Muscles of the Eye Flashcards
What is the difference between extrinsic ocular muscles and the intrinsic ocular muscles?
Extrinsic ocular muscles are on the outside of the eye. Intrinsic muscles are on the inside of the globe.
Define the three positions of the eye.
Primary position - looking straight ahead
Secondary position - looking exactly up and down vertically and exactly horizontally left or right.
Tertiary position - in between secondary position, up and in and down and out.
What is the difference between adduction and abduction?
Adduction is a rotation towards the nose. Abduction is a rotation towards the temple.
Lateral rectus muscle - where is it - what does it do?
The lateral rectus muscle is attached to the outside front of the eye globe and to the back of the annulus of Zinn. The lateral rectus muscle pulls the outside of the front of the globe toward the back of the eye socket.
Medial rectus muscle - where it is - what does it do?
The medial rectus muscle is attached to the inside front of the eye globe and the annulus of Zinn at the back. The medial rectus muscle pulls the inside of the globe toward the back of the eye socket.
Superior rectus muscle - where is it - what does it do?
The superior rectus muscle is attached to the top front of the eye globe and the back of the annulus of Zinn. It pulls the top of the eye back but also towards the nose.
Inferior rectus muscle - where is it - what does it do?
The inferior rectus muscle is attached to the bottom front of the eye globe and at the back of the annulus of Zinn. It pulls the bottom of the eye back and towards the nose.
Superior oblique muscle - where is it - what does it do?
It is attached to the top back of the eye globe on the lateral side, travels across the top of the globe under the superior rectus, goes through the trochlea, and then travels back to attach directly to the bone just above the annulus of Zinn. It pulls the back of the globe toward the nasal side of the eye socket.
Inferior oblique muscle - where is it - what does it do?
The inferior rectus muscle is attached to the back of the eye globe on the lateral side, and attached to the floor of the orbit near the medial side of the front of the eye socket. It pulls the back of the globe towards the nasal side of the eye socket.
Give an example of antagonistic muscles in the eye.
The medial and lateral muscles
What is Shering’s law of equal innervation? Use your own words.
That although your eyes are separate, they work together. The muscles all work together at the same time in a binocular movement.
