The optic nerve collects stimuli from the retina and exits through the back of the eye to relay the information to the occipital lobe of the cerebrum. The point at which the optic nerve exits the eye contains no photoreceptors (rods and cones), and is unable to interpret light signals. This leads to a blind spot in the eye at the optic disk.

The pigmented part of the eye, called the iris, regulates the amount of light entering the eye. The iris is actually a band of circular muscle capable of regulating the size of the pupil. By dilating or constricting, this ring controls the amount of light that can enter the eye.

The ciliary muscles are responsible for altering the lens shape. When these muscles contract, the lens flattens and the focal length is reduced, allowing focus on objects closer to the eye. While the lens plays an important role in focusing light, it cannot be stimulated directly and relies on action of the ciliary muscles to change its shape.

Rods and cones are the primary photoreceptors in our eyes. The rods are responsible for night vision, allowing us to differentiate different grays and blacks, whereas the cones are responsible for sensing color. Rods are concentrated in the periphery of the retina, making them essential for peripheral vision as well.

The retina contains both rods and cones and is responsible for converting electromagnetic stimulation to electrical impulses. These impulses are fired through the optic nerve to the occipital lobe for processing. The lens helps to focus light on the retina.

The optic nerves cross over in a location known as the optic chiasm, located posterior to the eyes in the brain. The optic tract refers to the portion of the optic nerve that carries signals prior to the optic chiasm, and thus is not involved in the cross. The result of the optic chiasm is that information from the right eye is transmitted to the left visual cortex, while information from the left eye is transmitted to the right visual cortex.

The blind spot created by the optic nerve exiting the eye is known as the optic disc.

The cochlear and vestibular nerves join to form the auditory nerve. The crista are specialized hair cells that help in postural equilibrium and send information via the vestibular nerve. The incus is one of the three auditory bones (the others include the malleus and the stapes), the motion of which is part of sound reception. This information is transmitted via the cochlear nerve. Finally, the cochlea is the fluid-filled structure of the inner ear that translates movement into vibrations (also involved in sound reception). All of the given structures take part in transmitting information to the acoustic nerve.

The malleus, incus, and stapes are the three bones of the ear. Sound enters the external ear by using air as a medium. In the middle ear, vibrations from the air transition to vibrations through bone. The inner ear converts these bone vibrations to fluid vibrations in the cochlea, which converts the fluid vibrations to electrical stimuli for the nervous system.

After taste receptor cells contact solutes in the saliva, action potentials cause a calcium influx through ion channels, which leads to the release of the neurotransmitter that induces an action potential in the afferent nerve. This action potential is carried to the brain for integration and interpretation.

Chloride ions do not enter the receptor during this process.

Rods and cones are the primary photoreceptors in our eyes. The rods are responsible for night vision, allowing us to differentiate different grays and blacks, whereas the cones are responsible for sensing color. There are three main pigments in cones, each perceiving one type of color: red, green, or blue. Deficiency in one type of cone can result in color blindness.

The retina contains both rods and cones and is responsible for converting electromagnetic stimulation to electrical impulses. These impulses are fired through the optic nerve to the occipital lobe for processing. The lens helps to focus light on the retina.

Proprioceptors relay information about the relative position of the body in space. These receptors are embedded in the skin and musculoskeletal system, and are triggered by movement. The prefix "proprio-" means self, making proprioreceptors "receptors of the self."

Barioreceptors detect pressure changes in the blood and are primarily located in the aorta. Photoreceptors include rods and cones, and are responsible for receiving electromagnetic input in the eyes. Thermoreceptors are primarily located in the skin and detect changes in temperature. Somatic sensors are a general category of receptors that carry afferent signals to the brain.

Afferent pathway, containing nerve axons from both eyes. Again, this question requires us to draw on our knowledge of the nervous system, and in particular, the eye. One must remember that the information leading towards the brain is found in the afferent nerves. Information leading away from the central nervous system is found in the efferent nerves. Therefore, answer choices, ‘efferent pathway, containing nerve axons from only one eye’, and ‘efferent pathway, containing nerve axons from both ways’ can be eliminated. Now the question becomes whether the optic tract contains information from one eye or two. The answer is two. Information from the nasal hemiretina (medial half of the retina) of the left eye cross the optic chiasm and enters the right optic tract. The right optic tract is also made up of nerve fibers originating from the temporal hemiretina of the right eye. In that way, the right side of the brain processes information from the left side of the visual world.