Which of the following explains why there is a blind spot in the eye?

Which of the following helps humans see in the dark?

The amount of light that reaches the retina is controlled by the __________, while the focus is determined by stimulation of the __________.

Which of the following refers to the optic chiasm?

Which of the following does not occur during transmission of a signal from a taste receptor to the brain?

Which of the following structures is not responsible for transmitting information to the acoustic nerve?

The malleus, incus and stapes are components of the __________.

Which of the following is responsible for color vision?

The basal cells of the gustatory system __________.

The optic nerve is formed from the axons of all retinal ganglion cells. The optic nerves from each eye join at the optic chiasm and eventually enter either the left or right optic tract. The optic tract projects to three subcortical areas. One is the lateral geniculate nucleus, which is responsible for processing visual information. One is the pretectal area, which produces pupillary reflexes based on information from the retina. Finally, the superior colliculus uses the information from the retina to generate eye movement.

When light is shone upon one eye, it causes constriction of the pupil in both eyes. Constriction of the eye in which the light is shone is the direct response while constriction of the other is known as the consensual response. The pupillary reflexes are mediated through retinal ganglion neurons that project to the pretectal area which lies anterior to the superior colliculus. The cells in the pretectal area project bilaterally to preganglionic parasympathetic neurons in the Edinger-Westphal nucleus. This is also known as the accessory oculomotor nucleus. The preganglionic parasympathetic neurons in the Edinger-Westphal nucleus send axons through the oculomotor nerve to innervate the ciliary ganglion. The ciliary ganglion's postganglionic neuron innervates the smooth muscle of the pupillary sphincter.

The right optic tract can be described as an __________.