Powerpoint for Panopto self study recordings 2 Flashcards
contents of the bony orbit
Frontal bone Sphenoid Lacrimal Ethmoid Maxillary Zygomatic Optic foramen Superior Orbital fissure Inferior orbital fissure
true or false: the medial and inferior walls of the orbit are particularly strong
false weak
AP length of eyeball
24mm
AP length of orbit
40m
function of the lids
skin on the outside, mucous membrane on the inside (conjunctiva)
what type of glands to eyelashes have?
sebaceous
what are the oily secretory glands for?
tear film
what is conjunctiva?
thin vascular membrane that covers inner surface of the eyelids and loops back over sclera
does the conjunctiva cover the cornea?
no
where is the lacrimal gland situated?
in the orbit laterally
what innervates the lacrimal gland?
facial nerve
where does the lacrimal gland open into?
conjunctival sac
what are the events of tears?
During each blink, eyelids spread tears evenly on the surface of cornea
Tears drain through punctae on the medial side of each eyelid
Drains into lacrimal sac which sits over the lacrimal bone
Then drains through nasolacrimal duct into the inferior meatus of the nasal cavity.
function of intrinsic ocular muscles
control pupil diameter & helps alter lens curvature to enable us to see near objects
function of the extrinsic ocular muscles
move the eye.
what are the intrinsic eye muscles?
ciliaris muscle and contrictor pupillae by parasympathetic III
dilator pupillae by sympathetic plexus
what are the extrinsic ocular musclesthat move the eye?
4 Straight muscles called recti Medial rectus (MR) Lateral rectus (LR) Inferior rectus (IR) Superior rectus (SR)
2 oblique muscles Superior Oblique (SO) Inferior Oblique (IO)
where does the recti muscles arise from?
the apex of the orbit from an annular fibrous ring
where does the superior oblique muscle arise from?
roof of the orbit posteriorly
where does the inferior oblique muscle arise from?
floor of the orbit anteriorly
what is the levator palpebrae superioris?
situated above the SR, its a muscle running to the upper eyelid to elevate it
where do the recti mucles insert onto the sclera?
anteriorly
where do the obliques insert onto the sclera?
posteriorly
origin of the LPS?
roof of orbit
origin of all recti?
tendinous ring
origin of SO
lesser wing of sphenoid
insertion of SO
sclera posteriorly
origin of IO
medial part of orbit floor
insertion of IO
sclera posteriorly
innervation of trochlea
trochlear IV
innervation of abducts LR
abducent VI
innervatio of everything else in the eye?
oculomotor III
function of optic II nerve?
carries visual impulses from the eyeball. leaves orbit through optic foramen
function of the oculomotor nerve?
supplies all the muscles going to the eye except 2 and also supplies levator muscle of the eyelid
it carries parasympathetic fibres which synapse at the ciliary ganglion in the orbit
function of the abducent nerve VI
suppllies just one muscle- the lateral rectus
function of the trochlear nerve IV
arises from the dorsal part of the midbrain and supplies just one muscle- superior oblique