Anatomy: Extraocular Muscles Flashcards
Extraocular muscles
Located within the orbit.
Act to control the movement of the eyeball and superior eyelid.
Extraocular muscles responsible for eye movement (6)
Superior rectus inferior rectus medial rectus lateral rectus inferior oblique superior oblique
Responsible for superior eyelid movement (1)
levator palpebrae superioris
levator palpebrae superioris
Only muscle involves in raising superior eyelid.
LPS Attachments
Originates from lesser wing of sphenoid bone, immediately above the optic foramen
Attaches to superior tarsal plate of upper eyelid
LPS Actions
Elevates upper eyelid
LPS innervation
Oculomotor nerve (CN III)
Superior tarsal muscle
Collection of smooth muscle fibres within levator palpebrae superiors
Superior tarsal muscle innervation
sympathetic nervous system
Recti muscles origin
characteristically originate from common tendinous ring.
From origin, muscles pass anteriorly to attach to sclerotic of the eyeball
Common tendinous ring
ring of fibrous tissue, which surrounds the optic canal at the back of the orbit
Superior rectus attachments
Origin: superior part of common tendinous ring
Attaches to superior and anterior aspect of sclera
Superior rectus actions
Elevation
Also contributes to adduction and medial rotation of the eyeball
Superior rectus innervation
Oculomotor (CN III)
Inferior rectus attachments
origin: inferior part of common tendinous ring
Attaches to inferior and anterior aspect of the slur
Inferior rectus actions
depression
also contributes to adduction and lateral rotation of the eyeball
inferior rectus innervation
Oculomotor nerve (CN III)
Medial rectus attachments
Origin: medial part of common tendinous ring
Attaches to anteromedial aspect of sclera
medial rectus actions
Adducts the eyeball
Medial rectus innervation
Oculomotor nerve (CN III)
Lateral rectus attachments
originates from lateral part of common tendinous ring
Attaches to anterolateral aspect of sclera
Lateral rectus actions
abducts the eyeball
Lateral rectus innervation
Abducens nerve (CN VI)
Oblique muscles approach to the eyeball
Angular approach
Attach to posterior surface of sclera
Superior oblique attachments
originates from sphenoid bone
Tendon passes through trochlea and then attaches to sclera of the eye, posterior to superior rectus
superior oblique actions
depresses, abducts and medially rotates the eyeball
Superior oblique innervation
Trochlear nerve (CN IV)
Inferior oblique attachments
Originates from anterior aspect of orbital floor
Attaches to the sclera of the eye, posterior to lateral rectus
Inferior oblique actions
Elevates, abducts and laterally rotates eyeball
Inferior oblique innervation
Oculomotor nerve (CN III)