The eye and its muscles Flashcards
(39 cards)
what part of the globe of the eye do all the extraocular muscles attach to
the sclera
3 actions of the inferior oblique muscle
elevates
abducts
laterally rotates
3 actions of the superior oblique muscle
depresses
abducts
medially rotates
where does the superior oblique muscle originate
the roof of the sphenoid bone
what is the purpose of the 2 oblique muscles
to counteract rotation created by the recti as the recti dont produce a pure action, since their long axis is not in line with the
what is the main abductor of the eye
lateral rectus, but the obliques help this action
3 actions of the superior oblique muscle
elevates, medially rotates, adduction
what nerve innervates levator palpibrae superioris
oculomotor nerve CN 3
what muscle within the upper eyelid has innervation via the sympathetic system to open the eye lid
superior tarsal muscke
where does the the superior tarsal plate of the upper eyelid originate
the lesser wing of the sphenoid bone
what does the levator palpabrae superioris insert onto
the superior tarsal place
what gland is on a more lateral plane than the latral rectus muscle
the lacrimal gland
what is the conscious innervation of the lacrimal gland
trigeminal nerve, V1
what 2 eye muscles have isolated actions and so are tested first
medial and lateral rectus
what innervates the medial rectus muscle
oculomotor nerve
what position do we put the eye in to test inf and sup oblique
put the eye in a position, using superior and inferior rectus that would give maximum rotation and look for complete correction by the obliques
to test superior obique, what position would you put the eye into
abduct the eye 30 degrees, and look up, so that inferior rectus would be giving maximum lateral rotation
to test inferior oblique, what position would you put the eye in
look medially 30 degrees, then look down. so that superior rectus would be trying to give maximum medial rotation
does inferior oblique stop intorsion or extortion?
intorsion
why do you ask the patient to look 30 degrees laterally to test superior rectus
the pull of the muscles to be parallel to the optic axis
eye problems: what is a duction
this is abduction or adduction of just one eye, so monocular
eye problems: what are versions
bilateral, this is adduction or abduction of both eyes, this is dextroversion as they cannot straighten their eyes
eye problems: what are vergences
this is binocular, but where the eyes aren’t pointing in the same direction, so disconjugate, so both are looking medially
when going down stairs and seeing 2 sets, which muscle should be working. which one is not working and what type of movement is it failing to oppose
inferior rectus and superior oblique.
superior oblique, lateral rotation (extorsion)