lecture 9 - EOM 2 Flashcards
where do you look to see for a muscle weakness ?
you use the position where the muscle is maximally used
dextroversion means ..
right
laevoversion means..
left
in primary position which muscles are innervated?
all muscles are equally innervated
why is primary position not good for detecting a muscle weakness ?
each muscle only works by a small amount, therefore you would be unable to detect subtle weakness and you wouldn’t be ale to detect which muscle is causing the problem
what are the secondary positions?
direct elevation
direct depression
laevoversion
dextroversion
which muscles are maximally used in direct elevation
right & left:
Superior Rectus and inferior oblique
which muscles are maximally used in direct depression
right and left
inferior rectus and superior oblique
which muscle is maximally sed in laevoversion
right medial rectus
and
left lateral rectus
which muscle is maximally used in dextroversion
right lateral rectus
left medial rectus
if esotropic, which muscle is weak?
lateral rectus
if exotropic which muscle is weak?
medial rectus
what are the tertiary positions?
dextroelevation
dextrodepression
laevoelevation
laevodepression
which muscles are used maximally in dextroelevation
right Superior Rectus
left inferior oblique
which muscles are used maximally in dextrodepression
right inferior rectus and left superior oblique
which muscles are used maximally in laevoelevation
left Superior Rectus
right inferior oblique
which muscles are used maximally in laevodepression
right superior oblique and left inferior rectus
what is an agonist
the muscle that starts off a movement
what is an antagonist
EOM who’s action opposes the contracting muscles
contraction of the agonist produces …. in the antagonist
relaxation
what is sherringtons law
Whenever an agonist receives an impulse to contract, an equivalent inhibitory input is sent to its antagonist, which relaxes and actually lengthens.
what do the MR and LR do on direction elevation/depression
move out of their plane of action
may contribute
or effect horizontal position by increasing abduction or adduction as the eye elevates or depresses
if you tilt your head to your right shoulder what does the right eye do?
introits and slightly elevates
what are the synergists in RE if you tilt your head to the right
RSR and RSO
what are the direct antagonists in RE if you tilt your head to the right
RIR and RIO
if you tilt your head to your right shoulder what does the left eye do?
extorts and slightly depresses
what are the synergists in LE if you tilt your head to the right?
LIR and LIO
what are the direct antagonists in LE if you tilt your head to the right ?
LSR and LSO
if you tilt your head to your left shoulder what does the left eye do?
intorts and slightly elevates
what are the synergists in LE if you tilt your head to the left
LSR and LSO
what are the direct antagonists in LE if you tilt your head to the left
LIR & LIO
what are the direct antagonists in RE if you tilt your head to the left ?
RSR & RSO
what are the synergists in RE if you tilt your head to the rleftght?
RIR & RIO
W hat action does the RSR mainly have when you carry out ocular motility on dextroelevation ?
elevation
What action does the RSO mainly have when you carry out ocular motility on laevo depression?
depression
What muscles will contract in the Right eye when you tilt your head to the Left?
Right inferior rectus, right inferior oblique
