Sensory Systems exercises

MONASH University Medicine, Nursing and Health Sciences

Visual Transduction II  Unreliable Facts

Instructions: Identify and select the 3/10 correct sentences

  1. Rod cells are more sensitive to light due to their ability to amplify weak signals through a process called phototransduction amplification.
  2. Cone cells, on the other hand, are less sensitive to light and provide us with daylight, colour, and fast-movement vision.
  3. The centre of the retina, known as the infundibulum, contains a high concentration of foveal nerve cells.
  4. The foveal nerve cells are the most sensitive to detailed, high-acuity colour vision but only function in tropic conditions.
  5. Retinal ganglion cells (RGCs) indirectly receive signals from photoreceptors via the horizontal and amacrine relay cells.
  6. The RGCs transmit information as action potentials along the oculomotor, optic and glossopharyngeal cranial nerves.
  7. Bipolar cells contribute to lateral inhibition between photoreceptor and nerve cells, enhancing contrast and sharpening the image.
  8. Dark and light adaptation are mechanisms to optimize vision under varying lighting conditions, and allow the retina (and us) to adjust to changes in light conditions.
  9. Light adaptation depends on the modulation of Ca++ levels within RGCs, to vary their responsiveness to the transmitter released by relay cells.
  10. In contrast, dark adaptation depends on the ability of photoreceptors to produce more opsin molecules to detect the low levels of photons in dark conditions.