Question

Impulses from photoreceptors are carried to the brain by ________.

• A. Facial nerve
• B. Optic nerve
• C. Auditory nerve
• D. Olfactory nerve

Answer 1

The correct option is B

Optic nerve

The inner layer of the eye is the retina and it contains three layers of cells – from inside to outside – ganglion cells, bipolar cells and photoreceptor cells. There are 2 types of photoreceptors in the retina: rods and cones. Photoreceptor cells contain light-sensitive proteins, photopigments. The rods are most sensitive to light and dark changes, shape and movement and contain only one type of light-sensitive pigment. The photopigments create an impulse when light falls on them. The optic nerve leaves the eye and transmits impulses from the retina to the brain.