Ch 10: Kinematics Flashcards
cardinal direction of gaze
medial rectus
MR
nasal
cardinal direction of gaze
lateral rectus
LR
temporal
cardinal direction of gaze
superior rectus
SR
superior from temporal
cardinal direction of gaze
inferior rectus
IR
inferior from temporal
cardinal direction of gaze
superior oblique
SO
inferior from nasal
cardinal direction of gaze
inferior oblique
IO
superior from nasal
primary and subsidiary actions of
medial rectus
MR
adduction
no subsidiary
primary and subsidiary actions of
lateral rectus
LR
abduction
no subsidiary
primary and subsidiary actions of
superior rectus
SR
primary: supraduction
subsidiary: incycloduction, adduction
primary and subsidiary actions of
inferior rectus
IR
primary: infraduction
subsidiary: excycloduction, adduction
primary and subsidiary actions of
superior oblique
SO
primary: incycloduction
subsidiary: infraduction, abduction
primary and subsidiary actions of
inferior oblique
IO
primary: excycloduction
subsidiary: supraduction, abduction
how many diagnostic positions of gaze are there? how many of these are cardinal?
9 diagnostic positions of gaze
6 are cardinal
what does the ORBIT program stimulate?
a Hess test
according to Hering’s law, how does the Hess test diagnose?
- underaction in the cardinal direction of gaze
- yoke muscle in the other eye shows an overreaction
sherrington’s law states
any signal to an agonist to contract is accompanied by an equivalent inhibition of the antagonist muscle
(only relates to muscles of one eye)
what does Hering’s law state?
that corresponding muscles in the two eyes receive equal excitatory and inhibitory signals
(law relates to binocular eye movements)
what is paresis
a partial immobility of a muscle
what is strabismus
an observable deviation of the lines of sight from the point of regard
the observed deviation of the eyes is called the
primary deviation
when the eye with the paretic muscle attempts to fixate, an excessive excitatory signal is required by the paretic muscle, which is also sent to the corresponding muscle in the normal eye. this leads to a much greater deviation of the two eyes called the
secondary deviation
