• Source: Common tendinous ring

The common tendinous ring, also known as the annulus of Zinn or annular tendon, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the common origin of the four recti muscles of the group of extraocular muscles.
It can be used to divide the regions of the superior orbital fissure.
The arteries surrounding the optic nerve form a vascular structure known as the circle of Zinn-Haller, or sometimes as the circle of Zinn.
The following structures pass through the tendinous ring (superior to inferior):

Superior division of the oculomotor nerve (CNIII)
Nasociliary nerve (branch of ophthalmic nerve)
Inferior division of the oculomotor nerve (CNIII)
Abducens nerve (CNVI)
Optic nerve




Parts


The common tendinous ring spans the superior orbital fissure and can be described as having two parts – an inferior tendon which gives origin to the inferior rectus muscle, and to part of the lateral rectus muscle; and a superior tendon which gives origin to the superior rectus muscle, and to part of the medial and lateral recti muscles.




Eponym


It is named for Johann Gottfried Zinn. It should not be confused with the zonule of Zinn, though it is named after the same person.




References

Kata Kunci Pencarian:

• Common tendinous ring
• Medial rectus muscle
• Lateral rectus muscle
• Inferior rectus muscle
• Extraocular muscles
• Abducens nerve
• Lacrimal nerve
• Eye movement
• Inferior oblique muscle
• Outline of human anatomy