Final answer:
Retinal ganglion cells process light signals and send visual information through axons in the optic nerves along different pathways—magnocellular and parvocellular—for various visual qualities.
Step-by-step explanation:
When retinal ganglion cells receive light signals, it triggers a complex process of visual information transmission. These cells have axons that make up the optic nerves, carrying different types of visual information. The ganglion cell axons can carry information on form, movement, depth, brightness, color, and fine detail.
Certain axons follow the magnocellular pathway, important for form and motion, while others follow the parvocellular pathway, associated with color and detail. Additionally, the visual signals processed by this system also contribute to the control of pupillary size.
In dim light, the sympathetic system causes pupil dilation to allow more light to enter, while in bright conditions, the parasympathetic system induces pupil constriction to reduce light entry.
Moreover, retinal processing involves the integration of signals from cones and rods, via bipolar cells, before reaching the ganglion cells, where a great deal of visual information processing takes place within the retina.
Ultimately, the visual information processed by the ganglion cells is transmitted through several brain structures. The superior colliculi in the midbrain help in coordinating eye movements and integrating auditory information. The suprachiasmatic nucleus (SCN) of the hypothalamus receives input that influences the circadian cycle.
The optic nerves travel through the optic chiasma, allowing the visual information from both eyes to be combined and interpreted correctly by the brain.