Last lecture 2 Flashcards
how does the medial rectus move the eye?
moves the eye towards the nose (medially)
how does the lateral rectus move the eye?
moves the eye away from the nose (laterally)
superior rectus moves the eye how?
moves the eye up and laterally
inferior rectus moves the eye how?
moves the eye down and laterally
superior oblique moves the eye how?
rotates eye so top of the eye moves towards the nose, intortion (pupil points down and medially.
inferior oblique moves the eye how?
rotates eye so top of the eye moves away from the nose, extortion pupil points up and medially.
what are the main muscles of the eye?
superior rectus, medial, lateral and inferior rectus
the superior and inferior oblique
describe the wagon wheel test
the patient holds their head still while the practitioner moves a pen in several directions from a start. always returning to the center before changing direction.
informal testing of eye movements is always part of _____ exams.
neurological.
what is known as the “quick and dirty” eye test?
the H shape follow my finger test.
how do you test each muscle individually, bc in the H shape test more than one muscle is acting to produce a specific movement.
the clinician needs to ask them to move their eye into the gaze position
the gaze position is what?
22 degrees laterally from the visual axis. in this position, the six cardinal movements of gaze are tested only a single muscle is tested by moving through the H shape while in a line of gaze.
using the visual axis, each movement is produced by what?
extraoccular muscles ( at least two) working together
initially, the longitudinal axis through the orbit is about? what does this mean
?
22 degrees off the longitudinal axis through the eyeball. ( visual axis)
that means that the contraction of the superior and inferior oblique will move the eyeball not only up but towards the midline (medially)
the actions of lateral and medial recti are simple, the medial recti ____ the eyeball while the lateral rectus ___ the eye
adduct (cross eyed)
abducts (hence the ABducens nerve innervation of lateral rectus)
what would a lesion of CN VI result in?
lesion would result in paralysis of the lateral rectus and the inability to abduct the pupil. the patient would present with an adducted eye due to the unopposed pull of the medial rectus of the affected eye.
superior rectus raises pupil ___ and ___
upward and laterally
inferior rectus pulls pupil ___ and ___
downward and laterally
what is the lateral direction of both the rectus (superior and inferior) due to?
the fact that the sup. and inf. rectus muscles are attached posteriorly and medial to the position of the eyeball in the orbit.
what are the oblique muscles attached to? vs recti muscles?
the posterior half of the globe of each eyeball.
recti muscles are attached to the anterior half of this globe.
when an oblique muscle acts it wants to ____ the eyeball in the orbit
rotate
the superior oblique will pull from the ____ of the eyeball, pulling it?
back, pulling it inferiorly and medially
the inferior oblique will pull from the ____ aspect of the back of the eyeball, pulling it?
inferior aspect, pulling it up and medially.
the primary action of the superior and inferior oblique mm (w/o the visual axis aligned with the line pf pull) is to ?
rotate the eyeball around the visual axis.