Orbital cavity and lacrimation Flashcards
Lateral borders of orbital cavity
Zygomatic and sphenoid
Orbital cavity floor
Sphenoid, palatine and maxillary bones
Orbital cavity roof
Frontal bone
Orbital cavity medial border
Sphenoid, ethmoid, lacrimal and maxillary
Difference between orbit of eye and orbit of axis
Orbit is anterolateral but optic axis looks straight ahead
Innervation and function of orbiculares oculi
Facial nerve and closes eyelids
Innervation and function of elevator palpebre superiors
Oculomotor and opens eyelids
Which muscle opens eye
Muller’s muscle
Tarsal’s glands
sebaceous glands posterior to eyelashes - oily secretions limit overflow of tears
Ptosis causes
Ptosis occurs when sympathetic innervation to Muller’s muscle or parasympathetic interruption to levator palpebrae superioris
Lacrimation
facial nerve - greater petrosal nerve - Vidian’s nerve - IOF - orbit - ophthalmic division of trigeminal nerve - makes you cry
Why do you get a runny nose when you cry
Naso-lacrimal duct connected to nasal cavity
LR movement
Abduction
Sr movement
Eye moves medially
SO action
Eye moves down and out
IO contraction
Eye goes up and out
MR action
Adduction
IR action
Down and out
Test SR
Look laterally and up
Test IR
Look laterally and down