Functional Anatomy of Photoreceptors

Question 1

What is Photoreception

Answer 1

Process by which the eye detects light.

Question 2

What do Rods & Cones do as they absorb light?

Answer 2

Their visual pigments change shape.

Question 3

How are Robs & Cones arranged?

Answer 3

Stacked in disc which are embedded in the pigment layer of the retina.

Question 4

What are the functional characteristic of Rods?

Answer 4

• Sensitive to dim light & best suited for night vision and peripheral vision.
• Perceived input is in gray tones only.
  Sum of visual input from many rods feeds into a single ganglion cell & pathways converge, resulting in fuzzy & indistinct images.

Question 5

What are the functional characteristic of Cones?

Answer 5

• Need bright light for activation
• Have one of three pigments that furnish a vividly colored view.
• Each cone synapses with a single ganglion cell, so non-converging, resulting in detailed & high resolution images.