Muscles of the eye

Question 1

How many muscles act on the eye

Answer 1

there are 7 muscles

Levator Palpebrae Superioris
4 recti muscles
2 oblique muscles

Question 2

Levator Palpebrae Superioris

PA
DA
N/S
A

Answer 2

Lesser wing of the sphenoid (anterior and superior to the optical canal

Tarsal plate and skin of the upper eyelid

Oculomotor nerve CN 3
- some deep layers are supplied by sympathetic nerve

Question 3

what are the 4 recti muscles

Answer 3

Superior, Inferior, Medial and Lateral Recti muscles

Question 4

the 4 recti muscles

PA
DA
N/S
A

Answer 4

Common Tendinous Ring - Fibrous cuff surrounding the optical canal and medial part of the SOF

Sclera just posterior to the cornea

Oculomotor nerve, expect for Lateral Rectus which is Abducent nerve (CN6)

• Superior Rectus - Elevates, adducts and medially rotates the eye
• Inferior Rectus - Depresses, adducts and laterally rotates the eye
• Medial Rectus - adducts
• Lateral Rectus abducts

Question 5

Superior Oblique muscle

PA
DA
N/S
A

Answer 5

• Body of the sphenoid
• Sclera, deep to the superior rectus
• Trochlea nerve (CN4)
• Abducts, depresses and medially rotates the eyeball

Question 6

Inferior Oblique muscle

PA
DA
N/S
A

Answer 6

• Anterior part of the floor of the orbit
• Sclera deep to the lateral rectus
• Oculomotor nerve CN3
• Abducts, elevates and laterally rotates the eye