opthalmic a.
What 4 major veins drain the orbit?
superior & inferior opthalmic, central, and vortex vv.
Where does the superior opthalmic v. drain to?
cavernous sinus
Where does the inferior opthalmic v. drain to?
cavernous sinus or superior opthalmic vv.
Where does the central v. drain to?
opthalmic vv. (or cavernous sinus)
Where do the vortex vv. drain to?
opthalmic vv. (into cavernous sinus)
What does the superior opthalmic v. drain?
orbital elements (via supraorbital vv. - forehead, etc)
What does the inferior opthalmic v. drain?
inferior orbital elements
What does the central v. drain?
inner retinal v.
What do the vortex vv. drain?
outer eyeball; choroid capillary plexus
What vein is inside the optic nerve bundle?
central v.
What vein is surrounding the optic nerve bundle?
vortex vv.
What cranial nerve creates the opthalmic n.?
trigeminal (V1)
What kind of information is carried by the opthalmic n.?
sensory only
Where does the opthalmic n. exit the skull?
superior orbital fissure
Where are the cell bodies for opthalmic n. neurons?
trigeminal ganglion
What are the 3 branches of the opthalmic n.?
frontal, lacrimal, nasociliary nn.
What’s the largest branch of the opthalmic n.?
frontal n.
What branch of the opthalmic n. heads laterally?
lacrimal n.
What branch of the opthalmic n. haeds medially?
nasociliary n.
Which branch of the opthalmic n. heads superiorly?
frontal n.
What are the branches of the frontal n.?
supraorbital, supratrochlear nn.
What are the branches of the nasociliary n.?
long ciliary, ethmoidal, infratrochlear, nasociliary communicating rami
What are the branches of the lacrimal n.?
no named branches
Which branch of the opthalmic n. is smallest?
lacrimal n.
What is innervated by the supraorbital n.?
skin of forehead, parts of upper eyelid, parts of conjunctiva
What is innervated by the supratrochlear n.?
parts of upper eyelid, parts of conjunctiva, skin of medial forehead
What is innervated by the ethmoidal nn.?
mucous membranes of ethmoid air cells, frontal sinus, and part of nasal cavity
What is innervated by the infratrochlear n.?
skin of medial canthus, topmost bridge of nose
What innervates the upper eyelid?
supraorbital & supratrochlear nn.
What innervates the conjunctiva?
lacrimal, supraorbital & supratrochlear nn.
What innervates the skin of the forehead?
supraorbital & supratrochlear nn.
What innervates the mucous membrance of ethmoid air cells?
ethmoidal nn.
What innervates the mucous membrane of frontal sinus?
ethmoidal nn.
What innervates the mucous membrane of part of nasal cavity?
ethmoidal nn.
What innervates the skin at the medial canthus?
infratrochlear n.
What innervates the skin at the topmost bridge of the nose?
infratrochlear n.
What goes through the ciliary ganglion from the opthalmic n.?
communicating rami from nasociliary n.
What hitchhikes on the nasociliary n.?
postganglionic sympathetic fibers from internal carotid nerve plexus to dilator pupillae m.
What innervates the eyeball (sensory)?
long ciliary nn. (from nasociliary n.)
What is innervated by the long ciliary nn.?
eyeball including cornea & iris; fibers into nerve plexus of choroid layer
What is the terminal branch of the nasociliary n.?
infratrochlear n.
What hitchhikes on the lacrimal n.?
postganglionic sympathetic fibers (lacrimal gland vasomotor) & postganglionic parasympathetic fibers from sphenopalatine ganglion (lacrimal gland secretomotor)
What innervates the lacrimal gland (sensory)?
lacrimal n.
What innervates the lateral orbit?
lacrimal n.
What is innervated by the lacrimal n.?
parts of conjunctiva, upper eyelid, superolateral orbit, lacrimal gland
What kind of ganglion is the ciliary ganglion?
parasympathetic
What is innervated by axons from neurons in the ciliary ganglion?
constrictor pupillae & ciliary mm.
