The dark current of photoreceptors refers to
A. the exit of Na+ and Ca2+ out of the cell when light is not hitting the cell.
B. the entry of Na+ and Ca2+ into the cell when light is not hitting the cell.
C. the entry of K+ into the cell when light is not hitting the cell.
D. the exit of K+ out of the cell when light is not hitting the cell.
(
Question 2) Visual pathways include axons that project from the optic tracts to the superior colliculi.
Indicate whether this statement is true or false.
(
Question 3) A photopsin is a protein
A. of a photopigment within cone photoreceptors.
B. of a photopigment within rod photoreceptors.
C. that is derived from Vitamin E.
D. that allows ions to flow into rod and cone photoreceptors.
(
Question 4) Most axons within the optic tract terminate in the
A. temporal lobe of the cerebral cortex.
B. occipital lobe of the cerebral cortex.
C. lateral geniculate nucleus of the thalamus.
D. medial geniculate nucleus of the thalamus.
(
Question 5) Phototransduction is the process in which
A. retinal ganglion cells signal changes in the color of light.
B. bipolar cells signal the presence of contrast in a visual scene.
C. photoreceptors convert light energy to changes in membrane potential.
D. primary visual cortex recognizes and identifies a stimulus.
(
Question 6) Sharp, color vision is a result of the function of
A. rods.
B. cones.
(
Question 7) When light strikes a photoreceptor it
A. deporlarizes and releases more neurotransmitter.
B. depolarizes and releases less neurotransmitter.
C. hyperpolarizes and releases more neurotransmitter.
D. hyperpolarizes and releases less neurotransmitter.
(
Question 8) Which photoreceptor cells are more numerous?
A. Rods
B. Cones
(
Question 9) The gelatinous mass inside of the eye is called the
A. lacrimal secretion.
B. mucoid body.
C. vitreous humor.
D. hyaloid mass.
E. scleroid humor.
(
Question 10) Which sequence correctly traces the pathway of aqueous humor in the eye?
a: Aqueous humor is secreted by epithelial ciliary cells.
b: Aqueous humor is released into the posterior chamber.
c: Aqueous humor is drained into the scleral venous sinus.
d: Aqueous humor washes over the lens and then passes through the pupil into the anterior chamber.
A. a, b, c, d
B. b, a, c, d
C. a, b, d, c
D. d, a, c, b
E. a, c, b, d
Quick Reply
