Atlas of Human Anatomy by Netter

Intrinsic (intraocular) muscles
Ciliary muscle
Constrictor pupillae of iris
Dilator pupillae of iris
Extrinsic (extraocular) muscles
Six muscles
Four arise from common tendineus ring surrounding optic canal and part of superior orbital fissure
Lateral and medial rectus (2)
a. Lie in same horizontal plane
b. Rotate eyeball laterally and medially, respectively
Superior and inferior rectus (2)
a. Lie in same vertical plane
b. Pull eyeball superiorly and inferiorly, respectively
Inferior oblique
a. Works with superior rectus
b. Pulls eyeball superiorly and laterally
Superior oblique
a. Works with inferior rectus
b. Pulls eyeball inferiorly and laterally
Sheathed by reflection of fascial sheath around eyeball (Tenon's capsule)
Medial and lateral check ligaments
a. Triangular expansions of sheath of medial and lateral rectus muscles
b. Attached to lacrimal and zygomatic bones
c. Limit abduction and adduction
Suspensory ligament
a. Union of check ligaments with fascia of inferior rectus and inferior oblique muscles
b. Forms sling that supports eyeball

Muscle Origin Insertion Action Nerve Supply Blood Supply

Extrinsic

muscles of

the eyeball

Superior

rectus

Common tendinous ring Superior aspect of eyeball,

posterior to the corneoscleral

junction

Elevates,

adducts, and

medially rotates

eyeball

Oculomotor nerve

(CN III) -superior

division

Ophthalmic

artery

Inferior

rectus

Common tendinous ring Inferior aspect of eyeball,

posterior to corneoscleral

junction

Depresses,

adducts, and

laterally rotates

eyeball

Oculomotor nerve

(CN III) -superior

division

Ophthalmic

artery

Medial

rectus

Common tendinous ring Medial aspect of eyeball,

posterior to corneoscleral

junction

Adducts eyeball Oculomotor nerve

(CN III) -superior

division

Ophthalmic

artery

Lateral

rectus

Common tendinous ring Lateral aspect of eyeball,

posterior to corneoscleral

junction

Abducts eyeball Abducent nerve (CN

VI)

Ophthalmic

artery

Superior

oblique

Body of sphenoid, above

optic foramen and medial

origin of superior rectus

Passes through trochlea and

attaches to superior sclera

between superior and lateral recti

Abducts,

depresses, and

medially rotates

eyeball

Trochlear nerve

(CN IV)

Ophthalmic

artery

Inferior

oblique

Anterior floor of orbit lateral

to nasolacrimal canal

Lateral sclera deep to lateral

rectus

Abducts, elevates,

and laterally

rotates eyeball

Oculomotor nerve

(CN III) -inferior

division

Ophthalmic

artery

Muscles of

eyelids

Levator

palpebrae

superioris

Lesser wing of sphenoid,

anterior to optic canal

Superior tarsal plate Raises upper

eyelid

Oculomotor nerve

(CN III) -superior

division

Ophthalmic

artery

Orbicularis

oculi

Medial orbital margin,

palpebral ligament, and

lacrimal bone

Skin around orbit palpebral

ligament, upper and lower

eyelids

Closes eyelids Facial nerve (CN

VII)

Facial and

superficial

temporal

arteries

Intrinsic

muscles of

the eye

Sphincter

pupillae

(iris)

Circular smooth muscle of

the iris that passes around

pupil

Constricts pupil Parasympathetic

fibers via

occulomotor (CN III)

Ophthalmic

artery

Dilator

pupillae

(iris)

Ciliary body Dilates pupil Sympathetic fibers

via long ciliary

nerves (CN V 1 )

Ophthalmic

artery

Ciliary

muscles

Corneoscleral junction Ciliary body Controls lens

shape

(accommodation)

Parasympathetic

fibers via short

ciliary nerves (CN

V 1 )

Ophthalmic

artery