What is innervated by short ciliary nn.?
connect ciliary ganglion to back of eye
What innervates contrictor pupillae mm.?
short ciliary nn. (parasymp from ciliary ganglion)
What innervates ciliary mm.?
short ciliary nn. (parasymp from ciliary ganglion)
What is the bulbous oculi?
eyeball
What are the 3 layers of the bulbous oculi?
inner, middle, & outer tunics
What forms the outer tunic of the bulbous oculi?
sclera & cornea
What structures are continuous with the sclera?
orbital dura (around CN II); cornia (at limbus)
What tissue makes up the sclera?
fibrous CT
What makes the posterior part of the outer tunic of the bulbous oculi?
sclera
What are the 3 layers of the cornea?
anterior, middle, inner
What is the function of the cornea?
refractive
Is the outer tunic of the eyeball vascularized?
poorly
What tissue makes up the anterior layer of the cornea?
stratified squamous nonkeratinized epithelium
What tissue makes up the middle layer of the cornea?
connective tissue
What tissue makes up the inner layer of the cornea?
simple squamous epithelium
Which layer makes up most of the cornea?
middle layer
What is the limbus?
where conjunctiva, sclera, cornea meet up
What is the anterior layer of the cornea continuous with?
bulbar conjunctiva
What is another name for the middle tunic?
vascular layer
What structures are in the middle tunic?
choroid, iris, ciliary body
What is the choroid?
posterior part of middle tunic of eyeball
What tissue makes up the choroid?
loose CT
What arteries supply the choroid?
anterior & posterior ciliary aa.
What veins drain the choroid?
vortex vv.
What nerves are found in the choroid?
ciliary nn. carrying sensory from V1 & postganglionic symp and parasymp fibers to eyeball
What tissue makes up the iris?
loose CT covered by epithelium
What’s the most notable feature of the iris?
pigmentation
What is the opening in the iris?
pupil
What is the pupil?
adjustable opening in iris
What muscle increases the size of the pupil?
dilator pupillae m.
What muscles decreases the size of the pupil?
sphincter (constrictor) pupillae m.
Which pupillae muscle has concentric fibers?
sphincter pupillae m.
Which pupillae muscle has radial fibers?
dilator pupillae m.
What innervates the sphincter pupillae m.?
parasymp preganglionic fibers (CN III) -> postganglionic neurons ciliary ganglion
What innervates the dilator pupillae m.?
symp preganglionic fibers (T1) -> postganglionic neurons superior cervical ganglion
What action of the pupil is triggered by the parasympathetic nervous system?
closing (sphincter pupillae m.)
What action of the pupil is triggered by the sympathetic nervous system?
opening (dilator pupillae m.)
What is the cilary body?
circular structure between the choroid and the iris that controls lens tension and secretes aqueous humor
What secretes aqueous humor?
ciliary body
Where is the posterior chamber of the eye?
between iris & lens
Where is the anterior chamber of the eye?
between iris & cornea
Where is aqueous humor resorbed?
sinus venosus sclerae (Canal of Schlemm)
What is the canal of Schlemm?
sinus venosus sclerae
What is the sinus venosus sclerae?
where aqueous humor is resorbed, at angle between iris & cornea
What are the functions of aqueous humor?
refraction; nutrients & fluid to corner & lens; interocular pressure (via circulation dynamics)
What is glaucoma?
condition of interference of circulation dynamic of aqueous humor; usually increase in interocular pressure
What holds the lens in place?
suspensary ligaments
What are suspensary ligaments?
ligaments from peripheral margin of lens to ciliary body
What are zonular ligaments?
suspenary ligaments
What controls circumferential tension on the lens?
suspensary ligaments
What effect is created by the increased tension of suspensary ligaments?
lens has smaller A-P diameter & less convexity
What effect is created by decreased tension of suspensary ligaments?
lens had larger A-P diameter & more convexity
What tenses the suspensary ligaments?
ciliary mm.
What are the ciliary mm.?
smooth muscle in ciliary bodies for changing shape of lens
What is lens accommodation?
reflexive action refocusing eyes when gaze shifts from far to near; contracting ciliary mm.
