Chap 15. RVQs #9 The axons of the ganglion cells form the optic nerve. They exit the eye as the optic disc which is called the blind spot because there are no receptor cells ( rods or cones) there.
Work Step by Step
The rods and cones of the retina synapse with bipolar cells and the bipolar cells connect with the ganglion cells. The axons of the ganglion cells leave the eye and travel to the brain. At the site where the ganglion cell axons exit there are no light receptors ( rods or cones); because no light can be perceived there it is called the blind spot. The axons of the ganglion cells form the optic nerve and then the optic tract., The fibers from each eye divide into two groups , the medial halves decussate ( cross) at the optic chiasm. Some fibers continue to the lateral geniculate nucleus and thence to the visual cortex of the occipital lobe. Other fibers avoid the geniculate nucleus and travel instead to the hypothalamus by way of the pretectal nucleus, and the superior colliculus..