National League for Nursing (NLN) Science Practice Exam

What transmits nerve impulses from the retina to the brain?

1. Optic nerve

2. Cranial nerve

3. Cardiac nerve

4. Esophagus

The correct answer is: Optic nerve

The optic nerve is the correct answer because it is specifically responsible for transmitting visual information from the retina to the brain. The retina contains photoreceptor cells, which convert light into electrical signals. These signals are then relayed through a series of neurons and ultimately transmitted via the optic nerve to the visual cortex in the brain, where they are processed into images. Regarding the other options, cranial nerves do encompass a broader category of nerves that can carry various sensory and motor functions, including the optic nerve, but they do not specifically refer to the structure that transmits visual impulses alone. The cardiac nerve refers to the nerves associated with heart function and does not play a role in vision. The esophagus is part of the digestive system, involved in transporting food, and has no relation to the transmission of nerve impulses from the retina. Understanding the specific functions of these nerves clarifies why the optic nerve is the focused means of visual signal transmission.