Anatomy Flashcards
what bones are involved in bony orbit
frontal bone orbital plate, zygoma, maxillary, lacrimal, ethmoid orbital plate, sphenoid
what bone forms the roof of bony orbit
frontal bone orbital plate
what bone forms the lateral wall of bony orbit
zygoma
what bone forms the floor of bony orbit
maxillary
what bones form the medial wall of bony orbit
lacrimal and ethmoid orbital plate
what bone forms the posterior wall of bony orbit
sphenoid
what bony feature is present in the frontal bone
supraorbital notch
what bony feature is present in the maxilla
infraorbital foramen
where is the superior orbital fissure
greater wing of sphenoid
where is the inferior orbital fissure
sphenoid bone and maxilla
where is the optic canal
lesser wing of sphenoid
what muscle is responsible for closing the eye
orbicularis oculi
what is the orbital septum
sheet of fascia in eyelids
what is the function of the tarsal/Meibomian glands
secrete lipids
where are the tarsal/Meibomian glands
inside tarsal plate in eyelid
what are the names of the two palpebral ligaments of the eyelid
medial and lateral palpebral ligaments
what are the superior and inferior tarsus
dense connective tissue in eyelid that provide structure
what are the two parts of the conjunctiva
palpebral conjunctiva inside eyelids
bulbar conjunctiva on eye
what structures can be seen from looking at the eye
pupil, iris, limbus, sclera, conjunctiva, conjunctival vessels, fornix, caruncle, inferior lacrimal papilla
what is the fornix
where the bulbar and palpebral conjunctiva meet
what is the limbus
junction of cornea and sclera
what is the caruncle
red bit medially on eye
what nerve is responsible for lacrimation
CNVII facial nerve
what is the direction of lacrimal fluid drainage
puncta > canaliculi > lacrimal sac > nasolacrimal duct > inferior meatus
what are names of the segments of the eye
anterior and posterior
what are the names of the chambers of the eye
anterior, posterior and vitreous
where is the anterior chamber
cornea to iris
where is the posterior chamber
iris to suspensory ligament
what type of humour is present in each segment of the eye
anterior: aqueous
posterior: vitreous
where is the posterior segment
behind the lens
what are the names of the 3 layers of the eye
fibrous, vascular, retina
what is the blood supply to the cornea
avascular
what is the fibrous layer of the eye formed of
sclera and cornea
what is the thickest layer of the cornea
stroma
what is the innermost layer of the cornea
endothelium
what is the outer layer of the cornea
columnar epithelium
what is the function of the suspensory ligament
connects the lens to the ciliary body via zonules
how to tell left or right eye on fundoscopy
optic disc always nasal
what is the vascular layer of composed of
uvea
what is uvea
iris, ciliary body and choroid
what are the muscles or the iris and what direction are their fibres
inner circular sphincter pupillae and outer radial dilator pupillae
what is the ciliary body formed of
smooth muscle and blood vessels
what structure secrete aqueous
ciliary body
what is the function of the ciliary body
controls iris/lens shape
what structures are within the optic disc
optic nerve head, central retinal artery, central retinal vein
where is the highest concentration of cones
in the fovea in the macula
what are the two types of photoreceptors
rods and cones
what is the function of choroid
proves nutrition to the peripheral part of the retina
what causes the blind spot
no photoreceptors in the optic disc
where is the blind spot
15 degrees temporally
what is the function of aqueous humour in the posterior chmaber
nourishes avascular lens
what is the function of aqueous humour in the anterior chamber
nourishes avascular cornea
where is aqueous humour reabsorbed
canal of schlemm on sclera at iridocorneal angle
where is aqueous humour reabsorbed to
venous sinus
what artery gives rise to the ophthalmic artery
internal carotid
what artery gives rise to the central retinal artery
ophthalmic artery
what area does the central retinal artery supply
inner 2/3 of the retina
what is the clinical significance of the central retinal artery
end artery
what artery supplies the optic nerve head
posterior ciliary arteries
what are the two main veins responsible for the venous drainage of the eye
central retinal vein and facial vein
what does the central retinal vein drain to
ophthalmic vein
what does the ophthalmic vein drain to
cavernous sinus
where do the rectus muscles originate
common tendinous ring
where to the rectus muscles insert
onto the sclera
which muscle is responsible for lifting the eyelid
