Ch. 10.3 Neural Signals Travel from the Retina to Several Brain Regions Flashcards
What is the optic chiasm?
The point at which the two optic nerves meet
In humans, where do the axons from the retina send their message?
The axons form the half of the retina toward the nose (nasal hemiretina) cross over the opposite side of the brain. The half of the retina toward the temple (the temporal hemiretina) projects its axons to its own side of the brain.
What axons make up the optic nerve (cranial nerve II)?
The ganglion cells in each eye produce action potentials that are conducted along their axons to send visual info to the brain. These axons make up the optic nerve.
What is the optic tract?
The axons of retinal ganglion cells after they have passed the optic chiasm.
What is lateral geniculate nucleus (LGN)?
The part of the thalamus that receives info from the optic tract and sends it to visual areas in the occipital cortex.
What do the axons of neurons in the LGN (lateral geniculate nucleus) form?
The optic radiations. These are the axons from the LGN that terminate in the primary visual areas of the occipital cortex.
Where do the optic radiations end?
in primary visual cortex (V1)
What is the occipital lobe?
Large region of cortex covering much of the posterior part of each cerebral hemisphere, specialized for visual processing.
What are primary visual cortex (V1)?
Also called striate cortex or area 17. The region of the occipital lobe where most of the visual information first arrives in the cortex.
What is the extrastriate?
The surrounding regions of the VI (visual cortex) that are also largely visual in function and work in parallel to process different aspects of visual perception such as form, color, location, and movement.
In what form does the retina project to the brain?
Topographical (maplike)
What is a scotoma?
A region of blindness caused by injury to the visual pathway or brain.
