Optic nerve

Nervus opticus

Begins at the optic disc where retinal ganglion cell axons converge. It exits the orbit through the optic canal and joins the opposite nerve at the optic chiasm, where nasal fibers cross. The optic tract continues to the lateral geniculate body and visual cortex.

النوع Nerve
جهاز الجسم Nervous
منطقة الجسم Eye
الاسم اللاتيني Nervus opticus
FMA ID 50863

الوظيفة

The second cranial nerve (CN II) that transmits visual information from the retina to the brain. It carries approximately 1.2 million nerve fibers from retinal ganglion cells to the lateral geniculate nucleus and superior colliculus.

الأهمية السريرية

Optic neuritis causes acute vision loss and is associated with multiple sclerosis. Papilledema (optic disc swelling) indicates raised intracranial pressure. Glaucoma causes progressive optic nerve damage. Pituitary tumors can compress the optic chiasm causing bitemporal hemianopia.

الأسئلة الشائعة

What is the optic nerve?
The optic nerve is the second cranial nerve (CN II), formed by the axons of retinal ganglion cells converging at the optic disc. It transmits visual information from the retina to the brain's visual processing centers.
Where is the optic nerve located?
The optic nerve exits the posterior orbit through the optic canal and travels to the optic chiasm, where nasal fibers from each eye cross to the opposite side. The optic tract then continues to the lateral geniculate body and visual cortex.
What is the function of the optic nerve?
The optic nerve carries visual signals—in the form of action potentials from retinal ganglion cells—from the eye to the brain. This pathway enables the brain to process and interpret visual images.
What conditions may be associated with the optic nerve?
The optic nerve may be involved in conditions such as optic neuritis, glaucoma, and compressive lesions at the optic chiasm. Damage at the chiasm may be associated with visual field defects such as bitemporal hemianopia.
What does the optic nerve look like?
The optic nerve appears as a cord-like white structure about 5 cm long, surrounded by meningeal sheaths. On fundoscopy, its origin is visible as the optic disc—a pale, circular region at the back of the eye where retinal fibers converge.

البنى ذات الصلة

accessory nucleus of optic tract nuclei accessorii tractus optici muscle spindle muscle stretch receptor mushroom body corpora pedunculata myelencephalon sulcus limitans cavum septum pellucidum cave of septum pellucidum spinal cord commissure neodentate part of dentate nucleus neodentate portion of dentate nucleus nerve nerves

إخلاء المسؤولية الطبية

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Educational Disclaimer

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.