Module 10: Figure ultrastructure of rods and cones
Ultrastructural organization of inner segment membrane systems in rods (left) and cones (right).
Membrane amplification in the rods is achieved by stacking flattened discs on top of each other. In the cones, membrane elaboration is achieved by invaginations of the plasma membrane (arrows point to the openings of these invaginations). Note that the outer segment is devoid of organelles that are packed into the lower inner segment, where the mitochondria are particularly prevalent. Reproduced from Bloom and Fawcett 1968; the original figure was supplied by T. Kuwabara.