Chapter 50 The Eye: II. Receptor and Neural Function of the Retina

Chapter 50  The Eye: II. Receptor and Neural Function of the Retina

Complete Chapter Questions And Answers
 

Sample Questions

1. Which compound is responsible for activation of transducin during photoreception?
A. cGMP
B. All-trans-retinal
C. Rhodopsin
D. Metarhodopsin II

ANS: D

2. During photoreception all of the following increase except:
A. cGMP phosphodiesterase
B. Transducin
C. Metarhodopsin II
D. Sodium influx into the outer segment of the rod

ANS: D

3. Which of the following statements is correct?
A. The total number of cones in the retina is much greater than the total number of rods
B. Each individual cone responds to all wavelengths of light
C. Activation of photoreceptors (rods and cones) results in hyperpolarization
D. The central fovea contains only rods

ANS: C

4. Which best describes the function of the horizontal cells of the retina?
A. The horizontal cells prevent the lateral spread of excitation caused by light on the retina
B. Horizontal cells generate action potentials and transmit this activity to the lateral geniculate nucleus
C. Horizontal cells connect the photoreceptors to the ganglion cells
D. Horizontal cells begin the analysis of the visual seen

ANS: A

5. Which of the following statements best describes the relatively poor visual acuity in humans at night compared to daylight?
A. The central fovea is the area of greatest visual acuity and this area contains only rods
B. The central fovea is the area of greatest visual acuity and this area contains only cones
C. The central fovea contains rods that have a connection ratio of 1:1 with ganglion cells
D. The central fovea, the area of greatest visual acuity, is the exit point for ganglion cell axons which results in greater activation of photoreceptors in this area

ANS: B