A&P Exam 4 (vision)

What are the two photo receptors?

Rods & Cones

What are Cones in charge of?

Bright light, Detailed vision, Sharp images, Color

What are Rods in charge of

Dim light, Peripheral vision, Fuzzy immages, Greyscale

photo pigments

Retinal: molecule in the center of opsin

Opsin: protein shaped like a barbell with retinal in the middle

Rhodopsin: in all rods

Cone Opsins: there are three: red, green, blue

Neural pathway in the retina (in the dark/ depol)

Photoreceptors —> neurotransmitter is released & bipolar cells are inhibited —> cant signal retinal ganglion cells

Neural pathway in the retina (in the light/ not depol/ hyperpolerized)

photoreceptors —> NT will not be released —> inhibition is released, and bipolar cells are on & release NT to the retinal ganglion

Optic Tract vs. Optic Nerve

Tract- central nervous system, Nerve: peripheral nervous system

suprachiasmatic nucleus

sets circadian rhythm

Pretectal nucleus

involved in puplilary responces

Superior Colliculus

involved in visual reflexes

Where do primary visual fibers travel to?

the thalamus

What does the thalamus do?

directs light information into the cerebral cortex

What does the primary visual cortex (occipital lobe) do?

interperates contrast & object orientation (early processing)