The Eye

Light in the center of an OFF-center ganglion cell receptive field would: 1) Decrease the number of action potentials 2) Depolarize the bipolar cells signaling the ganglion cells 3) Depolarize the photoreceptors 4) Increase the number of action potentials

1) Decrease the number of action potentials

Retinitis pigmentosa is due to: 1) Degeneration of photoreceptors 2) Increased pressure in the eye 3) Detached retina 4) Eye muscle weakness

1) Degeneration of photoreceptors

The center-surround organization of ganglion cell receptive fields is designed to: 1) Exaggerate border contrast 2) Exaggerate absolute light intensity 3) Accurately represent absolute light intensity 4) Faithfully represent border contrast

1) Exaggerate border contrast

Cells in the retina which fire action potentials: 1) Ganglion cells 2) Bipolar cells 3) Horizontal cells 4) Photoreceptors

1) Ganglion cells

Which of the following statements is FALSE? 1) In mesotopic conditions only rods are used 2) There are approximately 100 million photoreceptors in the eye 3) Cones have few discs 4) Rod photoreceptors have many discs

1) In mesotopic conditions only rods are used

Which of the following is FALSE: 1) M-type ganglion cells are the most common in the retina 2) Red, blue and green cones are defined by the wavelength that produces the maximum response 3) All of the above are TRUE 4) The trichromacy theory states that the brain assigns colors based on the comparison of the responses from the three types of cones

1) M type ganglion cells are the most common in the retina

Which of the following is FALSE? 1) M type ganglion cells have a sustained response to light and small receptive fields 2) OFF-type bipolar cells hyperpolarize in light 3) Horizontal cells are needed for center-surround receptive fields 4) ON-type bipolar cells are sign inverting

1) M type ganglion cells have a sustained response to light and small receptive fields

Which of the following is FALSE? 1) M type ganglion cells have a sustained response to light and small receptive fields 2) ON-type bipolar cells are sign inverting 3) OFF-type bipolar cells hyperpolarize in light 4) Horizontal cells are needed for center-surround receptive fields

1) M type ganglion cells have a sustained response to light and small receptive fields

Which of the following is FALSE: 1) M type ganglion cells have red-green color opponency 2) The pigmented epithelium is required for photoreceptor function 3) The pupillary light reflex is consensual 4) Rhodopsin is a G protein-coupled receptor for light

1) M type ganglion cells have red-green color opponency

Rods are much more sensitive to light than cones because: 1) Rods have a much higher concentration of photopigment 2) Rods project directly to ganglion cells, while cones do not 3) Rods have much larger receptive fields 4) Rods are selectively concentrated in the fovea of the eye

1) Rods have a much higher concentration or photopigment

Which of the following is FALSE? 1) Iris muscles control pupil size 2) Aqueous humor fills interior of the eye ball 3) Ciliary muscles control the shape of the lens 4) The last thing light hits in the eye is the pigmented epithelium

2) Aqueous humor fills interior of the eyeball

Which of the following is FALSE? 1) Ciliary muscles control the shape of the lens 2) Aqueous humor fills interior of the eye ball 3) The last thing light hits in the eye is the pigmented epithelium 4) Iris muscles control pupil size

2) Aqueous humor fills the interior of the eyeball

Which of the following is FALSE regarding intrinsically photosensitive ganglion cells? 1) Have large dendritic fields 2) Hyperpolarize in the light 3) Synchronize brain responses to light 4) Melanopsin is the photopigment

2) Hyperpolarize in light

The blind spot of the retina: 1) Contains rods, but not cones 2) Is where the optic nerve exits the retina 3) Is within the fovea 4) Contains high levels of rods and cones

2) Is where the optic nerve exits the retina

Which of the following is FALSE: 1) OFF-type bipolar cells are sign inverting 2) ON-type bipolar cells depolarize in light 3) P type ganglion cells have a sustained response to light and small receptive fields 4) Rhodopsin is bleached in the light.

2) ON-type bipolar cells depolarize in light

Which of the following is FALSE? 1) M type ganglion cells respond to movement 2) P type cells respond to movement 3) 90% of ganglion cells are of the P type 4) NonM-nonP cells are color sensitive

2) P type cells respond to movement

Which of these conditions is mismatched? 1) Cataracts - clouding of the lens 2) Retinitis pigmentosa - loss of peripheral and night vision 3) Glaucoma - decreased intraocular pressure 4) Macular degeneration - loss of central vision

3) Glaucoma - decreased intraocular pressure

Dark in the surround of an OFF-center ganglion cell would: 1) Inhibit glutamate release 2) Produce maximum stimulation 3) Inhibit ganglion cell firing 4) Stimulate more glutamate release

3) Inhibit ganglion cell firing

Which of the following is FALSE: 1) Rhodopsin is a G protein-coupled receptor for light 2) The pigmented epithelium is required for photoreceptor function 3) M type ganglion cells have red-green color opponency 4) The pupillary light reflex is consensual

3) M type ganglion cells have red-green color opponency

Which of the following statements is FALSE? 1) 90% of ganglion cells are of the P type 2) M type ganglion cells respond to movement 3) P type cells respond to movement 4) NonM-nonP cells are color sensitive

3) P type cells respond to movement

Which of the following is FALSE regarding cones? 1) Are mostly concentrated in the fovea and center of the eye 2) Each of the three types of cones expresses a specific photopigment 3) In the central retina have almost a one-to-one ratio to ganglion cells 4) Are more prevalent that rods in the retina

4) Are more prevalent than rods in the retina

Off-type bipolar cells: 1)All of the responses 2) Are "sign inverting" cells 3) Express metabotropic glutamate receptors 4) Express ionotropic glutamate receptors

4) Express ionotropic glutamate receptors

Dark in the surround of an OFF-center ganglion cell would: 1) Produce maximum stimulation 2) Stimulate more glutamate release 3) Inhibit glutamate release 4) Inhibit ganglion cell firing

4) Inhibit ganglion cell firing

Which of the following is FALSE 1) Photoreceptors hyperpolarize in light 2) Photoreceptors release more neurotransmitter in the dark 3) Ca2+ entering photoreceptors is important for light adaptation 4) Light increases the level of cGMP in photoreceptors

4) Light increases the level of cGMP in photoreceptors

Which of the following is FALSE: 1) P type ganglion cells have a sustained response to light and small receptive fields 2) ON-type bipolar cells depolarize in light 3) Rhodopsin is bleached in the light. 4) OFF-type bipolar cells are sign inverting

4) OFF-type bipolar cells are sign inverting

True or False: Red light in the center of the receptive field would maximally inhibit a green ON center, red OFF surround cell.

False

True or False: Rods and cones are evenly distributed across the retina

False

True or False: Each type of cone has a peak wavelength at which it maximally responds

True

True or False: In color-opponent cells the response in center to one wavelength is canceled by the opponent wavelength in the surround.

True