EXTRAOCULAR MUSCLES Flashcards
what are the 7 extra ocular muscles?
superior rectus lateral rectus medial rectus inferior rectus inferior oblique superior oblique levator palpeerde superioris
where does the levator palpebral superioris originate?
lesser wing of sphenoid bone
where does the levator palpebral superioris attach?
superior tarsal plate of upper eyelid
whats the action of levator palpebral superioris?
elevates upper eyelid
what innervates the levator palpebral superioris?
oculomotor nerve
but superior tarsal muscle is innervated by sympathetic nervous system
where do the recti muscles originate?
common tendinous ring
where does the superior rectus muscle attach?
superior and anterior region of sclera
whats the action of the superior rectus muscle?
elevates eyeball
also assists in some adduction and medial rotation
what innervates the superior rectus muscle?
oculomotor nerve
where does the inferior rectus muscle attach?
inferior anterior sclera
what Is the action of inferior rectus?
depression
assists on adduction and lateral rotation
what innervates the inferior rectus muscle?
oculomotor nerve
where does the lateral rectus attach?
anterolateral sclera
whats the action of lateral rectus muscle?
abduction
what innervates the lateral rectus muscle?
abducens nerve cn6
where does the superior oblique muscle originate?
body of sphenoid
where does the superior oblique muscle attach?
sclera of the eye but posterior to superior rectus
whats th action of the superior oblique?
depresses, abducts and medially rotates
what innervates superior oblique?
trochlea nerve cn4
where does the inferior oblique originate?`
anterior aspect of orbital floor
where does the inferior oblique attach?
sclera of the eye posterior to lateral rectus
whats the action of the inferior oblique?
elevates, abducts and laterally rotates
what innervates the infeiror oblique muscle?
oculomotor nerve
what would you see in an oculomotor nerve palsy?
eye down and out
what would you see in a trochlear nerve palsy?
normal eye but diplopia and head tilt
what would you see in an abducens nerve palsy?
adducted eye - due to resting tone of medial rectus
what causes horners syndrome
damage to the sympathetic trunk in the neck - can be caused by Pancoast tumours, thyroid carcinomas etc
how does horners syndrome present?
partial ptosis
anhidrosis on ipsilateral side
miosis
what causes the partial ptosis in horners syndrome?
denervation of the superior tarsal muscle
what causes the miosis in horners syndrome?
denervation of dilator papillae muscle
what causes anhidrosis in horners syndrome?
denervation of sweat glands