levator palpebrae superioris
what structure does the superior oblique pass through
trochlea
where do the superior and inferior oblique muscles insert
onto the sclera
what movement is the medial rectus responsible for
adduction
what movement is the lateral rectus responsible for
abduction
what movement is the inferior rectus responsible for
outwards and downwards (abduction/depression)
what movement is the superior rectus responsible for
outwards and upwards (abduction/elevation)
what movement is the superior oblique responsible for
inwards and downwards (adduction/depression)
what movement is the inferior oblique responsible for
inwards and upwards (adduction/elevation)
what nerve supplies the medial rectus
CNIII oculomotor
what nerve supplies the lateral rectus
CNVI abducens
what nerve supplies the inferior rectus
CNIII oculomotor
what nerve supplies the superior rectus
CNIII oculomotor
what nerve supplies the superior oblique
CNIV trochlear
what nerve supplies the inferior oblique
CNIII oculomotor
what muscle is responsible for the sensory innervation to the face
CNV trigeminal
name the divisions of the trigeminal nerve
V1 ophthalmic, V2 maxillary, V3 mandibular
what is the other name for the blink reflex
corneal reflex
what is the function of the blink/corneal reflex
flush tears of the eye to hydrate the cornea
what is an afferent nerve
towards the CNS
what is the afferent nerve in the blink/corneal reflex
CNV1
what is the efferent nerve in the blink/corneal refllex and what does it supply
CNVII to orbicularis oculi
which origin of the pupillae sphincter is fixed
outer
what is the pupillary light reflex
pupil constricting in response to light
what are the sympathetic and parasympathetic effects of the pupillary light reflex
sympathetic constricts, parasympathetic dilates
what are the consensual and stimulated eyes in the pupillary light reflex
stimulated eye; direct response
consensual eye; non-stimulated
what level to sympathetic axons leave the spinal cord
T1 - L2
what to sympathetic axons do after leaving the spinal cord at the T1-L2 spinal nerves
travel to sympathetic chains running vertical column length
what does sympathetic axons do after ascending/descending sympathetic chains
pass into the anterior / posterior rami of all spinal nerves
what level do sympathetic trunk cervical ganglia leave the spinal cord
T1
what effect does the sympathetic nervous system have on the LPS
constricts in fight/flight for max eyelid elevation
what vessel do sympathetic trunk cervical ganglia follow after synapsing
carotid nerve on carotid artery
what are the parasympathetic cranial nerves
CN III, VII, IX, X
what do parasympathetic nerves supply
internal organs not body wall
where does CN III attach to the CNS
midline/pons
what structure does CN III pass through to supply the LPS, SR, MR, IR and IO extraocular muscles
superior orbital fissure
what structures do the ciliary nerves supply
ciliary body and sphincter pupillae
what input is required for near vision
parasympathetic
what input is required for far vision
parasympathetics stop firing
for near vision what happens to the ciliary muscle, zonule and suspensory ligament
ciliary muscle contracts, zonule relaxes, suspensory ligament relaxes
for far vision what happens to the ciliary muscle, zonule and suspensory ligament
ciliary muscle relaxes, zonule contracts, suspensory ligament contracts
what happens to the lens for near vision
fatter
what happens to the lens for far vision
flattens
what is the accomodation reflex
lens focusing in near vision
what nerve is involved in the accomodation reflex
CN III
what are the 3 types of tear stimulus
basal, reflex and emotional
what is the afferent nerve in reflex lacrimation
CN V1
what is the efferent nerve in reflex lacrimation
CNVII
what antimicrobial property is present in tears
lysozyme
what colour is healthy CSF
clear
what structures are always effected by a change in intracranial pressure
brain or blood or CSF
what are the layers of the meninges from out to in
hard dura, arachnoid, subarachnoid, pia
where is CSF found
in the ventricles and subarachnoid space
what vertebral level does the subarachnoid space end
S2
what vertebral level can you do a lumbar puncture
L3/4 or L4/5
what are the names of the ventricles
right lateral ventricle
left lateral ventricle
3rd ventricle
4th ventricle
what structure connects the 3rd and 4rd ventricles
cerebral aqueduct
what structure secretes CSF
choroid plexus in R/L/3rd ventricles
where is CSF reabsorbed
arachnoid granulations
where does reabsorbed CSF go
dural venous sinuses