What action of ciliary mm. tenses the suspensary ligaments?
ciliary mm. relaxing
What action of the ciliary mm. relaxes the suspensary ligaments?
ciliary mm. contracting
What action of ciliary mm. increases lens A-P dimension?
ciliary mm. contracting
What action of the ciliary mm. decreases lens A-P dimension?
ciliary mm. relaxing
What action of the ciliary mm. is better for close focus?
ciliary mm. contracting
What action of ciliary mm. is better for distant focus?
ciliary mm. relaxing
What innervates the ciliary mm.?
preganglionic parasymp fibers (CN III) -> postganglionic parasymp neurons ciliary ganglion
What part of the autonomic nervous system triggers the ciliary mm.?
parasympathetic
How does the height of the ciliary body change then ciliary mm. contract?
ciliary m. contraction makes ciliary bodies taller
What occupies the inner layer of the bulbous oculi?
the retina
What is the retina?
inner surface of eyeball; sight sensation
What are the 2 layers of the retina?
pigmented & neural layers
Which layer of the retina does light hit first?
neural layer
What are the functions of the pigmented layer of the retina?
absorb light, structural & nutritional support
What gives color to the pigmented layer of the retina?
melanin
What tissue makes up the pigmented layer of the retina?
simple cuboidal
What are the photoreceptive cells of the eye?
rods and cones
What is the function of cone cells?
color vision, high resolution, central vision
What is the function of rod cells?
peripheral vision, low resolution, low-light vision
What are bipolar cells?
the innervate rods & cones
What are ganglion cells?
innervate bipolar cells
What is the ora serrata?
anterior margin of retina at ciliary body
What artieries supply the reinta?
central & ciliary aa.
What drains the retina?
retinal vv. -> central vv. -> cavernous sinus (opthalmic vv.)
Which photoreceptive cell handles color vision?
cones
Which prohotreceptive cell handles high resolution?
cones
Which photoreceptive cell handles central vision?
cones
Which photoreceptive cell handles peripheral vision?
rods
Which photoreceptive cell handles low-light vision?
rods
What innervates the rods & cones?
bipolar cells
What innervates the bipolar cells?
ganglion cells
What is the anterior margin of the retina?
ora serrata
What is formed by the axons of ganglion cells?
optic n. (CN II)
Where does the optic nerve leave the retina?
optic disc
What is the effect on vision from the optic disc?
“blind spot” because no room for rods & cones here
What is papillederma?
swelling of optic disc, compromising vision
What is vitreous body?
transparent hydrophilic gel within eyeball
What is vitreous humor?
the fluid hydrating the gel vitreous body
What’s the function of the vitreous body?
holds structures in place; fill 4/5 volume of eyeball; refractive medium
What is the hyaloid canal?
extends from the optic disc to lens thru vitreous; marks position of embryonic hyaloid a. to embryonic lens
What embryonic remnant can sometimes be found in the eye?
hyaloid canal
What refracts the light entering the eye?
vitreous body, lens, aqueous humor, cornea
What provides general sensory innervation to the eyeball?
V1, especially nasociliary n. (long & short ciliary nn.)
What nerve carries preganglionic parasymp neurons to the eyeball?
CN III
What eye msucles are innervated parasympathetically?
constrictor pupillae m., ciliary mm.
What eye muscles are innervated sympathetically?
dilator pupillae m., vasomotor to vessels of eyeball
Where is the infratemporal fossa?
deep to the mandible, below temporal fossa & zygomatic arch
What forms the anterior border of the infratemporal fossa?
posterior maxilla
What forms the medial border of the infratemporal fossa?
sphenoid (lateral pterygoid plate)
What forms the superior border of the infratemporal fossa?
sphenoid (greater wing)
What forms the lateral border of the infratemporal fossa?
mandible
What 4 other areas of the skull are connected to the infratemporal fossa?
temporal fossa, cranial cavity (middle fossa), orbit, sphenopalatine fossa
What passes from the infratemporal fossa to the cranial cavity?
V3 N & middle meningeal A
What passes from the infratemporal fossa to the orbit?
infraorbital N,A,V
