Lesson 707 of 1524
Vision
Light reflected from surfaces is imaged by the eye’s optical system, the cornea and lens, onto the retina at the back of the eye, where photoreceptors detect photons of light energy.
Practice this chapterLight reflected from surfaces is imaged by the eye’s optical system, the cornea and lens, onto the retina at the back of the eye, where photoreceptors detect photons of light energy. In the first steps in vision, rods and cones capture photons to create an electrical signal that is proportional to the number of photons captured.
This process, called "phototransduction," is unusual in that the receptors are depolarized in the dark but become less depolarized (hyperpolarized) in the light. When visual pigment molecules capture photons, it leads to a reduction in the concentration of a signaling molecule, cGMP, which when present activates Na+ channels to allow Na+ ions to enter the photoreceptors and…
receptors — depolarized in the dark but become less depolarized (hyperpolarized) in the light.
Worked example
What does “receptors” mean in Vision?
- 1Use the wording this chapter gives for receptors.
- 2The book says: depolarized in the dark but become less depolarized (hyperpolarized) in the light.
- 3Keep the answer tied to this term.
Result: depolarized in the dark but become less depolarized (hyperpolarized) in the light
Why. That is the meaning this chapter gives for receptors.
Answer with the meaning this chapter gives. A nearby idea from the same book is a different term.
Practice margin
This chapter
A fresh set from this chapter only. Choose 10 or 20. Multiple choice and fill-in, with no repeat inside the set.