45. Orbit Flashcards
Function of suspensory ligaments?
Support eyeball
Function of check ligaments?
Restrict MR and LR
What are the two fluid filled spaces in the eye? Where are they found in relation to the lens?
Aqueous humor - anterior to lens
Vitreous - posterior
Function of aqueous humor?
Maintain intra-occular pressure
Where is the aqueous humor made?
Ciliary body
Where does the aqueous humor drain?
Corneo-scleral junction
Function of vitreous humor?
Support retina
Intraocular muscles? (3)
Dilator pupillae
Sphincter pupillae
Ciliary muscles
Innervation of dilator pupillae?
Sympathetic (carried on blood vessels)
Innervation of sphincter pupillae?
Parasympathetic - CNIII
Function of ciliary muscles?
Change shape of lens for accommodation
Innervation of ciliary muscles?
CNIII
What are the extraoccular muscles? (7)
Levator palpebrae superioris MR LR SR IR SO IO
Which extraoccular muscles attach from the annular ring to the sclera?
SR
IR
MR
LR
Attachment of SO?
Lesser wing of sphenoid
To sclera
Attachment of IO?
Orbital floor
To sclera
In terms of the axis of the eye, how can the eye muscles move the eye in more than one direction?
Axis of orbit (bony cavity) and optical axis (line of gaze) are DIFFERENT
Action levator palpebrae?
Raise upper eyelid
Action SR?
Elevation
Adduction
Intorsion
Action IR?
Depression
Adduction
Extorsion
Action MR?
Adduction
Action LR?
Abduction
Action SO?
Intorsion
Depression
Abduction
Action IO?
Extorsion
Elevation
Abduction
Innervation of extraoccular muscles?
LR6 SO4 AO3
Branches of CN V1?
Lacrimal
Frontal –> supraorbital and supratrochlear
Nasociliary –> ant and post ethmoidal branches
From which artery does the ophthalmic artery branch?
Internal carotid
Arteries and veins of the eye
Slide 27 and 28
Innervation of lacrimal apparatus?
Secretomotor from CNVII (carried in CNV1)
