Extrinsic Muscles of the Eye

Question 1

Superior rectus

Answer 1

Origin: Common tendinous ring around Optic N. at back of orbit

Insertion: Top of eyeball

Action: Turns eyeball up

Innervation: Oculomotor N.

Question 2

Inferior rectus

Answer 2

Origin: Common tendinous ring around Optic N. at back of orbit

Insertion: Bottom of eyeball

Action: Turns eyeball down

Innervation: Oculomotor N.

Question 3

Medial rectus

Answer 3

Origin: Common tendinous ring around Optic N. at back of orbit

Insertion: Medial side of eyeball

Action: Turns eyeball in

Innervation: Oculomotor N.

Question 4

Lateral rectus

Answer 4

Origin: Common tendinous ring around Optic N. at back of orbit

Insertion: Lateral side of eyeball

Action: Turns eyeball out

Innervation: Abducens N.

Question 5

Superior oblique

Answer 5

Origin: Common tendinous ring around Optic N. at back of orbit

Insertion: Passes through trochlea, then laterally under superior rectus, and inserts on upper lateral side of eyeball

Action: Turns eyeball down and out

Innervation: Trochlear N.

Question 6

Inferior oblique

Answer 6

Origin: Lower medial anterior corner of orbit

Insertion: Passes laterally under Inferior rectus, and inserts on upper lateral side of eyeball

Action: Turns eyeball up and out

Innervation: Oculomotor N.

Question 7

Levator palpebra superioris

Answer 7

Origin: Posterior roof of orbit

Insertion: Into upper eyelid

Action: Elevates upper eyelid

Innervation: Oculomotor N.