Vision: Eye Muscles Flashcards
what do intrinsic muscles control?
pupil diameter and lens curvature
what do extrinsic eye muscles do?
move the eyeball
where do recti eye muscle arise from?
the apex of the eye
where does the superior oblique muscle arise from?
the roof of the orbit posteriorly
where does the inferior oblique muscle arise from?
the floor of the orbit anteriorly
what is the muscle of the eyelid called?
levator palpebrae superioris
where to the recti muscles insert into?
the sclera anteriorly
what does the trochlear nerve supply?
the superior oblique
what does the abducent nerve supply?
the lateral rectus muscle
what does the oculomotor nerve supply?
the levator palpebrae superioris, medial rectus, superior rectus, inferior rectus and inferior oblique
in terms of uniocular eye movement what is looking away from the nose called?
abduction
what is adduction in uniocular eye movement?
the eye looking towards the nose
what is intorsion?
when the top of the eye rotates towards your nose (rotating your head)
what is extorsion?
when the top of your eye rotates away from the nose (rotating your head)
what axis are the eye muscles attached along?
the orbital axis not the optical axis (so muscles will have more than one action on the eyeball)
what is the effect of the oblique’s being inserted to the back of the eyeball?
they pull the posterior part of the eyeball up/down causing the opposite effect on the anterior part. superior oblique depresses the eye. inferior oblique elevates the eyeball.
what the lateral rectus has abducted the eye what is the effect of the superior rectus?
elevation
what the lateral rectus has abducted the eye what is the effect of the inferior rectus?
depression
when will the superior rectus cause intorsion?
when the medial rectus has adducted the eye
when will the inferior rectus cause extorsion?
when the medial rectus has adducted the eye
what is the effect of the superior oblique when the eyeball is adducted?
depression
what is the effect of the superior oblique if the eye is abducted?
intorsion
when will the inferior oblique cause elevation?
when the eyeball is adducted
when will the inferior oblique cause extorsion?
when the eyeball is abducted
where is the ciliaris muscle?
In the ciliary body
where is the constrictor pupillae?
in the iris at the pupillary border
where is the dilator pupillae?
running radially in the iris
what intrinsic eye muscles are innervated by the parasympathetic system?
ciliaris muscle and constrictor pupillae
what intrinsic muscle is innervated by the sympathetic system?
dilator pupillae
