What cells form the optic nerve?

The optic nerve (ON) is constituted by the axons of the retinal ganglion cells (RGCs). These axons are distributed in an organized pattern from the soma of the RGC to the lateral geniculated nucleus (where most of the neurons synapse).

What is the optic nerve made of?

retinal ganglion cells
The optic nerve is mainly made up of the axons (nerve fibers) of the retinal ganglion cells from the retina. The optic disc or nerve head is the point where the axons from the retinal ganglion cells leave the eye.

What forms the optic nerve in the eye?

The optic nerve begins at the optic disk, a structure that is 1.5 mm (0.06 inch) in diameter and is located at the back of the eye. The optic disk forms from the convergence of ganglion cell output fibres (called axons) as they pass out of the eye.

Do ganglion cells form the optic nerve?

Ganglion cells are the major output cells of the retina. Their axons gather at the optic disk, where they become myelinated and form the optic nerve.

What cells are in the optic disc?

About 3 mm. to the nasal side of the macula lutæ is the entrance of the optic nerve (optic disk), the circumference of which is slightly raised to form an eminence (colliculus nervi optici). The optic disc (optic nerve head) is the location where ganglion cell axons exit the eye to form the optic nerve.

Is the optic nerve anterior or posterior?

The optic nerve has four major portions: intraocular, intraorbital, intracanalicular, and intracranial. Posterior to the lamina cribrosa, optic nerve axons are myelinated by oligodendrocytes similar to those in white matter tracts in the brain and spinal cord.

What does the macula do?

A macular hole is a small break in the macula, located in the center of the eye’s light-sensitive tissue called the retina. The macula provides the sharp, central vision we need for reading, driving, and seeing fine detail.

What do Rod cells detect?

Rod cells are stimulated by light over a wide range of intensities and are responsible for perceiving the size, shape, and brightness of visual images. They do not perceive colour and fine detail, tasks performed by the other major type of light-sensitive cell, the cone.

What is the function of macula?

The macula is part of the retina at the back of the eye. It is only about 5mm across but is responsible for our central vision, most of our colour vision and the fine detail of what we see. The macula has a very high concentration of photoreceptor cells – the cells that detect light.

What do ganglion cells do in the eye?

Retinal ganglion cells process visual information that begins as light entering the eye and transmit it to the brain via their axons, which are long fibers that make up the optic nerve. There are over a million retinal ganglion cells in the human retina, and they allow you to see as they send the image to your brain.

What neurotransmitter do ganglion cells release?

Glutamate is also considered to be the neurotransmitter of all bipolar cells and most ganglion cells in the vertebrate retina including the monkey retina (Kalloniatis and Marc, personal communication and Marc et.

Is the macula medial or lateral to optic disc?

Lateral to the optic disc is a small oval area called the macula, or central retina. It contains specialized photoreceptors known as cone cells which are responsible for the sharpest of vision. At the centre of the macula there is a depression called the fovea centralis.

Where are the glial fibers attached to the optic nerve?

In the periphery of the head of the optic nerve, the glial fibers are attached to the elastic membrane and choroid; while in the centre of the optic disc, it has attachments to the perivascular connective tissue. The glial cells are densely packed and flattened in the anteroposterior plane, with numerous capillaries lying around the cell layer.

What are the subdivisions of the optic nerve head?

The optic nerve head can be further subdivided into the surface nerve fiber layer, prelaminar region and lamina cribrosa.

Where is the ganglion cell located in the retina?

Retinal ganglion cell. A retinal ganglion cell (RGC) is a type of neuron located near the inner surface (the ganglion cell layer) of the retina of the eye. It receives visual information from photoreceptors via two intermediate neuron types: bipolar cells and retina amacrine cells.

Where is the intracanalicular part of the optic nerve?

Within the optic canal lies the intracanalicular part of the optic nerve. The optic canal is formed within the lesser wing of the sphenoid bone. There is significant variability in the thickness of the walls of the optic canal such that the thickness increases from medial to lateral, and from superior to inferior.