Structure of Eye Orbits:
- Each eye is attached movably with the help of 6 eye muscles in the eye orbit.
- These eye muscles are voluntary & striated.
- There are 4 rectus & 2 oblique eye muscles which are as follows
1.Anterior or external rectus (Lateral Rectus):
- It is attached to the outer lateral side of the eyeball.
- It receives Abducens cranial nerve.
2. Posterior or internal rectus (Medial Rectus):
- It is attached to the inner (medial) side of the eyeball.
- Oculomotor cranial nerve innervates it.
3. Superior rectus:
- It is attached to the mid-dorsal side of the eyeball.
- It receives an oculomotor cranial nerve.
4. Inferior rectus:
- It is attached to the midventral side of the eyeball.
- It receives an oculomotor cranial nerve.
5. Superior oblique muscle:
- It is attached between the external rectus & superior rectus.
- It receives a trochlear cranial nerve.
6. Inferior oblique muscle:
- It is attached between the inferior rectus and external rectus.
- It receives an oculomotor cranial nerve.
Anterior rectus & posterior rectus muscles rotate the eyeball inside & outside. Superior rectus & inferior rectus rotate the eyeballs upside & downside.