The intraorbital portion is described as post-laminar. Which option correctly identifies this description?

The intraorbital portion is described as post-laminar. Which option correctly identifies this description?

• A. Intraocular portion
• B. Intraorbital portion
• C. Prelaminar portion
• D. Intracranial portion

Answer: (B)

Lamina cribrosa marks the boundary between tissue in front of the eye and tissue behind it. Any portion behind this boundary is described as post-laminar, which is why the intraorbital segment—the part of the optic nerve that runs through the orbit from the back of the globe to the optic canal—is described as post-laminar. The part in front of the lamina cribrosa within the eyeball is the intraocular portion (including prelaminar and laminar regions), while the intracranial portion lies beyond the optic canal in the cranial cavity. So labeling the intraorbital portion as post-laminar fits its position behind the lamina cribrosa as the nerve travels through the orbit.

Lamina cribrosa marks the boundary between tissue in front of the eye and tissue behind it. Any portion behind this boundary is described as post-laminar, which is why the intraorbital segment—the part of the optic nerve that runs through the orbit from the back of the globe to the optic canal—is described as post-laminar. The part in front of the lamina cribrosa within the eyeball is the intraocular portion (including prelaminar and laminar regions), while the intracranial portion lies beyond the optic canal in the cranial cavity. So labeling the intraorbital portion as post-laminar fits its position behind the lamina cribrosa as the nerve travels through the orbit.